ABSTRACT - American Society of Exercise Physiologists



Journal of Exercise PhysiologyonlineAugust 2015Volume 18 Number 4Editor-in-ChiefTommy Boone, PhD, MBAReview BoardTodd Astorino, PhDJulien Baker, PhDSteve Brock, PhDLance Dalleck, PhDEric Goulet, PhDRobert Gotshall, PhDAlexander Hutchison, PhDM. Knight-Maloney, PhDLen Kravitz, PhDJames Laskin, PhDYitAun Lim, PhDLonnie Lowery, PhDDerek Marks, PhDCristineMermier, PhDRobert Robergs, PhDChantal Vella, PhDDale Wagner, PhDFrank Wyatt, PhDBen Zhou, PhDOfficial Research Journal of the American Society of Exercise PhysiologistsISSN 1097-9751Official Research Journal of the American Society of Exercise Physiologists ISSN 1097-9751JEPonlineChronic Effect of Strength Training with Blood Flow Restriction on Muscular Strength among Women with Osteoporosis Júlio Silva1, Gabriel Rodrigues Neto1, Eduardo Freitas1, Elísio Neto1, Gilmário Batista1, M?nica Torres2, Maria do Socorro Sousa11Physical Education Graduate Program, Federal University of Paraíba (UFPB), Paraíba, PB, Brazil, 2State University of Rio de Janeiro (UERJ), Rio de Janeiro, RJ, BrazilABSTRACTSilva J, Neto GR, Freitas E, Pereira Neto E, Batista G, Torres M, Sousa MS. Chronic Effect of Strength Training with Blood Flow Restriction on Muscular Strength among Women with Osteoporosis. JEPonline 2015;18(4):33-41. The aim of this study was to analyze the chronic effect of strength training (ST) combined with blood flow restriction (BFR) on maximal dynamic strength (MDS) in osteoporotic women. Fifteen elderly women with osteoporosis, aged 62.2 ± 4.53 yrs, took part in the study. They were proportionally randomized into three groups: (a) low-intensity strength training with BFR (LI+BFR); (b) high intensity exercise (HI); and (c) control (CON). Experimental groups performed knee extensions for 12 wks, 2 times·wk-1. The CON subjects maintained their normal daily activities. They did not perform any type of exercise during the study period. The one-repetition maximum (1-RM) test was performed to assess MDS pre-test and at 6th- and 12th-wks. Outcomes showed significant increases in the MDS when the pre-test and the 12th-wk values were compared for the HI and LI+BFR groups (P<0.001; P=0.004), respectively. The ES of LI+BFR was also effective in improving MDS levels. Therefore, this method of intervention might be an effective alternative for special groups, particularly osteoporotic women.Keywords: Strength Training, Osteoporosis, Women, KaatsuINTRODUCTIONIn Brazil, it is estimated that ~10 million people suffer from osteoporosis (9). According to the World Health Organization (22), this disease is the second-largest health care problem in the world followed by cardiovascular disorders. Osteoporosis is a metabolic bone disorder characterized by decreased bone mineral density (BMD) with deterioration of the bone microarchitecture. The disorder occurs most frequently after menopause (20). Combined with the decrease in muscle mass, BMD decreases the capacity to produce strength that leads to increased skeletal fragility and fractures due to falls (13). On the other hand, strength training (ST) is an excellent treatment to increase the size and strength of the muscles to help maintain and/or increase BMD in people with osteoporosis (2). As a result, there is anticipated reduction in the risk of falls along with an increase in functional capacity (8). Thus, high-intensity ST improves the performance of daily activities among older adults and people with osteoporosis (21,28,26). The physiological mechanisms associated with high-intensity ST (≥ 70% of one-repetition maximum, 1-RM) and improvements in BMD are attributed to the stress imposed on the joints, the muscles, and the skeletal structures in which the muscles originate and insert (6). Yet, several studies show that low-intensity ST (20 to 50% of 1-RM) combined with blood flow restriction (BFR) produces similar strength and muscle mass gains without causing great stress to the joints resulting from high-intensity ST (1,11,16). This means the combination of ST with BFR may be a better alternative, especially at the beginning of the training sessions to increase muscle strength and muscle mass in older adults.The low-intensity ST with BFR method is carried out with the use of an inflatable cuff to restrict blood flow to and from the muscles. The BFR results in significant intramuscular changes and neural activity (25,27) that is associated with a rapid recruitment of type II motor units (18). These are also changes observed in high-intensity