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Exercise. Understanding Human Biology: Body CompositionI. INTRODUCTIONYour weight, height, and bone structure make up your body composition. Using height andweight tables, it is possible to determine the ‘ideal’ weight of a person. For example, two people may be the same height and weight, but one may be overweight, while the other is "normal". The difference is in the amount of Fat that each person carries as part of his or her body composition. Total body weight is made up of the person’s lean body weight (muscle) plus the fat weight and bone. A. Height and weight TablesHeight and weight tables are easy to use and have been produced by averaging the informationfrom many different people. The ease of use of these tables is, however, balanced by the fact that these tables do not differentiate between the weight attributed to bone, muscle, and fat in each body. The tables do, however, group individuals into one of 3 categories: small-framed,medium-framed, and large-Framed, which helps to distinguish differences in bone structure. Aperson Found to be 10% over the ideal designated weight is said to be overweight, while 10%under the value is an indication of being underweight.B. PROCEDURETo determine your Frame size, grip your right wrist with your left hand so that your thumb andmiddle ?nger touch each other. (1) If the two digits overlap by more than half an inch, you are small-framed. (2) If the two digits overlap by less than half an inch, you are said to be medium-framed,and (3) if the thumb and ?nger do not touch, then this is designated large- framed.Try this with your wrist and write your designation. ____________________________________Using the weight tables supplied by your instructor, what is your ideal weight range?_________C. Prediction Equations.It is possible to predict with some degree of accuracy, the ideal weight of a person by carryingout measurements of the skeleton. In these measurements, bone size, rather than height andweight is measured.D. PROCEDUREUsing a centimeter measuring tape ask your partner to measure your wrist, Forearm, ankle andcalf, at their largest circumference.Your Measurement (cm)WristForearmAnkleCalfTotal Table 1. Body Measurements.Divide the total by 17.07 if you are male, or by 16.89 if you are Female. This gives yourdividend. Now square the dividend (multiply the number by itself)Multiply the squared dividend by your height in centimeters. (Use the table that your instructorgave you to calculate your height in centimeters.)Then multiply the product by 0.0111 This will give you your "ideal weight" in kilograms.TotalDivided SquaredDividedSquared xHeight (cm)Multiply by0.011 = IdealWeight (kg)Your DividendTable 2. Determination of ideal weight.If you want to know your ‘ideal weight, in pounds, then multiply the weight by 2.2.__________Are you within your ideal weight (10% either side of this number)?_______________________E. Skinfold MeasurementsThe skinfold test gives an accurate determination of the amount of body fat a person has. Fat islocated immediately below the surface of the skin and is proportional to total body Fat. Once atrained individual obtains accurate readings, these readings may be converted to percent bodyfat, which may be used to determine a person's ideal body weight.F. What is your body mass index (BMI)?Body Mass Index (BMI) is a number calculated from a person's weight and height. BMI is a fairly reliable indicator of body fatness for most people. BMI does not measure body fat directly, but research has shown that BMI correlates to direct measures of body fat, such as underwater weighing and dual energy x-ray absorptiometry (DXA). BMI can be considered an alternative for direct measures of body fat. Additionally, BMI is an inexpensive and easy-to-perform method of screening for weight categories that may lead to health problems.How is BMI used?BMI is used as a screening tool to identify possible weight problems for adults. However, BMI is not a diagnostic tool. For example, a person may have a high BMI. However, to determine if excess weight is a health risk, a healthcare provider would need to perform further assessments. These assessments might include skinfold thickness measurements, evaluations of diet, physical activity, family history, and other appropriate health screenings. Calculation of BMI. BMI is calculated the same way for both adults and children. The calculation is based on the following formulas:Measurement UnitsFormula and CalculationKilograms and meters (or centimeters) BMI = weight (kg) / [height (m)]2 With the metric system, the formula for BMI is weight in kilograms divided by height in meters squared. Since height is commonly measured in centimeters, divide height in centimeters by 100 to obtain height in meters.Example: Weight = 68 kg, Height = 165 cm (1.65 m)Calculation: 68 ÷ (1.65)2 = 24.98Pounds and inchesBMI = Weight (pounds) ÷ Height (inches)2 x 703Calculate BMI by dividing weight in pounds (lbs) by height in inches (in) squared and multiplying by a conversion factor of 703.Example: Weight = 150 lbs, Height = 5'5" (65")Calculation: [150 ÷ (65)2] x 703 = 24.96Interpretation of BMI for adultsFor adults 20 years old and older, BMI is interpreted using standard weight status categories that are the same for all ages and for both men and women. For children and teens, on the other hand, the interpretation of BMI is both age- and sex-specific. For more information about interpretation for children and teens, visit Child and Teen BMI Calculator. The standard weight status categories associated with BMI ranges for adults are shown in the following table. BMIWeight StatusBelow 18.5Underweight18.5 – 24.9Normal25.0 – 29.9Overweight30.0 and AboveObeseFor example, here are the weight ranges, the corresponding BMI ranges, and the weight status categories for a sample height. HeightWeight RangeBMIWeight Status5' 9"124 lbs or lessBelow 18.5Underweight125 lbs to 168 lbs18.5 to 24.9Normal169 lbs to 202 lbs25.0 to 29.9Overweight203 lbs or more30 or higherObeseWHAT IS YOUR