The improvement in walking speed induced by resistance training is associated with increased muscular strength but not skeletal muscle mass in older women

Objective: The purpose of the present study was to analyze whether improvements in fast walking speed induced by resistance training (RT) are associated with changes in body composition, muscle quality, and muscular strength in older women. Methods: Twenty-three healthy older women (69.6?±?6.4 years, 64.95?±?12.9?kg, 1.55?±?0.07?m, 27.06?±?4.6?kg/m²) performed a RT program for 8 weeks consisting of 8 exercises for the whole body, 3 sets of 10–15 repetitions maximum, 3 times a week. Anthropometric, body composition (fat-free mass [FFM], skeletal muscle mass [SMM], legs lean soft tissue [LLST], fat mass), knee extension muscular strength (KE1RM), muscle quality index (MQI [KE1RM/LLST]), and 10-meter walking test (10-MWT) were performed before and after the intervention. Results: Significant (P?<?.05) changes were observed from pre- to post-training for FFM (+1.6%), MQI (+7.2%), SMM (+2.4%), LLST (+1.8%), KE1RM (+8.6%), fat mass (?1.4%), and time to perform 10-MWT (?3.7%). The percentage change in 10-MWT was significantly associated with percentage change in MQI (r?=??0.46, P?=?.04) and KE1RM (r?=??0.45, P?=?.04), however not associated percentage of changes in SMM (r?=?0.01, P?=?.97), LLST (r?=??0.22, P?=?.33), and body fat (r?=?0.10, P?=?.66). Conclusion: We conclude that the improvement in the 10-MWT after an 8-week RT program is associated with increases in lower limb muscular strength and muscle quality, but not with muscle mass or body fat changes in older women.     

Yearly Changes in the Body Composition and Muscular Strength of High School Wrestlers

Abstract

The purpose of this investigation was to determine the yearly changes in body composition as well as absolute and relative isokinetic forearm flexion and extension strength of high school wrestlers. Evaluations of body composition (underwater weighing) were performed on 27 high school wrestlers prior to three consecutive seasons. In addition, isokinetic forearm flexion and extension strength values at 180°/s (Cybex II) were available for 20 of the subjects. The mean ages at the times of laboratory testing were 15.5 (± .5), 16.5 (± .5), and 17.5 (± .5) years. Repeated measures ANOVA or ANCOVA with Tukey post-hoc comparisons were used to locate significant (p<.05) differences across age for height, body weight, relative fat, body density, fat weight, fat-free weight, absolute muscular strength, and muscular strength covaried for body weight and fat-free weight. There were yearly increases in all variables except fat weight, forearm flexion covaried for fat-free weight and forearm extension covaried for fat-free weight. The results of this study indicated that the improved wrestling performance and the increase in weight classification which normally occurs during high school are, in part, a function of yearly changes in body composition and muscular strength.     

Substrate oxidation during incremental arm and leg exercise in men and women matched for ventilatory threshold

The aim of this study was to determine the variations in substrate utilization between men and women matched for ventilatory threshold (Tvent) during incremental arm cranking and leg cycling exercise at 70, 85, 100 and 115% of the mode-specific Tvent. Recreationally active men (n=12) and women (n=10) with similar values for percentage of peak oxygen consumption at Tvent participated in the study. Ventilatory equivalence, excess CO2 and modified V-slope methods were used concurrently to determine Tvent. The participants performed 5 min of exercise at each of 70, 85, 100 and 115% Tvent during both arm cranking and leg cycling exercise. The females were tested during the early follicular phase for all trials. A two-way mixed-design analysis of variance was performed to test for differences between the sexes. When carbohydrate and fat oxidation were expressed relative to total fat-free mass, carbohydrate oxidation during arm cranking and leg cycling was significantly higher in men than women at each percentage of Tvent. In contrast, women showed significantly higher fat oxidation across intensities during both arm cranking and leg cycling. Our results suggest that when substrate utilization is expressed relative to total fat-free mass, women appear to maintain a higher rate of fat and lower rate of carbohydrate oxidation than men during both incremental arm cranking and leg cycling exercise relative to Tvent.     