ST that are important for developing strength, increasing muscle mass, and improving functional capacity.While the benefits of performing ST with BFR among older adults without osteoporosis are already documented [e.g., increased muscle strength (10,30), improved bone markers (4,11,17), and improved hormonal response (7,23)], the purpose of this study was to analyze the chronic effect of strength training (ST) combined with BFR on maximal dynamic strength (MDS) in osteoporotic women. METHODSSubjectsFifteen osteoporotic women agreed to participate as subjects in this study. They were proportionally randomized into three groups: (a) low-intensity ST group with blood flow restriction (LI+BFR); (b) high-intensity ST group (HI); and (c) control group (CON), which was not exposed to exercise (refer to Table 1 for subject characteristics). The sample size was calculated using G*Power 3.1? software (Ausseldorf, Bundesland, Germany). Based on a post-hoc analysis, an alpha level of P≤0.05, a correlation coefficient of 0.5, and an effect size of 0.80 were used for n = 15 subjects. We found that the sample size was sufficient to provide 80.9% statistical power. To calculate the sample size, the procedures suggested by Beck were adopted (3). Table 1. Sample Characteristics.VariablesControl(n=5)HI(n=5)LI+BFR(n=5)Age (yrs)62.20 ± 4.0861.80 ± 6.0162.60 ± 4.33Height (cm) 152.96 ± 6.59 150.56 ± 4.85 151.78 ± 5.99Body Mass (kg) 58.52 ± 12 57.32 ± 8.56 63.98 ± 11.91Note: Values are expressed as the means ± standard deviations; HI = high-intensity group; LI+BFR = low-intensity group combined with blood flow restriction.Women with the following characteristics were included in the study: (a) chronological age greater than 50 yrs; (b) six months without performing lower-limb strengthening activities; and (c) previous diagnosis of osteoporosis with a T-score lower than -2.5 SD. After the study’s possible risks and benefits were explained, the subjects signed an informed consent form prepared in accordance with the Declaration of Helsinki. The study was approved by the Human Research Ethics Committee under protocol no. 100/13.InstrumentsDetermination of BFRThe BFR procedure was performed by vascular Doppler (MedPej? DV-2001, Ribeir?o Preto, State of S?o Paulo - SP, Brazil), in which the transducer was placed on the posterior tibial artery. A blood pressure cuff (18 cm in width and 80 cm in length) was secured to the thigh (inguinal fold) and inflated to the point that the auscultatory pulse of the tibial artery was interrupted (15). The tourniquet pressure used during the training protocol was set as 80% of the pressure required for complete BFR in the resting state (15). The cuff was deflated between the series. The mean pressure used throughout the exercise protocol was 104.20 ± 7.88 mm Hg.Maximum Strength Measure (1-RM)The MDS (1-RM) was determined following the recommendations of the American Society of Exercise Physiologists (5) and was performed using a leg extension machine (Body Fitness, Brazil) unilaterally (right lower limb). The sample subjects were instructed not to perform physical activities or strenuous efforts for at least 24 hrs prior to the tests. To warm up, a series of 5 to 10 repetitions of knee extensions were performed on the same machine on which the test was performed, with a load of 40% of the perceived 1-RM. After 1-min of rest, the subjects performed a second series of 3 to 5 repetitions with 60 to 80% of the perceived 1-RM load. Subsequently, the subjects tried to perform a maximum repetition. The load was measured regardless of the goal being achieved or not. The subjects had at most five attempts with 5-min intervals between them to allow for measurement of the 1-RM. In case the 1-RM could not be measured in these five attempts, this process was repeated after 72 hrs. No pause was allowed between the concentric and the eccentric phase of a repetition or between repetitions. The maximum strength was evaluated pre-test and at the 6th-wk and the 12th- wk.ProceduresST ProgramThe ST program lasted 12 wks. It was designed with two weekly sessions separated by a 48-hr interval (totaling 24 sessions). The exercise used was unilateral knee extension (right leg). The experimental groups performed a 3-min warm-up on a stationary bicycle. The HI group performed the exercise with four series until concentric failure with a load corresponding to 80% of 1-RM and a 2-min rest interval between series (mean of 8.0 ± 2.01 repetitions per series; Figure 1A). The LI+BFR group performed four