BODY MASS INDEX (BMI)?x 703BMI = Weight (pounds) Height (inches)?Height Weight in Pounds (lb)?1001101201301401501601701801902002102202302402504' 4"2628.631.233.836.43941.644.246.849.45254.657.259.862.4654' 6"24.126.528.931.333.836.238.64143.445.848.250.65355.457.960.34' 8"22.424.726.929.131.433.635.938.140.442.644.847.149.351.653.8564' 10"20.92325.127.229.331.333.435.537.639.741.843.94648.150.252.25'19.521.523.425.427.329.331.233.235.237.139.1414344.946.948.85' 2"18.320.121.923.825.627.429.331.132.934.736.638.440.242.143.945.75' 4"17.218.920.622.32425.727.529.230.932.634.33637.839.541.242.95' 6"16.117.819.42122.624.225.827.42930.732.333.935.537.138.740.35' 8"15.216.718.219.821.322.824.325.827.428.930.431.933.43536.5385' 10"14.315.817.218.720.121.52324.425.827.328.730.131.63334.435.96'13.614.916.317.61920.321.723.124.425.827.128.529.831.232.533.96' 2"12.814.115.416.71819.320.521.823.124.425.72728.229.530.832.16' 4"12.213.414.615.81718.319.520.721.923.124.325.626.82829.230.46' 6"11.612.713.91516.217.318.519.620.82223.124.325.426.627.728.96' 8"1112.113.214.315.416.517.618.719.820.92223.124.225.326.427.56' 10"10.511.512.513.614.615.716.717.818.819.920.922232425.126.1LEGEND:UnderweightNormal WeightOverweightObeseII. In this section, we will determine the amount of body fat on you and your partner’s body, using the skinfold test and calipers. A. PROCEDURE1. Your instructor will illustrate the correct way to measure skinfolds using the calipers or fat-O-meter. 2. Using skinfold calipers or fat-O-meter, measure the skin on the right side of your partner's body. Using your fore?nger and thumb, grasp and lift the fold of skin and carefully pinch it. Pinch and lift the skin several times to ensure that no muscle is trapped in the fold. Hold the skin ?rmly, and put the calipers below the thumb and finger. Be careful, do not let go of the skinfold. Measure the Fold of skin accurately, and record it below. Repeat the measurement 3 times to increase your accuracy, then take the average of the 3 readings. B. Measure:1) Tricep - (women only) this is measured on the back of the upper right arm, halfway between the elbow and the tip of the shoulder, parallel to the long axis of the body. Measure this while the arm is hanging loosely by the side of the body.2) Ilium. Hip (men and women)- Fold the skin diagonally just above the top of the right hipbone on an imaginary line that would divide the body into front and back halves.3) Abdomen. (men and women) fold the skin vertically 1" to skin fold with caliper or fat-O-meter the right of the belly button.4) Chest. (men only) fold the skin diagonally, halfway between the right nipple and the right armpit.5) Axilla. side (men only) Fold the skin vertically, level with the right nipple, on an imaginary line that would divide the body into front and back halves.Skin FoldReading123AverageChestAbdominalThighTotal of all skin fold measurement averages Table 1 Skin fold readings for men.Percent Fat Estimates for Men _______________ . Skin FoldReading123AverageTricepsSuprailiumThighTotal of all skin fold measurement averages Table 2 Skin fold readings for women.Percent Fat Estimates for women ____________ .Skin FoldReading123AverageBicepsTricepsSubscapularSuprailiumTotal of all skin fold measurement averages Table 3 Skin fold readings for men. Percent Fat Estimates for men ______________ .Skin FoldReading123AverageBicepsTricepsSubscapularSuprailiumTotal of all skin fold measurement averages Table 4 Skin fold readings for women.Percent Fat Estimates for women ____________ .C. Your instructor will show you how to use these tables. This is the approximate percentage body fat you have (remember, an expert would be more accurate than you would be).Your % body fat = _______________.1. In a healthy body, it is suggested that adult males should have l6% or less body Fat, and adult females should have 23% or less body fat. At no time should the body fat of a male go below 5%, nor a females body fat go below 10%. If this does occur, severe medical problems can occur, and a doctor should be consulted.2. A strong athlete, such as a runner or swimmer, who has trained and eaten correctly and is in good physical condition usually has between 10-12% body Fat. A football player may have as high as 19- 20% body fat.3. An individual is thought to be obese when he/she has over 20% (male) or 30% (female) body fat.[Note: In doing this experiment, remember that you are not trained in these techniques and that your estimation is arbitrary and can, and will, vary with many different factors!!!!]III. Calculating BMI and Waist-to-Hip RatioIn this experiment, you will measure your body mass index (BMI) and waist-to-hip ratio (WTH). It has been shown recently that body weight and build may give anindication of Cardio Vascular Disease Factors. So BMI and WTH data may be an indication as to how healthy you are.A. PROCEDURE1. Determine your weight in pounds_______________________________.2. Multiply this value by 700_____________________________________.3. Divide this number by your height in inches _______________________.4. Divide this number by your height in inches again___________________.5. This value is your BMI________________________________________.6. Below are the BMI values and how they relate to heart disease:Values 25 or less: very low to low riskValues 25-30: low to moderate risk30 or more: moderate to high riskB. Now determine your WTH ratio.l. Measure your waist (relaxed state) in inches____________________________.2. Measure your hips at their widest point in inches________________________.3. Divide the waist measurement by the hip measurement____________________.Women with a ratio 0.8 or less have a low risk of cardiovascular disease.Men with a ratio of 0.95 or less have a low risk of cardiovascular disease.C. These values determine the LIKELY risk of cardiovascular disease, but, as mentioned above, many other Factors play a part in your risk, such as smoking, blood pressure, physical activity level, frequency, and duration. ................
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