The Importance of Strength,Speed, and Body Size for Team Success in Women's Intercollegiate Volleyball

Various anthropometric, strength, and speed variables were obtained on 180 intercollegiate women volleyball players who participated in a regional round-robin tournament. The purpose of the study was to determine the factors underlying the motor performance of the women and then determine if there was any relationship between the factors and team success. Factor analysis of the measured variables showed that the variables could be dimensioned as body size, speed/fat, and strength. Multiple discriminant analysis showed that the teams were significantly different on the factors of strength and speed/fat. Team centroids were plotted in two-dimensional discriminant space, and this graphic representation showed that the stronger, faster, and leaner teams were the most successful in tournament play. The results showed that the basic factors of speed/fat and strength were related to team success. Multiple discriminant analysis helped to identify the two most important individual variables for team success. Upper body strength and fat weight were identified as most important in differentiating between players of the most and least successful teams.     

Body Fatness and Performance Differences between Men and Women

The purpose of this study was to determine the extent to which the mean difference in performance between men and women on selected physical performance tests was related to the sex difference in body fatness. Percent total body fat (% fat) estimated from skinfold thickness measures and performances on the modified pull-up, vertical jump, 50-yard dash, and 12-minute-run tests were measured on 55 male and 55 female college students. Males had significantly less fat and performed significantly better than females on each of the performance tests. Mean differences were 8.2% fat, 20.0 modified pull-ups, 20.8 cm on the vertical jump, 1.3 seconds on the 50-yard dash, and 590 m on the 12-minute run. Linear regression equations predicting performance scores from % fat within the groups of men and women indicated that if body fatness in men and women were similar, performance differences would be reduced, on the average, by 7 modified pull-ups, 4 cm on the vertical jump, .5 seconds on the 50–yard dash, and 146 m on the 12-minute run. These expected changes in performance were 36%, 19%, 38%, and 25% of the mean sex difference in performance on the four physical performance tests, respectively. It was concluded that greater body fatness is one characteristic that partly explains why women, on the average, do not perform as well as men on strenuous tasks requiring movement of the body weight. The sex-specific difference in body fatness should be one factor considered in establishing separate occupational and athletic performance expectations for men and women.     

Anthropometric characteristics as discriminators of body-building success.

A total of 36 non-elite male body builders were observed at the time of competition. Their mean physical characteristics (+/- S.D.) were: age, 24.6 +/- 4.8 years; height, 174.4 +/- 6.7 cm; bodyweight, 80.3 +/- 11.0 kg. Their body composition values were: percentage body fat, 9.3 +/- 1.6%; fat-free mass, 72.8 +/- 9.8 kg. The mean somatotype for all subjects was: endomorphy, 2.3 +/- 0.6; mesomorphy, 6.2 +/- 0.9; ectomorphy, 1.2 +/- 0.6. The body proportions (cm) included: biacromial diameter/bi-iliac diameter, 1.463 +/- 0.132; torso length/height, 0.468 +/- 0.018; chest circumference/abdominal circumference, 1.345 +/- 0.059. The body builders in the present study were younger, had lower bodyweights, lower fat-free mass, lower mesomorphy ratings, smaller circumferences, and smaller skeletal dimensions than elite body builders reported in the scientific literature. When the body builders in the present study were divided into successful and unsuccessful groups based on actual competition results, a multiple-discriminant analysis found that biacromial diameter/bi-iliac diameter, torso length/height, chest circumference/abdominal circumference, percentage body fat, height, and bodyweight accounted for 80.6% of the explained variance. These data indicate that the success of a body builder can be accounted for in large part by easily obtained physical variables.     

Anthropometric profiles of elite older triathletes in the Ironman Brazil compared with those of young Portuguese triathletes and older Brazilians

The objective of this study was to describe the anthropometric profiles of elite older triathletes participating in the 2009 Ironman Brazil and to compare their somatotype, anthropometric and body composition characteristics with those of elite young triathletes and older non-athletes. The sample consisted of 64 males, divided into three groups: (1) older triathletes (n = 17), (2) young triathletes (n = 24), and (3) older non-athletes (n = 23). Somatotype was analysed according to the Carter and Heath ( 1990 ) method. Body mass index, sum of four skinfolds, percentage body fat, body fat mass, and fat-free mass were also estimated. Older non-athletes had higher endomorphy, sum of four skinfolds, fat percentage, and body fat mass than the athletes. Older athletes who participated in the Ironman and elite young triathletes had higher fat-free mass than older non-athletes. Older triathletes and older non-athletes were considered mainly endomorphic mesomorphs and young triathletes mainly ectomorphic mesomorphs. The findings that characterize the anthropometric profile of athletes in this sports modality could be used as a reference.     

