Introduction
PEPonline
Professionalization of Exercise Physiologyonline
An international electronic
journal for exercise physiologists
ISSN 1099-5862
Vol 10 No 8 August 2007
| |
Physiology of Fitness and Health Promotion: A 12-Week Program
Aaron Mullally, MA, EPC
Board Certified Exercise Physiologist
Graduate of the Department of Exercise Physiology
The College of St. Scholastica
Duluth, MN 55811
“Lack of activity destroys the good condition of every human being while movement and methodical physical exercise saves and preserves it.” -- Plato
Introduction
Congratulations, you are taking a big step on the way to good health. Taking part in a weight loss program is a good first step on the road to a healthy lifestyle. The body can benefit a lot from this because being overweight can lead to many health complications in the long run. Being overweight is tough on your joints, heart, metabolism, breathing, and many other physiological functions. Being overweight can also be difficult on you psychologically as well, especially with all of the images of how we should look in the media today. Well, we aim here to let you know that it is not about image. In fact, we shouldn’t really put much, if any, emphasis on image; instead, we will focus on how losing weight can benefit your health in the long run.
I am sure you have noticed that being overweight or obese is becoming more and more common today, especially in our society. Unfortunately, we cannot just point a finger at one specific factor. We cannot do this because there is more than one factor and no two people are the same. For some people, there are genetic and medical issues with weight gain, but there is still a lot of ongoing research to try and figure exact nature of these conditions. The vast majority of people need to focus on making what is called a behavioral change. This means you need to make a change in your lifestyle that affects your health, such as eating out a lot, eating lots of junk food, being sedentary, smoking, drinking (excessively), living a hustle and bustle lifestyle, and so forth.
Remember, there is rarely one behavior that affects a person’s weight. It is usually a number of different behaviors that work together to compromise good health. This is the most challenging part of losing weight because we have to change the way we think and the way we live our lives. These behaviors are hard to break because they are trained behaviors that we have probably been doing for most of our lives. So when it comes to weight loss we not only have to exercise our bodies, but we have to exercise our minds, we have to train our minds to think differently as well.
Exercise alone is not enough to lose weight and keep it off. If you go through this program for the next twelve weeks and don’t change your behavior, chances are you will end up right back where you started, over time. The exercise portion of this program will only work if you change your habits outside of the gym. If you come here and exercise as hard as you can and then go home and eat unhealthy or have a few drinks or overeat, then chances are you will not achieve the results that you are looking for.
We don’t expect anyone to give up certain behaviors cold turkey that is why this is a 12-week program. Throughout the course of this program you will be coached on exercise and how to live a healthier life. Remember that for this to work there must be a large focus on life outside of the gym as well, changes have to be made and effort must be put in. We can only show you the door to good health, you are the only one who can open it and walk down the path to good health. We have every bit of confidence in every one of you that this can be done; hopefully you share the same confidence. Good luck and happy trails.
Back to Basics
We all strive for optimal health and conditioning at some point in time in our lives, but with the hustle and bustle lifestyle that the average American lives it can be easy to stray from this path. It can also be easy to get into the mentality that a “quick fix” is more beneficial to accommodate our busy lifestyles’ even though we may not be totally aware of the affects it will have on us in the long run. It is also very easy to get into the habit of constantly eating on the go, trying to grab every low fat food there is or take supplements in place of meals. Then, after years of living this type of hustle and bustle lifestyle, we find ourselves in a rut wondering what we did wrong or what we could have done better to avoid poor health or a chronic condition, such as heart disease or high blood pressure. This does not happen to everyone in America but it does happen, and more often than it should. And, it can be avoided with even the most basic knowledge in total fitness (physical activity, nutrition, and mental/social health).
Disease
At some point in time in our life we will get sick with something, that something could be the common cold or cancer, we just never really know. Even though we cannot predict when we will get sick we can take control of the disease and lessen or get rid of its effects. Six of the top ten deaths are chronic diseases:
1. Heart diseases
2. Cancer
3. Stroke
4. Chronic lung disease
5. Unintentional injuries (car accidents and others)
6. Diabetes Mellitus
7. Influenza and pneumonia
8. Alzheimer’s disease
9. Kidney disease
10. Septicemia
11. Chronic liver disease (cirrhosis)
The diseases that are listed here can either be avoided or controlled by the way we live our life (i.e., by modifying lifestyle factors). One way of doing this is by reducing the risk factors that are not conducive to good health. Some examples of risk factors are: smoking, alcohol abuse, hypertension, poor nutrition, obesity, chronic stress, and much more. People typically have more then one risk factor at the same time because many of these risk factors can cause other ones; an example of that would be someone with chronic stress who tries to drink to calm down, gains a lot of weight and ends up with high blood pressure and/or other complications. Even if we get rid of one or all of the risk factors, we can still get a disease though; cancer is a good example of this. There are people who have never smoked in their entire life but they have lung cancer, so we need to bear in mind that this isn’t a cure-all but a very good preventative technique.
Physical
Being physically fit is a very important part of living a healthy lifestyle. Keeping fit can be very beneficial and even life saving in the long run if it is done correctly. Keeping a good balance of weight and cardio training is important in keeping our metabolism and hearts working correctly and efficiently. Some benefits of physical activity and exercise are:
1. Decreases incidences of chronic illnesses
2. Have more energy
3. Stronger muscles and good flexibility
4. Decrease incidence of injuries
5. Increased confidence and self-esteem
Many people think that physical activity constitutes going out and running all the time, or swimming laps and so on. But with the increase in sedentary lifestyles, physical activity can just be some good old manual labor. Poor fitness, obesity and chronic diseases due to inactivity have become so prevalent today that promoting people to just get off the couch or away from the computer can be a chore.
Nutrition
Nutrition is extremely important if we want to be healthy, and it is very easy to slip up in this category. With the fast paced lifestyle that people live today it is very easy to find quick solutions for eating, such as microwave dinners, take outs, fast foods, fad diets, and much more. Many people also get caught up in eating low calorie, processed foods that are completely unhealthy for you. Many of the foods that are low calorie foods live up to what they say but there is something very important that people overlook or neglect, nutrient density. Many of these low calorie foods are processed, but the process itself strips the food of many nutrients that are essential to good health so we are basically taking in next to nothing.
Supplementation is also very tempting because many supplements are enriched with everything we need or can be consumed in the place of a meal. Fad diets also sound very tempting because they can offer fast weight loss solutions, six pack abs, more energy and a better sex life and other crazy things that people want to hear. All of these are very tempting but what people don’t get is that it is not natural for your body to drop 40 pounds in one month, or to deprive yourself of carbohydrates and so on. These are topics that are very popular and controversial today. Some benefits of good nutrition are:
1. Promotes proper growth and development early on in life
2. Have more energy
3. Have stronger bodies (muscles and bones)
Mental
Stress is our physiologic response to change, good or bad. We all experience stress in our lives whether we like it or not. An example of stress that is out of our control would be the weather. Our bodies adapt to some fairly nice weather and then within a week it may change to cold and snow. That isn’t much time for our bodies to catch up so for a while we feel bogged down, tired, dreary and we tend to get cold a little more easily; all of this occurs because of the stress that results from the changes in the weather pattern.
The stress that we can control is typically the type of stress that becomes dangerous to us because in many instances it becomes chronic stress. In our society today, it is very common to see people living a fast paced lifestyle, trying to multitask to keep up with daily demands and so on. People who live this kind of lifestyle are setting themselves up for many different problems in the long run such as chronic fatigue or chronic fatigue syndrome, having a weak immune system, or an increases susceptibility to chronic diseases. Soccer moms are prime examples of this; they are always on the go, trying to budget time by multitasking, and typically having very short bouts of rest and time to gather themselves.