series, until concentric failure, with a load corresponding to 30% of 1-RM, a 30-sec rest interval between series (mean of 7.0 ± 3.38 repetitions per series), and the BFR using an inflatable cuff (Figure 1B). The CON subjects maintained their normal daily activities without a commitment to any type of physical exercise or strenuous activity involving the lower limbs throughout the study’s intervention period and until the post-test was performed.Statistical AnalysesThe descriptive results are expressed as the means ± standard deviations. The effect size was used to determine the magnitude of changes between the assessed time-points (24), and the percentage variation (Δ%) was used to express possible differences in muscle strength between the first and the third evaluations (post-test). Analysis of variance of repeated measures [3 x 3; protocols (BRF vs. HI vs. CON) x time (pre-test vs. 6th-wk vs. 12th-wk)] followed by the Bonferroni’s post hoc test were used to evaluate the effects of exercise for all dependent variables. The significance level adopted was P≤0.05. No assumption of the use of the parametric statistics was violated. All analyses were performed in the statistical software Statistical Package for the Social Sciences (SPSS) version 20.0 (SPSS Inc., Chicago, IL, USA).RESULTSIn the intergroup comparison of the MDS, significant differences were observed at the 6th-wk when evaluating LI+BFR vs.CON groups (P=0.004) and at the 12th-wk when evaluating LI+BFR vs. CON and HI vs. CON groups (P=0.004 and P=0.017, respectively) (Table 2). In the intragroup analysis, the HI group exhibited a significant difference when comparing pre- vs. 6th-wk, pre- vs. 12th-wk and 6th-wk vs. 12th-wk (P<0.001, ES = 1.44, ?%= 18.35; P<0.001, ES= 2.77, ?% = 34.5; P=0.002, ES = 1.39, ?%= 13.65, respectively). For the LI+BFR group, there was a significant difference when comparing pre- vs. 6th-wk and pre- vs. 12th-wk (P=0.006, ES = 5.71, ?%= 0.30; P=0.004, ES = 0.63, ?%= 10.59). The CON group did not exhibit significant differences between the three assessed time-points (P>0.05). Table 2. Comparative Analysis of Maximum Dynamic Strength (1-RM) between the Study Groups. RMControlHILI+BFRPre-27.98 ± 3.7427.78 ± 3.4535.85 ± 6.726th- WK27.94 ± 3.76 32.88 ± 3.21* 37.90 ± 5.71*12th-WK27.83 ± 3.58 37.37 ± 4.58* 40.10 ± 7.39*Note: *Significant differences between pre- and 6th-wk, pre- and 12th-wk and 6th-wk and 12th-wk (P<0.05); HI = high-intensity group; LI+BFR = low-intensity group combined with blood flow restriction.DISCUSSIONThis study analyzed the chronic effect of ST combined with BFR on the MDS of women with osteoporosis. The data from this study show significant increases in MDS in the two assessment time-points after the intervention program started in both experimental groups, but with no significant differences between them. These results corroborate those obtained by Mosti et al. (19), who observed increased maximum strength levels after a high-intensity intervention period (85 to 90% of 1-RM) over 12 wks. The same authors also observed improved BMD levels. In the study by Mosti et al. (19), the exercises were performed 3 times·wk-1, while in the present study, the exercises were performed 2 times·wk-1 without BFR. In the present study, considering that significant increases in MDS were observed with and without BFR, we can infer that performing the exercises 2 times·wk-1 with and without BFR seems to be sufficient to observe increased MDS in the analyzed periods and in the studied population. Thus, ST with BFR may be an alternative for improving MDS levels provided that a high volume of exercise is performed (greater than or equal to 2 times·wk-1).The effects of exercise with BFR for increasing muscle strength (11,29) are well known. This improvement is justified by increased muscle hypertrophy and neuromuscular adaptations (29). Several studies have also observed increased muscle strength when using ST with BFR in older adults (10,12,30). However, to the best of our knowledge, the present study is the first to study the effects of ST with BFR in a population of subjects with osteoporosis.Based on studies by Karabulut et al. (10) and Yasuda et al. (30), it seems that performing ST with BFR promotes increased muscle strength in older adults whether or not they have osteoporosis. When analyzing the studies by Karabulut et al. (10) and Yasuda et al. (30) and comparing them to the present study, one observes that even when exercises are performed unilaterally, strength gains may be similar to