Effects of Aerobic Dance on Physical Work Capacity,Cardiovascular Function and Body Composition of Middle-Aged Women

Abstract

The purpose of this study was to determine the effects of aerobic dance on physical work capacity, cardiovascular function and body composition of young middle-aged women. Maximal oxygen uptake ([Vdot]O ₂ max), heart rate during submaximal treadmill walking, resting heart rate and blood pressure, and body composition were determined before and after a 10-week aerobic dance conditioning program in 28 women (18 experimental and 10 control), aged 25 to 44 years. During the 10-week treatment period, the experimental subjects participated in 45 min of aerobic dance at 70–85% of the heart rate reserve, 3 days · week ^–1,whereas the control group did not participate in any regular strenuous physical activity. Changes in the experimental group were significantly greater than in the control group for [Vdot]O ₂ max expressed in 1 · min ^–1 or relative to body weight or fat-free weight (5 to 7% vs. – 5 to – 8%), time on a continuous grade-incremented walking treadmill test (16% vs. 1%), heart rate during submaximal stages of the treadmill test (– 9% vs. 1%) and resting heart rate (– 8% vs. 2%). Resting systolic and diastolic blood pressure; body weight; percent fat, fat weight, and fat-free weight estimated using underwater weighing; sum of seven skinfolds; and sum of seven circumferences did not change significantly in either group. It was concluded that aerobic dance performed 30–45 min, 3 days · week ^–1 for 10 weeks significantly improves physical work capacity and cardiovascular function, but without dietary control, does not alter body composition in sedentary middle-aged women.     

Development and Validation of Body Composition: Prediction Equations for the Elderly

The purpose of this study was to develop and cross-validate anthropometric body composition equations for the elderly (i.e., ≥ 65 years old). This was undertaken due to a lack of accurate and reliable body composition equations for the elderly. One-hundred fifty male (n = 75) and female (n = 75; mean age = 70 years, SD = 3.71 years) elderly were randomly assigned to either an equation development sample (n = 50) or an equation validation sample (n = 25), respectively. The male and female development and validation sample groups, respectively, were joined to make combined development (n = 100) and validation (n = 50) samples. Hydrodensitometry was used to determine participant body density, percent fat, fat-free mass, and fat weight for use as the criterion variables by which prediction equations could be developed and validated. The equations presented are for the prediction of body density [body density = 1.0554 + .0142 (gender) + .0267 (height) - .00022 (midaxillary) - .00086 (hip circumference)], percent fat [% fat = .1688 (body mass index) + .542 (hip circumference) -.1639 (weight) -5.7033 (gender) -7.9498], fat-free mass [fat-free mass = 30.3769 + 8.0108 (height) + .824 (weight) - .1355 (suprailiac) - .5419 (hip circumference)], and fat weight [fat weight = .2449 (weight) + .5218 (hip circumference) - .076 (thigh circumference) - 4.0299 (gender) - 37.8619]. The equations provided estimates that were not statistically different from the hydrostatically determined criterion variables but were statisfically different from estimates derived from other published "elderly" body composition equations.     

A comparison of men's and women's strength to body mass ratio and varus/valgus knee angle during jump landings

The purpose of this investigation was to compare valgus/varus knee angles during various jumps and lower body strength between males and females relative to body mass. Seventeen recreationally active females (age: 21.94 ± 2.59 years; height: 1.67 ± 0.05 m; mass: 64.42 ± 8.39 kg; percent body fat: 26.89 ± 6.26%; squat one-repetition maximum: 66.18 ± 19.47 kg; squat to body mass ratio: 1.03 ± 0.28) and 13 recreationally active males (age: 21.69 ± 1.65 years; height: 1.77 ± 0.07 m; mass: 72.39 ± 9.23 kg; percent body fat: 13.15 ± 5.18%; squat one-repetition maximum: 115.77 ± 30.40 kg; squat to body mass ratio: 1.59 ± 0.31) performed a one-repetition maximum in the squat and three of each of the following jumps: countermovement jump, 30 cm drop jump, 45 cm drop jump, and 60 cm drop jump. Knee angles were analysed using videography and body composition was analysed by dual-energy X-ray absorptiometry to allow for squat to body mass ratio and squat to fat free mass ratio to be calculated. Significant differences (P ≤ 0.05) were found between male and female one-repetition maximum, male and female squat to body mass ratio, and male and female squat to fat free mass ratio. Significant differences were found between male and female varus/valgus knee positions during maximum flexion of the right and left leg in the countermovement jump, drop jump from 30 cm, drop jump from 45 cm, and drop jump from 60 cm. Correlations between varus/valgus knee angles and squat to body mass ratio for all jumps displayed moderate, non-significant relationships (countermovement jump: r = 0.445; drop jump from 30 cm: r = 0.448; drop jump from 45 cm: r = 0.449; drop jump from 60 cm: r = 0.439). In conclusion, males and females have significantly different lower body strength and varus/valgus knee position when landing from jumps.     