Stress drains our mind and body. It forces our bodies to constantly burn energy, especially the energy that we have in reserves. Being constantly on the go gives the body little time to replenish the energy that we put out, which eventually leads to fatigue or burnout and could lead to more dangerous conditions like chronic diseases. Here are a few things that people can do to avoid the dangers of chronic stress:
1. Avoid multitasking; just do one thing at a time.
2. Take an hour or more during the day to just relax.
3. Practice relaxing techniques such as yoga or pilates.
4. Avoid people or other stressors that can have a negative influence on you.
5. EXERCISE!!!
Behavioral Changes
This is probably the most difficult aspect of living a healthy lifestyle, whether it is changing or completely getting rid of certain behavior. People typically get so involved in their daily routines and personal habits that getting someone to change his or her behavior could be as difficult as asking a habitual smoker to quit smoking. Change needs to take place, but a newly trained habit must be incorporated, such as buying an apple and granola bar for breakfast instead of a donut. If someone has a lot of time for a certain habit, then, it can be very challenging to change it or to maintain a change. Having a certain habit coupled with a chemical dependency, such as nicotine or alcohol, can be extremely difficult, but not impossible. Cutting a habit such as smoking or drinking takes a lot more time and effort and encouragement than it does to get someone to stop buying donuts. But, keep in mind that both are equal in importance when it comes to changing for the better. A few things to think about when changing a behavior or encouraging someone else to change is:
1. Be positive.
2. Don’t quit cold turkey, do things step by step and be patient.
3. Consult a physician before quitting a habit that is associated with a chemical dependency.
4. Distance yourself from negative external factors such as friends who can be bad influences or the bar scene.
5. Be sure that you are serious and 110% confident in your decision before you make it.
6. Do not try to take shortcuts or take your change lightly, be serious and do it right.
These are just basic ideas and concepts when it comes to starting or maintaining a healthy lifestyle, but none of these should be taken lightly. Living a healthy lifestyle is not something that can be done by taking shortcuts. There is no easy way or a quick fix that can make it happen. Being healthy requires time, dedication and commitment, but not enough to consume every aspect of our lives like some people think. All we need to do is stick to the basics, put in the effort, and the goal of being healthy can and will be achieved.
Making That Big Change
It is time to make those ever so important changes, those changes that will affect your health and well-being. That is why you are here right now, you are here because you are ready and willing to make a change to improve your health and your life, and we commend you for it. Remember that losing weight is about more than just exercise, it is about changing the way you live your life. Exercise is good to shave off fat and pounds, but it is ineffective if there aren’t changes in your lifestyle. Keeping the weight off in the long run will be difficult if changes aren’t made, and remember that this 12 week program is just the start. It will not keep the weight off for good. Only the changes that you make in your lifestyle outside of the gym will determine your success in weight management.
It is important to make good decisions about nutrition because if you don’t, then over time you can develop long-term health problems. In today’s society it is very easy to slip into bad eating habits with all of the easily accessible fast food, food advertisements, and cheap processed food. There are a lot of instant foods you can buy in the supermarkets that are convenient for that fast paced lifestyle, but are they really that beneficial? There are also a lot of fad diets that are convenient for people as well, but do they really work? Does all of this stuff really help? The answer is no, not really. These types of foods offer little nutritional benefits, and fad diets are fads for a reason. They don’t last. When it comes to what foods to eat, stick to natural, unprocessed foods. If it is affordable try to stick to organic produce because pesticides are not used on them. Now, there is chicken in the grocery stores that are antibiotic and steroid free as well, so I would recommend sticking to that. Keeping your diet as natural as possible is ideal but, unfortunately, it can be pricey. So, if organic food on a regular basis is not financially possible, then stick to the produce and whole foods section as much as possible.
If you look at all of the diets, there is one key ingredient that they all eliminate: sugar. To be more specific, they eliminate simple carbohydrates (sugars), that is, the sugars that lead to long-term health problems such as type II diabetes, high blood pressure, and obesity. These types of carbohydrates are also easy to process and are found in many different foods and beverages, especially the ones that people enjoy (such as sodas, candy bars, fruit juices, cereals, donuts, and other types of junk). The only thing these foods have to offer is that they taste good, other than that they are not good for your health and should be eliminated from your diet, especially in large amounts.
A good way to determine if there is a high amount of simple carbohydrates in the food is by reading the ingredients on the nutrition label. Typically the first ingredient that is listed is the most prevalent ingredient in the food. So, if you see high fructose corn syrup first on the list or close to the top, it is a good idea to stay away from that food. It can be difficult at times because of the media, which constantly puts out images of how all this junk food is so tasty and socially acceptable. Well, this is a marketing scheme used by the companies that make the foods, they put out many different advertisements all over the place and the people in them are skinny and happy. Most of the people in the advertisements are models and more than likely don’t drink or eat the products themselves!
Fast foods are another problem in our society for a few reasons. One is because of the media. Once again, they make the food seem great, convenient, and again socially acceptable. You rarely see a commercial or an ad with just one person drinking a Pepsi or eating at Hardees. Also, the food is typically pretty cheap at these places and, frankly, the food taste good. Once again, just because it tastes good doesn’t mean it is good for you. These foods are cooked with a lot of hydrogenated oils, and these oils contain trans fats. Trans fats have been associated with lowering our good cholesterol (HDLs), and as we all know that is not good. Also, the food is very salty which is not good for blood pressure, and a lot of the food is processed, pretty much everything except the vegetables. They are good at throwing out ads about “healthy” foods, like chicken salads or wraps, but don’t be misled. The chicken in those wraps are deep fried so they still contain the trans fats plus they typically don’t use fat free dressing, so don’t let the adds fool you.
Fad diets have also become very prevalent in our society today because of the rapid increase in obesity. Many of the diets offer great results within a short period of time. The problem is that they don’t offer anything that is really great in the long run. Many diets can help you lose weight but, when you get off them, the weight typically comes back. This is called yo-yo dieting. The irony of yo-yo dieting is that it is linked to causing obesity. The exact mechanism of this is unknown, but constantly taking weight off and putting it back on seems to be a risk factor for obesity. So be careful of a diet that promises great short-term weight loss goals because short-term goals should not be the focus here. It is the long-term goals that you should be focusing on.
Another thing to point out is that if you look at many of the diets, you will notice a very similar trend that actually does work. They drastically reduce or eliminate simple carbohydrates. They eliminate all the little unhealthy snack foods, sodas, instant meals, and other types of foods and drinks that contain these types of carbohydrates. They also cut down the number of calories that should be consumed in a day as well. I have heard a few people say: “I live to eat, not eat to live”. I can believe that because of the way we eat here in America, there are a wide variety of foods and many places to access those foods, whether it is a restaurant or a grocery store.
Another problem, especially in America, is the quantity of food that is consumed. I am sure at some point in time you have heard of the clean plate rule; you can’t be done eating until your plate is polished off. This is not a good way to think because when you are full you are full; you should not eat anything else. When you are full your body is telling you, chemically, not to eat, so listen to it. Getting into the habit of not being finished eating until everything is gone is a big reason why obesity is so prevalent today. Proportion sizes here in America are also very big compared to many other places in the world. So if you mix the large portion sizes with the clean plate rule you get a large and unnecessary gain in your daily caloric intake, which is not good. If you exceed you body’s energy requirements chances are you will gain weight. If you exceed your body’s energy requirements and aren’t very active, be prepared to gain weight. So ideally you would want to balance your body’s energy needs and what you take in.
Ideas for Behavior Change
The following ideas for changing behavior are not new. They have been around for a long time. You may have heard your parents say them to you or you may have read them in health books. Each and every one of the suggestions is simple and to the point. Think about it.