those obtained when exercises are performed bilaterally (i.e., ST with BFR can be performed both unilaterally and bilaterally to increase the strength of older adults). Thus, we speculate that there was an increase in muscle strength levels for the LI with BFR and HI groups and that a consequent increase in MDS would occur. This result would be a counterpoint for the assertion that high-intensity and high-impact ST would be the only effective way of increasing levels of strength, hypertrophy, and gain in the formation or maintenance of bone mass (21,26,28).Several studies have observed positive effects of ST with BFR on bone markers (4,11,17). Although ST with BFR has shown positive effects for bone metabolism, and its contribution for the recovery of bone trauma has been reported (17), it is not yet clear how this training affects bone metabolism. In a study conducted with a population of elderly men (11) that used the knee extension exercise with BFR, positive responses were observed in osteoblast activity and muscle strength. Similarly, Kim et al. (14) reported positive increases in both bone turnover markers and muscle cross-sectional area in older adults who trained with and without BFR. However, subjects who performed high-intensity training exhibited the greatest gains and showed improved bone turnover, based on higher responses of the bone anabolic marker for that type of exercise. Similarly, Bemben et al. (4) observed that, after a session of ST with BFR, the analyses of bone markers of absorption and reabsorption indicated an increase in osteoblast activity and a decrease in osteoclast activity. Thus, ST with BFR seems to be effective for developing bone tissue because it indicates a positive response in bone rehabilitation (14). Based on the above and on the articles mentioned previously, it seems that similarly to high-intensity ST, ST with BFR can improve bone markers.Thus, based on the abovementioned findings and the data from the present study, ST performed in combination with BFR is effective for increasing MDS in the elderly population with osteoporosis. Because improvements in bone markers were observed in other studies with the use of BFR, it is reasonable to expect that this method will be an alternative intervention in this population. However, further studies are needed to assess the efficacy of using ST with BFR in the BMD of elderly populations with osteoporosis. Therefore, we recommend that high- and low-intensity training with BFR be used to prevent and control osteoporosis.CONCLUSIONSLow-intensity ST combined with BFR seems to be effective for increasing MDS in elderly women with osteoporosis. Thus, this method seems to be an effective alternative for special population groups, especially in women with osteoporosis.Address for correspondence: Neto GR, MD, Department of Physical Education - Associate Graduate Program in Physical Education UPE / UFPB, Federal University of Paraíba, University City, Research Center for Human Movement Sciences, Kinanthropometry Laboratory, Room 06 and 08. Castelo Branco. Jo?o Pessoa – 58051-900, Brazil. / Phone: 55 083 9612-2726 E-mail: gabrielrodrigues_1988@REFERENCESAbe T, Fujita S, Nakajima T, Ozaki H, Sakamaki M, Ishii N. Effects of low-intensity cycle training with restricted leg blood flow on thigh muscle volume and VO2 max in young men. J Sci Med Sport. 2010;9:452-458.Aveiro MC, Navega MT, Granito RN, Rennó ACM, Oishi J. The effects of a physical exercise program on the balance, on the quadriceps muscle strength, and on the quality of life in osteoporotic women. Rev Bras Cienc Mov. 2004;12:33-38.Beck TW. The importance of a priori sample size estimation in strength and conditioning research. J Strength Cond Res. 2013;27:2323-2337.?Bembem DA, Palmer IJ, Abe T, Sato Y, Bembem MG.Effects of a single bout of low intensity KAATSU resistance training on markers of bone turnover in young men. Int J Kaatsu Training Res. 2007;3:21-26. Brown LE, Weir JP. ASEP procedures recommendation I: Accurate assessment of muscular strength and power. J Exerc Physiol. 2001;4:1-21.Farup J, Tue k, Sorensen H, Dalgas U, Moller AB, Vestergaard PF, Vissing K. Muscle morphological and strength adaptations to endurance vs. resistance training. J Strength Cond Res. 2012;26:398-407.Fry CS, Glynn EL, Drummond MJ, Timmerman KL, Fujita S, Abe T, Ahanani S, Volpi E. Rasmussen BB. Blood flow restriction exercise stimulates mTORC1 signaling and muscle protein synthesis in older men. J Appl Physiol. 