Body composition differences by age and playing standard in male rugby union and rugby league: A systematic review and meta-analysis

ABSTRACT

This systematic review and meta-analysis aimed to determine differences in body compositionn between playing standard and age in male rugby union and rugby league athletes. The MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines for design, implementation, and reporting were followed. Studies were required to be in male rugby union or league and have body composition as the primary or secondary outcome. Data was required to be presented separately for positional groups and body composition presented as whole-body. A systematic search was performed in PubMed, Cochrane Library, MEDLINE, SPORTDiscus, and CINHAHL via EBSCOhost. 57 studies were included for meta-analysis. Results highlighted significantly higher fat-free mass in senior elite than senior sub-elite or junior elite athletes for all RU and RL forwards. Small and non-significant differences were found in fat mass between rugby union playing standards and age categories. Rugby league senior elite forwards had less fat mass than junior elite forwards. Practitioners should prioritise training and nutritional strategies that maximise fat-free mass development, especially in junior elite cohorts.     

Prediction of fat and fat-free mass in male athletes using dual X-ray absorptiometry as the reference method

The ability of bioelectrical impedance analysis and anthropometry to predict fat mass and fat-free mass was compared in a sample of 82 male athletes from a wide variety of sports, using dual-energy X-ray absorptiometry (DXA) as the reference method. The percent fat measured by DXA was 10.9+/-4.9% (mean +/- s), and fat mass was predicted with a standard error of the estimate of 1.7 kg for skinfolds and 2.8 kg for bioelectrical impedance analysis (P < 0.001). Fat-free mass was predicted with a standard error of the estimate of 1.7 kg for anthropometry and 2.6 kg for bioelectrical impedance analysis (P < 0.001). Regression of various individual skinfolds and summed skinfolds, to examine the effect of skinfold selection combinations by stepwise regression, produced an optimal fat mass prediction using the thigh and abdominal skinfold sites, and an optimal fat-free mass prediction using the thigh, abdominal and supra-ilium sites. These results suggest that anthropometry offers a better way of assessing body composition in athletes than bioelectrical impedance analysis. Applying the derived equations to a separate sample of 24 athletes predicted fat and fat-free mass with a total error of 2.3 kg (2.9%) and 2.2 kg (2.7%), respectively. Combining the samples introduced more heterogeneity into the sample (n = 106), and the optimal prediction of fat mass used six skinfolds in producing a similar standard error of the estimate (1.7 kg), although this explained a further 4% of the variation in DXA-derived fat. Fat-free mass was predicted best from four skinfolds, although the standard error of the estimate and coefficient of determination were unchanged.     

Prediction of fat and fat-free mass in male athletes using dual X-ray absorptiometry as the reference method

The ability of bioelectrical impedance analysis and anthropometry to predict fat mass and fat-free mass was compared in a sample of 82 male athletes from a wide variety of sports, using dual-energy X-ray absorptiometry (DXA) as the reference method. The percent fat measured by DXA was 10.9 - 4.9% (mean - s ), and fat mass was predicted with a standard error of the estimate of 1.7 kg for skinfolds and 2.8 kg for bioelectrical impedance analysis (P?0.001). Fat-free mass was predicted with a standard error of the estimate of 1.7 kg for anthropometry and 2.6 kg for bioelectrical impedance analysis (P?0.001). Regression of various individual skinfolds and summed skinfolds, to examine the eff ect of skinfold selection combinations by stepwise regression, produced an optimal fat mass prediction using the thigh and abdominal skinfold sites, and an optimal fat-free mass prediction using the thigh, abdominal and supra-ilium sites. These results suggest that anthropometry off ers a better way of assessing body composition in athletes than bioelectrical impedance analysis. Applying the derived equations to a separate sample of 24 athletes predicted fat and fat-free mass with a total error of 2.3 kg (2.9%) and 2.2 kg (2.7%), respectively. Combining the samples introduced more heterogeneity into the sample (n=106), and the optimal prediction of fat mass used six skinfolds in producing a similar standard error of the estimate (1.7 kg), although this explained a further 4% of the variation in DXA-derived fat. Fat-free mass was predicted best from four skinfolds, although the standard error of the estimate and coefficient of determination were unchanged.     