1. Do not abide by the clean plate rule!!!!
2. Stay away from simple carbohydrates (sodas, snacks, high fructose corn syrup)
3. Stick to whole foods or natural foods (produce, whole grain bread, meats without steroids/antibiotics)
4. Do not yo –yo diet
5. Stay active, use stairs more often, get out and walk more, etc.
6. Keep your calories to about 1800 – 2100 per day
7. Exercise!!!
8. Stay away from fast food
9. Find a partner or group of people to exercise with
10. Stay positive, the weight was put on but can be taken back off
11. Don’t expect fast results, it takes 3,500 calories just to burn 1 lb of fat so just keep working at it, you will see results
12. Stay away from over the counter or easily attainable weight loss supplements, they are not as strictly regulated by the FDA as prescription medications and may be hazardous to your health
13. Don’t live to eat, eat to live
14. Avoid going out to eat too often
15. Try to be in smoke free environments as much as possible
16. Do not drink alcohol in excess (1 12 oz can of beer, 1 5 oz glass of red wine or 1 1.5 oz shot of liquor per day)
17. Don’t feel pressured to do things that you don’t want to do (like ordering something on a menu that is not healthy or having a few drinks with friends)
18. Make sure you exercise at the correct intensity to burn fat (70% of your Hr max)
19. Focus more on burning fat than losing weight; it is the excess fat that causes health problems and that increased your weight. So concentrate on getting your lean mass up (everything but fat) and your fat mass down.
20. Stick with it, do not give up or get down on yourself if you don’t see results right away, they will come if you stick with it and work hard.
Being Overweight
When you think of being overweight, think of body fat. Being overweight is defined as having more body fat than is needed. Being obese is having so much body fat that it is detrimental to our health. Here is a list of health complications that obesity can bring about:
1. Cardiovascular disease (hypertension, atherosclerosis, chronic heart failure, etc.)
2. Joint problems (osteoarthritis, arthritis)
3. Type 2 diabetes
4. Sleep apnea (pauses in breathing during sleep)
5. Difficulty breathing, shortness of breath
6. Metabolic syndrome (syndrome X)
7. Varicose veins
8. Depression
9. Poor self esteem
Bare in mind those these are only a few of the complications that obesity can bring on. Also, remember that being overweight does not bring on nearly as many complications as obesity but being overweight is a risk factor for it. So this begs the question, what is considered obese? Well there is a body composition measurement technique called the body mass index (BMI) that was created by a Belgian statistician named Adolphe Quetelet in the mid 1800's that people use quite frequently today. [1] The BMI is a calculation that is used based on an individual’s weight and height; it is used to gauge a person’s proper weight based on their height. The BMI is good to categorize where people should be but it has its flaws. The BMI does not assess your physiology at all, it does assess your body fat composition and can also be inaccurate because it does not gauge how good of shape you are in; the BMI is geared towards the normal sedentary population.
Remember that the amount of body fat is the main concern here, not weight in general. Also, the location of the body fat is equally as important. High levels of fat in the abdomen are typically considered a major risk factor for the diseases that were listed above. So when you partake in this program you should focus more burning your fat. During the course of this program you may gain a little weight, which is ok. Since you are lifting weights your muscles will probably grow a little larger (not much though) and if your muscles grow your bones may become a little thicker as well. This is ok and it is natural so don’t be alarmed. The main goal here is to get rid of the body fat and to make the necessary lifestyle changes that will help you to maintain your health in the future. As you burn the fat you will lose weight so do not put a lot of emphasis on just losing weight.
Standards
BMI Standards
• < 18.5 is considered underweight
• 18.5 - 24.9 is considered normal weight
• 25.0 - 29.9 is considered overweight
• 30.0 - 39.9 is considered obese
• 40.0 or higher is considered morbidly obese
How to Calculate BMI
|Metric Units |“American” System |
|mass (kg) |703 x weight (lbs) |
|height² (m) |height² (in) |
1 pound = 2.2 kg
1 inch = 2.5 cm
1 meter = 100 cm
Example: A man who is 5'8" who weighs 200 pounds decides to lose weight. During the assessment the health care professional takes his BMI, what is his BMI?
Ideal Body Fat Percentages
Men: 12% - 23% = healthy
Women: 16% - 28% = healthy
*A person who is 10% - 20% over their desired weight is considered overweight
*A person who is 20% or more over their desired weight is considered obese.
Carbohydrates: The Good Guys
Contrary to popular belief carbohydrates are the good guys and are extremely important to our everyday physiology. Our bodies are machines, much like automobiles, and like automobiles we need fuel to keep ourselves running. Carbohydrates are our main source of fuel; our bodies access carbohydrates before our other substrates, such as fats and proteins. Carbohydrates are used to keep our metabolisms running, act as our main source of energy during exercise (this varies with the intensity of the exercise), provide structure (chitin), resist pulling forces (cellulose), and act as cell markers. So if carbohydrates are so vital to us why do they have the bad rep, and why do people want to go on low carb diets to avoid them? The answer is because carbohydrates are in a lot of food, and there are carbs to stay away from and carbs to go after, unfortunately the carbs we should stay away from more taste very, very good and are not a problem to eat. Like anything else out in the nutrition world if we eat carbs in moderation and eat the right ones we will be fine. Unfortunately there are many, many people out there that don’t do that and end up very unhealthy bodies, so this begs the question: which carbs should we eat and which ones should we stay away from?
Classifications
There are a few different types of carbohydrates but we will focus on the ones that give us energy and affect our health. There are two types of carbohydrates that we mainly focus on; they are simple and complex carbohydrates. These are classified based on their chemical structure and they both have different affects on the body. Simple carbohydrates can be broken down into monosaccharides and disaccharides. Monosaccharides are just one lone molecule of sugar, such as the ever-popular glucose; the other forms are fructose (fruits) and galactose (milk). Disaccharides are two monosaccharides linked together by what is called a glycosidic bond, and the sugars are maltose, lactose (milk) and sucrose (table sugar). Simple carbs are broken down and/or absorbed faster and enter the bloodstream much faster. These types of sugars are associated with having a high glycemic index and are associated with chronic diseases over time, such as diabetes, heart disease, and some types of cancers.
Complex carbohydrates are the carbs that we should put more focus on in our diet. A complex carbohydrate is three or more sugars linked together in a chain; the other name for these is polysaccharides. We typically focus on starch, the plant form of stored energy. These are associated with a low glycemic index because these take longer for the body to break down due to the number of glyosidic bonds. Since the body breaks complex carbs down at a slower rate they are released into our bloodstream at a slower rate, once again leading to a lower glycemic index. This concept will be discussed in more detail later on.
Carbohydrate Digestion
Carbohydrate digestion begins in the mouth and ends in the small intestine. There is an enzyme called amylase that starts to break down starch until the food reaches the stomach. Due to the highly acidic environment in the stomach the carb digestion comes to a halt, for now. Once the food mixed with the acid leaves the stomach through the duodenum it reaches the small intestine, the pancreas secretes a substance called bicarbonate to neutralize that high acid content from the stomach; and the mucus in the small intestine also helps with this as well. This is important to know because carbohydrate digestion is halted until the acidity from the stomach is neutralized. Once the acid is neutralized the digestion can continue thanks to the amylase that is secreted into the small intestine from the pancreas. The amylase breaks down the polysaccharide chains into simple sugars, or oligosaccharides (three to eight sugar molecules linked together), which are then absorbed by structures in the wall of the small intestine called villi. There are enzymes in the villi as well that can break down carbohydrates even more so they can be absorbed into the bloodstream more easily. Once the sugars are broken down they can be absorbed by the capillaries in the villi, and then are taken to the lymph or directly to the bloodstream. Once the sugars enter the bloodstream they are taken to the liver for the final stage of digestion. After a meal, blood sugar levels are fairly high so the pancreas secretes insulin, which causes the liver and muscles and other cells to take in the sugar for storage and other usage. If the blood sugar level starts to drop due to starvation or exercise, the pancreas will secrete a hormone called glucagon, which stimulates the liver to enter into a process called gluconeogenesis (i.e., a process where the liver breaks down glycogen to make glucose or it stimulates the liver to make glucose from certain amino acids or a little bit from fats as well).
Carbohydrates and Exercise
For the most part, the body stores glycogen in the skeletal muscles and liver, plus their is some glucose in the bloodstream at all times as well. This is enough energy to last us for a good hour or so, depending on how well trained a person is and the intensity of the exercise. After that, a person must consume carbs during exercise in order to sustain it. It is really important for athletes who compete and train for endurance sports such as cross country running or skiing, cycling, swimming, triathlons, and so on to focus on carbo-loading. Research has also shown that sports involved with burst activity such as hockey and soccer should also focus on carbo-loading. This doesn’t mean that people who only exercise at moderate intensities shouldn’t worry about their carb intake as much as a marathoner; it just means that they don’t need to take in nearly as much. People who exercise at moderate rates still burn carbs, but not at the same rate that someone who is exercising at more intense rates.