2010;108:1199-209. Garber CE, Blissmer B, Deschenes MR, Franklin BA, Lamonte MJ, Lee IM. Swain DP. American College of Sports Medicine position stand Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: Guidance for prescribing exercise. Med Sci Sports Exerc. 2011;43:1334-1359. Hartard M, Haber P, Ilieva D, Preisinger E, Seidl G. Systematic strength training as a model of therapeutic intervention – A controlled trial in postmenopausal women with osteopenia. Am J Phys Med Rehabil. 1996;75:21-28.Karabulut M, Abe T, Sato Y, Bembem MG. The effects of low-intensity resistance training with vascular restriction on leg muscle strength in older men. Eur J Appl Physiol. 2010;108:147-155. Karabulut M, Bembem DA, Sherk VD, Anderson MA, Abe T, Bembem MG. Effects of high-intensity resistance training and low-intensity resistance training with vascular restriction on bone markers in older men. Eur J Appl Physiol. 2011;111:1659-1667. Karabulut M, Sherk VD, Bembem DA, Bembem MG. Inflammation marker, damage marker and anabolic hormone responses to resistance training with vascular restriction in older males. Clin Physiol Funct Imaging. 2013;33:393-399. Kell R, Bell G, Quinney A. Musculoskeletal fitness, health outcomes and quality of life. Sports Med. 2001;31:863-873.Kim S, Sherk VD, Bembem MG, Bembem DA. Effects of short term low intensity resistance training with blood flow restriction on bone markers and muscle cross-sectional area in young men. Int J Exerc Sci. 2012;5:136-147.Laurentino G, Ugrinowitsch C, Aoki SM, Soares AG, Tricoli V. Strength training with blood flow restriction diminishes myostatin gene expression. Med Sci Sports Exerc. 2012;44:406-412. Loenneke JP, Pujol TJ. The use of occlusion training to produce muscle hypertrophy. Strength Cond J. 2009;31:77-84.Loenneke JP, Kaellin CY, Wilson JM, Andersen JC. Rehabilitation of an osteochondral fracture using blood flow restricted exercise: A case review. J BodywMovTher. 2013;17:42–45. Moore DR, Burgomaster KA, Schofield LM, Gibala MJ, Sale DG, Philipes SM. Neuromuscular adaptations in human muscle following low intensity resistance training with vascular occlusion. Eur J Appl Physiol. 2004;92:399-406. Mosti MP, Kaehler N, Stunes AK, Hoff J, Syversen U. Maximal strength training in postmenopausal women with osteoporosis or osteopenia. J Strength Cond Res. 2013;27: 2879-o P, Soares A, Urbanetz AA, Ferreira AEM, Amaral B, Chahade W. Brazilian Consensus of Osteoporosis. Rev Bras Reumatol. 2002;42.Novaes G, Novaes J, Vila?a-alves J, Fernandes HM. Furtado H, Mendes R, Reis VM. Effects of 24 weeks of strength training or hydrogymnastics on bone mineral density in postmenopausal women. J Sports Med Phys Fitness. 2013;53:51-56.World Health Organization. Preliminary report and recommendations of an experts commission of the World Health Organization on an overall strategy for osteoporosis. Rev Esp Enfer Metab Oseas. 2000;9:78-83.Patterson SD, Legate M, Nimmo MA, Ferguson RA. Circulating hormone and cytokine response to low-load resistance training with blood flow restriction in older men. Eur J Appl Physiol. 2013;113:713–719. Rhea MR. Determining the magnitude of treatment effects in strength training research through the use of the effect size. J Strength Cond Res. 2004;18:918-920.Sato Y. The history and future of KAATSU Training. Int J Kaatsu Training Res. 2005;1:1-5. Silva CM, Gurj?o ALD, Ferreira L, Gobbi LTB, Gobbi S. Effect of resistance training, prescribed by zone of maximum repetitions, on the muscular strength and body composition in older women. Rev Bras Cineantropom e Desempenho Hum. 2006;8:39-45.Suga T, Okita K, Morita N, yokota T, Takada S, Tsutsui H. Intramuscular metabolism during low-intensity resistance exercise with blood flow restriction. J Appl Physiol. 2009;106:1119-1124. Vale RGS, Barreto ACG, Novaes JS, Dantas EHM. Effect of resistive training on the maximum strength,flexibility and functional autonomy of elderly woman. Rev Bras Cineantropom Desempenho Hum. 2006;8:52-58. Yasuda T, Loenneke JP, Thiebaud RS, Abe T. Effects of blood flow restricted low-intensity concentric or eccentric training on muscle size and strength. PloS one. 2012;7:528-543. Yasuda T, Fukumura K, Fukuda T, Uchida Y, Lida H, Meguro M, Nakajima T. Muscle size and arterial stiffness after blood flow-restricted low-intensity resistance training in older adults. Scan J Med Sci Sports. 2013;1–8.DisclaimerThe opinions expressed in JEPonline are those of the authors and are not attributable to JEPonline, the editorial staff or the ASEP organization. ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download