Remember the crossover concept, this is where the body is burning more fats than carbs at lower intensities of exercise, but it is still burning carbohydrates. As a person increases exercise intensity, the body increases the rate it burns carbs (which is more rapidly than fat because carbs are much easier to access and it takes less energy to break them down). This doesn’t mean that a jogger should not worry about carb intake though; remember a person needs carbs for more than just exercise. The brain needs carbs more than anything; plus a jogger is still going to have to replace the carbs that were burned during the exercise, just not as much as a marathoner. Here are some ways exercise can benefit our carbohydrate metabolism:
1. Increase the efficiency of oxygen consumption
2. Operate for longer periods of time at higher intensities
3. Increases GLUT~4 in our muscles, which spares our glycogen during exercise and increases restoration of muscle glycogen after exercise
4. Increase in muscle cell mitochondria
5. Increases fat metabolism and crossover point
6. More glycogen is stored in the muscle [1]
Carbohydrates and our Health
Carbohydrates have been a big topic recently in the health field. Many people are stating that carbs are the bad guys and others say they are the good guys, which is it? Carbohydrates are the good guys, but over consumption of or eating the wrong ones can lead to long- term health problems. The simple carbohydrates are the ones that are linked to long term health problems and because of this we should limit our intake of them. Simple carbohydrates are released into our system much faster than complex carbs, which stimulates our pancreas to release more insulin to lower our blood sugar. Over time if we constantly eat too many simple carbs our body will become less sensitive to insulin and eventually lead to type II diabetes, obesity, heart disease and other diseases as well. Remember that insulin stimulates cells to take in glucose, and adipose tissue (fat) is one of those types of cells. The excess glucose in the blood is stored in the liver, skeletal muscle and in the fat, and if there is no room in the liver or muscle for glucose it goes into the fat. Since people who are sedentary don’t burn much of their glycogen stores most of the glucose goes into the fat cells which will lead to obesity and other problems over time. Our cells become less sensitive to insulin due to a process called down regulation. Down regulation is when our cells stop bringing a certain receptor to the cell surface; there are two causes of this, very little of the hormone in the blood or too much exposure to the hormone. This is considered one of the main causes of type II diabetes. Fortunately this disease can be brought under control and possibly reversed through exercise and a higher intake of complex carbs.
Complex carbs are important for us because they are broken down at a slower rate and therefore absorbed into our bloodstream at a slower rate, which means they have a lower glycemic index. This is beneficial for exercise because if we eat foods that have a high glycemic index before we exercise our body will release insulin to lower our blood glucose levels, which will in turn start to lower the amount of energy we have for exercise. Eating complex carbs are beneficial to our overall health because they don’t typically lead to insulin sensitivity, and are stored more efficiently as well. The promotion of complex carb consumption is also implemented in weight loss programs along with exercise to help reduce weight and manage type II diabetes if necessary.
Nutrition
Carbohydrates should be number one in our daily caloric intake by a long shot. Carbohydrates should constitute at least 60% of our total caloric intake throughout the day to meet our body’s energy needs. Here is how to calculate it:
1. First drop a zero from 2000 to make it 200
2. Next step: 200 ( .60 = 333, we’ll round down to 300
3. 1 g carbs = 4 calories, so 300 x 4 = 1200 calories
Some researchers say that we need at least 200g of carbs each day just to sustain proper brain function alone, but this is not a solid fact yet. When it comes to complex carbs 50 of the 60% daily intake should be complex carbs, and only 10% should be simple carbs. Unfortunately in our society, it is very common to see these numbers flipped around, which is one reason why obesity is so prevalent.
Another reason complex carbs are important to us is they are loaded with fiber. Fiber comes in two forms, soluble and insoluble; we mainly consume insoluble starches in our diet. Bacteria in our colon eventually break down soluble fiber while the insoluble fiber passes through our colons, irrigating them along the way. A good analogy for insoluble starch is a snake that we use to clear out our pipes in our homes, as insoluble starch passes through our colon it cleans and clears it out. Fiber also slows down the digestion process so sugars are released into our system at a slower rate as well. A diet that is high in fiber is considered one way to prevent colon cancer in the future, but remember this is not bulletproof since there are still some mysteries associated with cancer, but every little bit helps.
Oh No, Fats!!
Are fats the enemy or the adversary? Do they lead to problems or help solve them? Well, the answers to these questions really depends on us, how much and which ones we consume. Fats, also known as lipids, serve many useful purposes in our bodies; in fact we would not survive without them. If fats are so important to us though, why are they such a big issue in the health world, why the bad rap, and why do people go to such great lengths to avoid them? People go to great lengths to avoid fats because in excess they can be a major risk factor to our health and can help guide us into chronic diseases such as adult onset diabetes (NIDDM or type 2), heart disease (atherosclerosis, CAD), pancreatitis and many others. Some people are destined to get diseases associated with fat because of genetics, but many others manage to eat their way into one or two. Like anything else, moderation is the key but in our society that concept is well forgotten.
The three most important lipids to us are phospholipids, triglycerides and cholesterol. All of these serve very important physiologic roles during rest and during exercise if we consume the right amounts and right kinds we will be just fine.
Phospholipids
Phospholipids are very important to our cells; in fact they are one of the main constituents of our cell membranes. Phospholipids are unique because they are what are called amphipathic that means that one end of the molecule likes water (hydrophilic) and one is afraid of water (hydrophobic). Our cell membranes form a bi-layer, that means that there are two sides to it, and there are phospholipids on each side. The hydrophilic portion faces the outside and the hydrophilic ends, or tails; there are two tails on each molecule, face the inside of the membrane. This bi-layer surrounds the entire cell and acts as a wall to protect the cell from anything that isn’t supposed to enter. There are also different proteins that are in the membrane that act as receptors for molecules that are supposed to enter the cell.
The convenient thing about phospholipids is that a person doesn’t need to worry about them in the diet because they are not essential nutrients (nonessential). The liver uses the triglycerides to make phospholipids so we don’t have to worry about them in our diets.
Triglycerides
Triglycerides are a very big topic in the fat world. Triglycerides are formed when an alcohol called glycerol binds with three fatty acids, the bond is called an ester bond and since there are three tails there are three ester bonds, hence the name triglyceride. The main focus is on the fatty acid tails because these determine the name and properties of the triglyceride. If all of the hydrogens are present and there are no double bonds between any carbons then it is called a saturated fat. If there is one hydrogen missing and one double bond then it is called a monounsaturated fat, and a fatty acid with more than one hydrogen missing and more than one double bond on the tail is called a polyunsaturated fat. When a hydrogen is missing, a kink forms in the spot on the tail where the double bond takes place, so if there are more than one double bonds there is more than one kink. When this form is taken, then storage becomes more difficult. It would be like trying to stack a bunch of logs on a truck without cutting off the branches first. So, when a bunch of polyunsaturated fats are “packed” together, they form a liquid or a oil. When saturated fats are put together, they for more solid substances like margarine or butter.
There is a process that is called hydrogenation that scientist use to make foods last longer and easier to shape and store. This is done by taking an unsaturated fat and forcing hydrogen into it (hence, the name hydrogenation). This takes the kink/s out of the fatty acid tail and makes the substance more solid and easy to store, plus it increases the shelf life of the product. The fat is called a trans fat because there is a spot where a double bond still exists but the hydrogens are not on the same side.
We need triglycerides but not too much, if our triglyceride levels get too high they tend to lower our HDLs a.k.a. good cholesterol levels. Unfortunately the exact mechanism that makes this takes place is unknown, so for now high triglyceride levels are correlated with low HDLs.
Cholesterol
Cholesterol probably has the largest amount of hype in the health world today, at least when it comes to fat. Cholesterol is essential to our everyday lives. Without it we would be dead. Our bodies make plenty of cholesterol, and are very cool machines because if we eat more cholesterol than we make our bodies will slow down the production, and if we don’t eat enough our body will try to compensate increasing the amount cholesterol that it produces. Cholesterol has a few functions that are essential to our everyday lives:
1. Arranged in an organized and uniform in our cell membranes, this helps maintain their fluidity and stability.
2. Cholesterol is a precursor to our steroid hormones: mineralcorticoids, glucocorticoids, sex hormones (progesterone), testosterone and estrogen, and vitamin D.
3. Helps our cells take in materials from the outside environment (endocytosis).
4. Used in cell signaling, and
5. Used to make bile, which aids in the digestion of fats.
Cholesterol is transported through our bodies via high density lipoproteins (HDLs) and low density lipoproteins (LDLs). The LDLs carry cholesterol and triglycerides all over the body to where it is needed while HDLs carry cholesterol back to the liver to be processed. Having high levels of LDLs and low levels of HDLs is considered a risk factor for heart disease, but the exact cause behind this is still unknown. The best explanation so far is that HDLs can carry cholesterol away from what are called atheromas, which will be explained soon, back to the liver, so having a high number of these and a low number of LDLs should be able to help prevent heart disease.
Cholesterol is associated with a very common form of heart disease called atherosclerosis. This is caused by the buildup of three things in our arteries: plaque, cholesterol, and calcium. This actually starts in early childhood, between the ages 5-10 and continues throughout life. The plaque is built up on what are called fatty streaks that line the arteries, and these streaks are what lay the groundwork for this to happen. The fatty streak is like laying down your cement foundation when you build a house, and the addition of plaque and calcium over the years is like the actual building process. Our arteries can adapt to this because they are elastic in nature, they have to stretch when blood is pumping through them and can stretch while this plaque is building up in them as well. Over time though when our arteries cannot stretch anymore they start to narrow while the plaque continues to build, this is called stenosis. The more narrow the artery gets the more the blood flow is reduced, forcing the heart to increase the blood pressure, and eventually a clot can get stuck in the plaque, cut off blood flow and lead to a heart attack or a stroke. Also if the artery bulges out too much an aneurysm can occur over time as well.
LDLs are considered problematic here because they deliver cholesterol in all of the tissues, including the smooth muscle that lines the arteries. Once the LDL enters the smooth muscle and releases its cholesterol, which is processed (oxidized); this stimulates the arteries to become inflamed. This really becomes a problem when are HDLs are low because they need to be there to carry the cholesterol away from the tissue and back to the liver, so this is why it is good to have a high number of HDLs and a low number of LDLs.
Preventing Heart Disease
Here are some guidelines for fighting cardiovascular disease (CVD, also known as coronary heart disease, CHD):
1. Adjust caloric intake to achieve and maintain ideal body weight. A very common cause of high triglycerides is high body fat, especially in the abdomen. The fat breaks off and gets into the hepatic artery and is circulated into our system. So just reducing our body weight/fat can be a big help [1].
2. Reduce the amount of total fats in the diet. Keeping our fat intake less than 30% of our total caloric intake is ideal. The calories that replace the fat that we are cutting off should come from carbohydrates, especially complex carbs that contain fiber. Eating monounsaturated fats and omega-3 fats along with aerobic (endurance) exercise will also help to reduce our lipid levels [1].
3. Reducing saturated fats has been recommended for a long time but lately this has found some scrutiny because of many original tests that were conducted with saturated fats. Many scientists are now saying that when saturated fats were mentioned as a risk factor trans fats were mixed in with these so the test results were not accurate. Some people are also saying that saturated fat is beneficial for us, but if we want to be on the safe side if we avoid saturated fats our chances of avoiding trans fats increases as well [1].
4. Reduce the consumption of hydrogenated or partially hydrogenated oils. There is a correlation with consuming these and lowering our HDL levels because of the trans fats. Foods that contain trans fats are: margarine, vegetable shortening, white bread; packaged goods such as cookies, crackers, potato ships, and cakes; and fried fast foods like French fries [1].
5. Substitute saturated fats with poly and monounsaturated fats (PUFAs). Consume 10% or less of our dietary fats from polyunsaturated fats and 10-15 % from monounsaturated fats (MUFAs). Eating nuts, such as walnuts, are a good source of both of these types of fats while olive and canola oil are high in MUFAs. Vegetables are also good sources of PUFAs [1].
6. Consume foods that are rich in omega~3 fatty acids. These are said to help prevent CHD (coronary heart disease) by making our blood less viscous, increasing HDLs, and by increasing the tone of our vascular system. These are said to help reduce the incidence of CHD but still is not a set in stone idea yet [1].
7. Decrease cholesterol intake to 300 milligrams per day or 100 milligrams per 1000 calories consumed [1].
8. Reduce the intake of refined sugars and eat more foods with complex carbohydrates and dietary fiber. Table sugar can increase our triglyceride levels more than complex carbs can. Also, increase the intake of fruits and vegetables, especially fruits because they contain antioxidants that can help combat some negative outcomes of fat oxidation (PUFA and MUFA) [1].
9. Graze throughout the day, this means eat a little bit of food at a time instead of eating just the three meals a day [1].
Daily Intake
According to the National Research Council, there is no recommended RDA (recommended daily allowance) for fats. [1] There are two kinds of fats that are essential though, they are an omega~3 fatty acid called alpha linoleic acid and an omega~6 fatty acid called linoleic acid. [1] Even though there isn’t an exact RDA for fats, it is recommended that we do not exceed 30% of our total calories as fat. Here are some easy steps to determine your daily intake of fat:
2000 Calorie diet
2000 x .3 = 600 Calories
1g fat = 9 calories
600 ( 9 = 66.6 grams
Amounts per serving
Calories = 90
Fat Calories = 30
a) 30/90 = .33
b) .33 x 100 = 33%
More Detailed
Calories = 90
Total fat = 8g
Saturated fat = 3g
Remember that 1 gram (g) of fat = 9 Calories
Total fat = 8g x 9 Calories/g = 72 Calories
Then just use the same procedure as you would for the amounts per serving:
72/90 = .80 .80 x 100 = 80% fat Calories
It is recommended that we eat 100 milligrams (mg) of cholesterol per 1000 calories each day.
2000 Calorie diet = 200 mg/day
Proteins, Cool
Proteins come in many shapes and sizes and perform many functions in our body. Proteins can act as receptors for hormones or other substances, give shape to virtually every 3-D structure in our body, give mechanical support, regulate our metabolism via enzymes, act as hormones, form blood clots, are cellular machinery (which is important in muscle contraction) and perform many other functions in our physiology. So in knowing that proteins are composed of only 20 or so different amino acids one may beg the question: “How can they perform so many functions?” The answer to this is variety; the number of shapes that proteins can take is almost unlimited so it is easy to see why they can perform so many different tasks. Proteins are not only important in our everyday functions but also help us in exercise too, but how much? Before we get into that we should look at how proteins are made first.
The Secret Code
DNA is ultimately responsible for our protein; it carries the code that determines the arrangements of the protein’s building blocks, amino acids. Once again there are only 20 or so amino acids but their arrangement is determined by DNA. So during the process of translation (this is the process of making proteins) amino acids are put together in a line, this is called the primary structure and the structure itself is a polypeptide chain. This is the shape that many of our hormones take; they travel around our body in the primary structure and carry out their specific functions wherever they are needed. The next shape proteins take in their synthesis is called their secondary structure. This is when proteins actually start to form a three dimensional structure as a result of the polypeptide chains bending and twisting, well on portions of the chains. The two shapes that are common with secondary structures are alpha helixes and beta pleated sheets. Alpha helixes don’t resist pulling forces very well, but can eventually regain their shape when the pulling stops; an example of this is wool. The beta pleated sheets on the other hand can resist pulling force very well; this is what silk is primarily made of. Next in the process of protein development is the tertiary structure; this is where proteins actually start to become their actual shape, and this is where the diversity card is really played. When proteins form their tertiary structure different polypeptides and other proteins in their secondary structure start to come together and the protein actually folds as well. This is important to know because if a protein is off by a single amino acid or misfolds, the result could be death. Last but not least is the quaternary structure, this is where folded proteins glob together and make one big structure, such as hemoglobin or an enzyme.
All of that may seem like a bit much and may not seem relevant to what you all are looking for but it this is relevant. Like I mentioned earlier, even one amino acid in the wrong place or one incorrect fold can lead to a myriad of problems, the classic example of this is sickle cell anemia. The amino acid valine replaces a glutamic acid (also an amino acid) and this causes our hemoglobin to go haywire. Since the hemoglobin can’t take its proper shape, neither can the red blood cell. Remember that our red blood cells carry substances throughout our body, and one of those substances is oxygen. This lowers our red blood cells capacity to carry oxygen and so far we do not have a cure for it.
Exercise
Proteins are important for exercise, but more for their structure than the energy they can provide. Again, everything that we use for exercise (muscles, bones, hormones, neurotransmitters etc.) is made of proteins, so our chemical and mechanical forces come from proteins. The big question is though: how much energy can we get from proteins? The answer is very little. As we know from previous lectures our bodies use a certain ratio of carbohydrates and fats when we are at rest and during exercise. The ratio just changes as our intensity of exercise increases. Our bodies use a little protein when we are exercising, but not much, at least not enough to yield a significant amount of energy.
This doesn’t make proteins useless during exercise though; the amino acids can be used for other purposes that help us during exercise. One is by providing our energy production systems (metabolism) with the proper tools to make energy. When our body is making ATP for energy, there are certain intermediates (tools) that are used, but unfortunately they get used up, and when this happens our body cannot make energy properly and we start to fatigue. Amino acids from protein breakdown can help support our energy making processes, thus buying us some more time during exercise.
Some amino acids can also be converted into sugar (glucose) by being transported to the liver. Our muscles can also release an amino acid (alanine) into our bloodstream, which goes to our liver and is made into sugar through a process called gluconeogenesis (gluc- sugar, neo- new, genesis- to make). During very prolonged periods of exercise our muscles can use amino acids themselves as energy, but this usually occurs in highly trained athletes who have a high carb/protein diet.
Nutrition
Many people think that bacteria are small, and in many ways insignificant, but the reality is biochemically bacteria are our superiors. Bacteria can survive in environments that we cannot even enter because they are so extreme, they can eventually become immune to our ways of killing them and they can make all of their nutrients themselves. Bacteria can synthesize all 20 amino acids while we can only make eleven. The eleven amino acids that we can make are called nonessential because we do not need to consume them while the nine that we do need to take in are called essential amino acids. Another thing to keep in mind is that there are foods that are complete protein and foods that are incomplete. The difference between these are: foods that are complete protein sources have all the amino acids in them that we need while foods that are incomplete lack one or more amino acids. This is important to know because our bodies will only absorb the amino acids if all of them are present and accounted for. The majority of us don’t have to worry about this though because meat is a complete protein, all of the essential and nonessential amino acids are in meat, so just by eating meat alone we can get an adequate amount of amino acids. Some other foods that are good sources of protein are: milk products, nuts, legumes, and peas. Many fruits and vegetables also have proteins in them but they also lack all nine essential amino acids making them incomplete proteins; which is why we it is good to eat a variety of different foods in our diets.
There really is no RDA for protein consumption, but we should still be conscious of what we are eating. Remember that meats, especially red meat and pork, can be high in saturated fat and contain high levels cholesterol, and have a lot of sodium in them as well. Also the way we prepare our meats can have an affect on us as well, whether it is what we put on them for flavor or how they are cooked. Even there is no RDA for proteins there are still recommendations, but these also vary with age. For all of us the recommendation is 0.8 grams/kg or body weight or .36 grams/pound of body weight. Here is how to calculate this:
Grams/kg:
0.8g of protein x (bw ( 2.2) = grams per day
Example: 0.8g/protein x (180lbs ( 2.2) = 65.44 grams protein/day
1 gram of protein = 4 calories
65.44 x 4 = 262 calories of protein per day
Grams/pound:
.36 g/protein x pounds = grams per day
Example: .36 x 180 = 64.8 grams of protein/day
64.8 grams/day x 4 = 259.2 calories of protein per day
Guidelines for Using the Exercise Room
• Dress appropriately; wear clothing that is comfortable, that can breathe, and that can offer you full range of motion when you are working out.
• Wear appropriate footwear; don’t wear outside shoes and wear shoes that fit your feet correctly, and ones that offer the best support for your foot to prevent injury.
• Always have a water bottle with you so you can keep hydrated while you workout.
• Always do a warm up to ensure that you get adequate blood flow to your muscles and prevent injury.
Guidelines for Using the Weights
• Work your upper body three days a week and your lower body two days a week, your legs need more time to recover after a lifting day
• Add variety to your workouts, don’t just work the same muscle groups and don’t do the same exercises all the time
• DON’T LIFT WEIGHT THAT YOU CANNOT HANDLE!!!
• Use etiquette when you lift, put everything back where it belongs, such as: weights, bars or other equipment that may have been used.
• ALWAYS HAVE A SPOTTER!! Don’t be afraid to ask a random person or an employee at the gym to spot you, they will be more than happy to help.
• When you perform a lift do so in a controlled motion; the motion should be: 2 seconds up from the starting point and 4 seconds back down.
• It is natural to feel some soreness while you lift; this is your muscle fatiguing. If you feel any sharp pain or any other kind of pain that you are unfamiliar with stop the exercise right away and locate a staff member.
• If you feel any chest or jaw pain stop the workout immediately, locate a staff member and seek medical attention if necessary.
Guidelines for Using the Cardio Equipment
• Use a setting that is right for you, don’t over do it on the machines because you could injure yourself and someone around you as well.
• Pay attention to what you are doing; focus more on the machine that you are on, not the television or someone around you.
• There is no shame in taking a break if you need to, overworking yourself can cause injury and also cause you to not want to use the equipment.
• Vary your workouts, don’t over work yourself and don’t just putz around, you need to get a good quality workout while you are here
• If you feel any “bad” pain, stop your workout immediately and find a gym employee
• If you feel any chest pain or jaw pain stop your workout immediately, find a gym employee and seek medical attention if necessary.
These are some basic guidelines to follow when working out to ensure proper safety and a quality workout. The gym is a great place to improve your health, lower your risk factors for chronic diseases, and to meet new people. If the exercise equipment is used properly, it can provide you with all of your exercise needs; the gym here as more than enough to get you headed in the right direction. Also, if you have a heart problem, type I or II diabetes, or any other medical condition you should see your physician so he can clear you to exercise and give you guidelines to exercise by. If you have any questions about anything in the gym do not hesitate to ask a personal trainer or other staff at the gym, there is no shame if you don’t understand how to do something. We are here to help you get the safest and most quality workout you can get so feel free to utilize us at any time.
Exercising
Many people exercise or train for a variety of reasons such as losing weight, preparing for a race, or just for the enjoyment. Everyone has one reason or another to exercise, but the question is how do you exercise? How would a person really prepare for a race or lose weight? Well there are different ways to go about each one of these but there are some basic guidelines that everyone can at least appreciate. Also, knowing how cardio (aerobic) and weight (anaerobic) exercises benefit us is a big tool in all of this as well.
Aerobic (Cardio) Exercise
There is a reason that aerobic exercise is called cardio and that reason is right in the name. Cardio really works on making your cardiovascular or cardiopulmonary (heart and lungs) systems stronger than they were before you started exercising. Our hearts really take in a lot of the benefits because it becomes a stronger, more efficient piece of equipment in our body. The heart becomes bigger which means that the ventricles (chambers) that lie inside of the heart get bigger, which means that more blood can enter our heart. Since our hearts are getting bigger, they are getting stronger as well. Since the heart is stronger it can pump blood with more force and get it out into the body much easier than before exercise. This is great because our blood pressure drops when this happens because our heart does not need to work as hard to get the blood out of our hearts and into our periphery, so this is a good way to combat low blood pressure.
Cardio exercise is also good for burning fat if it is done correctly. It is logical to think that exercising for a longer period of time will burn fat, but how should we utilize that time? Well the intensity that we exercise at is just as important as the amount of time we spend exercising because we need to maintain a certain level of intensity during that period of time. The gold standard is for that is a minimum of 70% of your maximum heart rate. This is relatively easy to figure out, there are two popular ways of doing this; the first is the Karvonen method:
THR = [(HR max - HR rest) x % intensity of the workout] + HR rest = THR
First you need to figure out your maximum heart rate (HR), and the easiest way to do this is by taking 220 minus your age.
Example: 220 - 24 = 196 bpm
[(196 - 60) x .70] + 60 = 155 bpm
This method should be used if you do not know your maximum heart rate. The other method is the called the Simple Method:
THR = HR max x % intensity
Example: 196 x .70 = 137
You will notice that these two methods yield different results; that’s nothing to be afraid of. The Karvonen method is considered more accurate than the simple method when calculating your target heart rate for exercise. These two methods are really the best non-invasive ways to figure out your maximum heart rate and your target heart rate.
The reason that people should work at 70% of your maximum heart rate is because of the way we burn energy and the way our hearts work. Exercising at 50-60% of your maximum heart rate is still just fine to maintain a healthy heart, but if you really want to focus on your metabolism and weight loss then 70% should be the main focus. When you exercise at 70% of your maximum heart rate, you burn more food energy. [1] When we work at this intensity we are still burning about 75 - 85% (depending on what you read) fat for our energy needs, so this is a great way to lose weight and become leaner. The amount of time that a person should train also varies with the organization or research that you get the information from, but the bare minimum should be 20 minutes of cardio (aerobic) exercise at 70% of your maximum heart rate to achieve good cardiovascular benefits and calorie expenditure.
Weight Training (Aerobic Exercise)
Aerobic exercise is exercise that consists of very short, intense bouts of exercise that is maintained for very short periods of time. This type of exercise includes: weight training, sprinting, and jumping; we will mainly focus on weight training for this particular informational session. Weight training is very beneficial and should be incorporated in your exercise program as well as the cardio. Weight training helps to increase our lean mass, this means that our muscles become larger and stronger; remember from previous talks? Weight training also makes our muscles more efficient as well because our nervous system has to adapt as well. When we lift weights, our peripheral nerves (the nerves that branch out from our spinal cord and out into our body) have to adapt as well. They adapt by adding more motor units to the muscle; a motor unit is an extension of the neuron that activates the muscle that it corresponds with. If our muscles get bigger and stronger, then our neurons (cells of the nervous system) need to add more motor units to the muscle fibers, this is done to activate more of our muscle in response to the extra force.
Lifting weights is also good because it can help to prevent injury by making our muscles stronger so they can support our bones and joints during exercise. Weight training will help our muscles support our joints and protect them from injury, and keep the joints more stable as well.
Lifting weights also helps keep our bones strong as well; the force that is put on our bones makes them have to lay down more tissue and become stronger and more stable so they can withstand the force in the future. Running can also do this as well because of the constant pounding that our feet and legs have to endure.
Now when it comes to lifting weights it is logical to think that the more weight we lift the more we will bulk up. People usually associate this with losing endurance and that is correct if you cut your cardio out. Gaining muscle mass has been associated with a reduction in the amount of mitochondria in our muscle cells. Remember that our mitochondria are the power factory of our cells; they supply our cells with the energy they need to carry out their functions, and the fuel that they provide is ATP [2]. If there are less mitochondrion there will be less ATP to supply the cell with energy and there will be a drop in endurance. We can counteract this process though with cardio training; remember that cardio training will increase the amount of mitochondria in the muscle cells. So by doing your cardio you can combat the loss in mitochondria as your muscle cells grow larger.
This is just some very basic information when it comes to exercising but it is also useful. There should be a good balance of cardio and weight training in your exercise routine because the benefits you get from each one is different and beneficial to your health. Remember that doing your cardio exercise helps to strengthen your cardiopulmonary system, especially your heart, and is also good for burning fat. Doing your cardio will also help to boost your metabolism; your body will be able to burn calories more efficiently and will be able to store energy more efficiently as well. Weight training will also help to boost your metabolism, it will give you more storage space for energy, strengthen your bones, and promote lean mass and help to decrease your fat mass. Just remember you should always consult your physician and/or an exercise physiologist before you start an exercise program to make sure you are at good enough health to partake in it and to make sure there are no contraindications that would exclude you from certain exercises. This is especially important to do if you have been sedentary for a long time or know someone who has been because you never know what may have changed during the period of inactivity.
Blood Pressure
I am sure you have all heard somewhere that being overweight or obese causes high blood pressure (hypertension). Well, this is true. Being overweight is one way of getting high blood pressure. Being overweight is not the only way to attain high blood pressure though, there are other ways as well: high salt diet, genetics, sleep apnea (pause in breathing during sleep), insulin resistance, and environmental factors. All of these, except genetics, can be attributed to our lifestyle and the decisions we make. But what really is blood pressure, and how do our bodies maintain and control it, and why do our decisions make such a difference?
Have you ever wondered what your blood pressure actually is? Well it is a pressure that is created when the left ventricle of your heart contracts (like your bicep in your arm); it is a pressure that pushes the blood out of your heart and into your body. The pressure is strongest in your arteries and the weakest in your veins. Your arteries carry the blood away from your heart and have strong muscular walls while the veins carry the blood back to the heart. There are a few factors that determine your blood pressure: blood volume, cardiac output, resistance to flow (viscosity), and blood distribution. Here is a little bit of each:
Blood volume - it is logical to think that if we have more blood our pressure will be higher. Think of a balloon, the more you fill the balloon with water the more it expands. It expands because the increased volume of water puts pressure on the sides of the balloon and makes it expand. An example of this being a problem in our body is an aneurysm.
Cardiac output - cardiac output is defined as the amount of blood being pumped from the ventricles of the heart per minute. There are two factors that determine your cardiac output: stroke volume (SV) and heart rate (HR). If you multiply these two together you can figure out your cardiac output. Your SV is the amount of blood that is pumped out by a ventricle, and your heart rate is how many times your heart contracts; we typically measure this per minute. If your heart is pumping out more blood and pumping many times then it would make sense to think that your blood pressure would increase.
Viscosity - viscosity is resistance to flow, more or less. The thicker our blood is the more resistance there will be therefore increasing our blood pressure. Diabetes is the big concern here because high levels of sugar in our blood for prolonged periods of time (years) can cause many health problems, such as kidney failure, blindness, and loss of extremities.
Blood distribution - this has to do with resistance in our periphery (peripheral resistance). Depending on where there is blood there will be different amounts of resistance. The smaller the structure, the more the resistance and the higher the pressure.
Blood Pressure Controls
Reflexes in our body regulate our blood pressure; these take place through complicated circuits that are wired to what is called the cardiac control center in your brain stem (medulla oblongata). These reflexes respond to our cardiac output and peripheral resistance. If these go up then receptors that are in our aorta and carotid arteries (baroreceptors) send a signal to the cardiac control center, the center interprets the signal and lowers the blood pressure. If blood pressure drops then the circuit does not fire, as many signals to the cardiac center and the blood pressure should increase.
Our kidneys also help to regulate our blood pressure by regulating our water volume in the body. If our blood volume get to high then our kidneys get rid of some of the water in our urine and if our volume drops to low our kidneys secretes an enzyme called renin that goes through a series of reactions that causes vasoconstriction in the body. So think about this, if there is a massive vasoconstriction in the body, there will be more resistance. Think of a hose, you run water through it just the way it is and the water moves freely. Now if you put your hand around the hose and squeeze it you can feel the pressure increase because the sides of the hose are putting more pressure on the water. You can then feel the water move through the hose with more force, especially when you look at the end where the water comes out.
Causes of Hypertension
There are a few known causes of high blood pressure, which were listed earlier. It seems that the most prevalent causes in our society are obesity [3], high salt intake, and genetics and insulin sensitivity. All of these work together to lead us into hypertension, if we allow them, well all but genetics. Here is a little blurb on each one:
Salt - A good rule of thumb is that where salt goes water goes. In the chemical world opposites attract, unlike the dating world. Salt is positively charged and water is negatively charged so water likes salt. So if we consume high amounts of salt or cannot metabolize it well then our blood volume will be high.
Insulin sensitivity - remember that insulin is the hormone that is secreted when our blood sugar levels get too high. If our cells become sensitive to insulin then we cannot get that sugar out of the blood and it increases the viscosity of it, which raises the blood pressure. This is where we see a lot of long-term problems such as kidney and eye failure and extremities having to be amputated. High blood pressure alone damages our blood vessels, especially the smaller ones (capillaries) that supply our nerves with blood. Add that increased viscosity from high sugar levels then you really see problems, especially in the eyes and kidneys and extremities (feet and hands).
Obesity - The exact cause of obesity related hypertension alone is still not very well understood. Researchers have found that having a large amount of abdominal fat is more of a risk factor for hypertension than overall displacement of fat [3]. This means that a large amount of fat in our midsection seems to have a greater affect on our blood pressure than having a large amount of fat everywhere. The exact mechanism/s of this is still under some scrutiny though.
Combating Hypertension
Hypertension can be dealt with, prevented, and eliminated if a lifestyle change is made. According to the North American Association for the Study of Obesity by lowering your weight, changing your diet, and staying active you can drop your blood pressure; you can even lower it to the point where you would not need medications. Research has shown that cutting calories alone and physical activity/exercise alone can help us lose weight, but if you want the greatest results you would have to do both. Reducing emotional stress also helps lower your blood pressure. Try and eliminate things that really stress you out, or try to avoid situations that would really get to you. Also, eliminate excess alcohol consumption and smoking (if you do) from your life, these things really create havoc on our blood pressure.
Hopefully this will give you all a better understanding of blood pressure and why having hypertension is detrimental to our health. Having high blood pressure is a harmful condition that can cause damage to our hearts, vascular system, and other systems of the body as well. There is plenty of hope though because today there is a very good knowledge about hypertension and how we can combat it. The biggest area that health care professionals seem to agree on is making the lifestyle change. Remember that there are a number of risk factors out there for hypertension that should be avoided. This is a good website that lists many different ones:
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Reasons Exercise Lowers Blood Pressure
1. Makes our hearts bigger and stronger
2. Bigger and stronger heart = more strength to pump blood
3. Bigger heart means more blood can enter heart so more blood is pumped out with less effort
4. Lowers body weight which helps to lower blood pressure
5. Decreases sympathetic activity (slows body down)
6. Increase baroreceptor sensitivity [2]
Anaerobic vs. Aerobic Exercise
Energy, it’s a good thing to have when it comes to exercising. Energy is not only used by people who exercise but by all living organisms to sustain life. So where does this energy come from, and when we acquire it how do we use it? Well as humans we consume our energy from the food we eat and sometimes from the drinks we drink. Then after we consume the food we break it down into a more simple form so it can be absorbed by our small intestine, more specifically the intestinal villi. Our food is then absorbed into our lymph to be transported to the blood; and once the food reaches our blood it is carried to the proper location. Once the food reaches its location it is stored for further use if it is not needed right away. Keep in mind this is the overly simplified version of this, but in general, this is how our body works. Our body has many ways of making energy from many different substrates, but we are going to focus on two methods: anaerobic respiration and aerobic respiration. Both of these methods make energy but in different amounts, so that means they will influence certain types of exercise more than others; first we will focus on anaerobic type exercise.
Anaerobic
The term anaerobic means without oxygen, energy is made without the use of oxygen. During anaerobic respiration energy is made in the cytoplasm of our cells, this is the goop right inside of the cell where all our other functional parts lie in. There are two types of anaerobic pathways that we use to make energy for exercise, the ATP - CP system and glycolysis. Both of these systems are used to generate what is called adenosine tri-phosphate or ATP. Our cells use ATP to drive our cellular machinery to perform certain functions.
The ATP-PC system is used in cells that operate at a very high metabolic rate, such as the brain and muscles. This is used to regenerate ATP that is used up at a rapid rate. Glycolysis is where a single molecule of glucose is broken down to for ATP. This is a process that goes through various steps and stages while to break the glucose down and into ATP. The gross gain of ATP in this process is four, but two ATP are expended early on so the net gain of ATP is two. This process is sometimes termed inefficient because of the small amount of ATP that it yields but it is not. The amount of energy that is yielded from this process is very high, the problem is it cannot make energy for very long periods of time. Glycolysis will give us enough fuel, each person varies here, for about a good minutes worth of very intense exercise.
This process is very dominant in athletes who do sports that require short, intense bursts of activity, such as: sprinting, jumping, and weight lifting. People who are genetically made for these types of activities have what is called type II b, or slow twitch muscle fibers. Type II b muscle fibers look white like a chicken breast because they lack something called myoglobin. Myoglobin is the hemoglobin of muscle fibers, it helps the muscle fibers take in and use oxygen. Since type II b muscle fibers can’t take in much oxygen, they can’t make as much ATP as other muscle fiber types. Also, type II b muscle fibers have a lot of enzymes that are used in glycolysis.
Aerobic Exercise
The term aerobic means with oxygen, energy i.e. ATP is made with the help of oxygen. Aerobic respiration takes place in the mitochondria, also known as the powerhouse of the cell. There are two cycles involved in aerobic respiration and exercise: the Krebs cycle (TCA or citric acid cycle) and the electron transport chain (ETC). Once glycolysis is finished there is something else that is made; a molecule called pyruvate. Pyruvate is then changed into another molecule by an enzyme, called pyruvate dehydrogenase, to acetyl Co-A. This is an important step because once this takes place aerobic respiration can take place. Remember that the end product of fat metabolism is also acetyl Co-A but burning fats take more energy then carbohydrates, the same goes for amino acids.
The first step in aerobic respiration is the Krebs cycle. This cycle also only forms two ATP, but it forms other molecules that are important to initiate the next step (ETC) and they are NADH and FADH². These two molecules are what drive the aerobic respiration through to the next process; which makes the bulk of the ATP. The ETC uses NADH and FADH² to produce ATP with a structure/enzyme called ATP synthase. Once these molecules give up their hydrogen (H) this gives the ATP synthase the energy to make ATP. This process ends up making around 36-38 ATP, depending on the person.
People who are more endurance oriented are associated with this type of energy production because their muscles (type I fibers) have a lot of myoglobin in them. Type I fibers, or slow twitch fibers, are gray in color, much like a migratory birds muscles. Also, their muscles have a lot of mitochondria and enzymes to drive these processes.
Benefits
Each type of exercise can bring about different benefits for our bodies, during exercise and during rest. Here is a list of how aerobic exercise can benefit us:
1. Makes our heart bigger, stronger, and more efficient (during exercise and rest)
2. Increases the number of mitochondria in our skeletal muscle and heart
3. Increase the enzymes needed for aerobic respiration
4. Burns fat
5. Increase our metabolism
6. Tone muscles
7. Get rid of lactic acid much faster (during and after exercise)
8. Lower blood pressure
9. Lower LDLs (bad cholesterol) and raise HDLs (good cholesterol)
10. Stronger bones due to the impact
11. More energy
12. Lower the risk of chronic diseases such as: diabetes, CVD, cancer, etc.
Here are some benefits of anaerobic exercise:
1. Increase in metabolism
2. Store energy more efficiently
3. Promote lean muscle mass
4. Increase skeletal muscle strength
5. Make bones stronger
6. Help prevent or combat chronic diseases such as: osteoporosis, diabetes, etc.
7. Increase the number of enzymes needed for anaerobic respiration
References
1. Williams, Melvin H. Nutrition for Health and Fitness, 6th edition. New York: McGraw-Hill, 2002
2. Brooks, George A. Exercise Physiology: Human Bioenergetics and its Applications, 3rd edition. Mountain View: Mayfield Publishing Company 2000
3.
Also, the following Internet sources are excellent resources:
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