8周HIIT对男子赛艇公开级运动员血红蛋白和身体成分影响的研究

目的探讨8周高强度间歇训练(High Intensity Interval Training,HIIT)对男子赛艇公开级运动员血红蛋白和身体成分的影响。方法某省16名男子赛艇公开级运动员作为研究对象,采取随机抽样的方式分成对照组和高强度间歇组(HIIT组),每组各8例。连续8周对照组采用一般日常训练,HIIT组增加高强度间歇训练。比较训练前后两组血红蛋白和身体成分指标变化情况。结果 HIIT组8名队员训练前后血红蛋白水平有显著提高(P<0.05),对照组不显著(P>0.05);体重和脂肪百分比含量下降,对照组显著(p<0.05),HIIT组极显著(p<0.01);而瘦体重和去脂体重,HIIT组有显著增加(p<0.05),对照组变化不明显(p>0.05)。结论 8周HIIT训练能明显提高赛艇男子公开级运动员血红蛋白水平,并显著降低体脂,增加瘦体重和去脂体重。     

The accuracy and precision of DXA for assessing body composition in team sport athletes

Abstract

This study determined the precision of pencil and fan beam dual-energy X-ray absorptiometry (DXA) devices for assessing body composition in professional Australian Football players. Thirty-six professional Australian Football players, in two groups (fan DXA, N = 22; pencil DXA, N = 25), underwent two consecutive DXA scans. A whole body phantom with known values for fat mass, bone mineral content and fat-free soft tissue mass was also used to validate each DXA device. Additionally, the criterion phantom was scanned 20 times by each DXA to assess reliability. Test–retest reliability of DXA anthropometric measures were derived from repeated fan and pencil DXA scans. Fat-free soft tissue mass and bone mineral content from both DXA units showed strong correlations with, and trivial differences to, the criterion phantom values. Fat mass from both DXA showed moderate correlations with criterion measures (pencil: r = 0.64; fan: r = 0.67) and moderate differences with the criterion value. The limits of agreement were similar for both fan beam DXA and pencil beam DXA (fan: fat-free soft tissue mass = ?1650 ± 179 g, fat mass = ?357 ± 316 g, bone mineral content = 289 ± 122 g; pencil: fat-free soft tissue mass = ?1701 ± 257 g, fat mass = ?359 ± 326 g, bone mineral content = 177 ± 117 g). DXA also showed excellent precision for bone mineral content (coefficient of variation (%CV) fan = 0.6%; pencil = 1.5%) and fat-free soft tissue mass (%CV fan = 0.3%; pencil = 0.5%) and acceptable reliability for fat measures (%CV fan: fat mass = 2.5%, percent body fat = 2.5%; pencil: fat mass = 5.9%, percent body fat = 5.7%). Both DXA provide precise measures of fat-free soft tissue mass and bone mineral content in lean Australian Football players. DXA-derived fat-free soft tissue mass and bone mineral content are suitable for assessing body composition in lean team sport athletes.     

Substrate oxidation during incremental arm and leg exercise in men and women matched for ventilatory threshold

Abstract

The aim of this study was to determine the variations in substrate utilization between men and women matched for ventilatory threshold (T _vent) during incremental arm cranking and leg cycling exercise at 70, 85, 100 and 115% of the mode-specific T _vent. Recreationally active men (n = 12) and women (n = 10) with similar values for percentage of peak oxygen consumption at T _vent participated in the study. Ventilatory equivalence, excess CO₂ and modified V-slope methods were used concurrently to determine T _vent. The participants performed 5 min of exercise at each of 70, 85, 100 and 115% T _vent during both arm cranking and leg cycling exercise. The females were tested during the early follicular phase for all trials. A two-way mixed-design analysis of variance was performed to test for differences between the sexes. When carbohydrate and fat oxidation were expressed relative to total fat-free mass, carbohydrate oxidation during arm cranking and leg cycling was significantly higher in men than women at each percentage of T _vent. In contrast, women showed significantly higher fat oxidation across intensities during both arm cranking and leg cycling. Our results suggest that when substrate utilization is expressed relative to total fat-free mass, women appear to maintain a higher rate of fat and lower rate of carbohydrate oxidation than men during both incremental arm cranking and leg cycling exercise relative to T _vent.     

Gender Differences in Strength

The purpose of this study was to examine gender differences in upper and lower body strength as a function of lean body weight and the distribution of muscle and subcutaneous fat in the upper and lower limbs. The subjects were 103 physically active men (n = 48) and women (n = 55). The peak torques produced during shoulder flexion (SF) and knee extension (KE) were used as measures of upper body and lower body strength, respectively. Flexed arm girth, thigh girth, triceps skinfold, and thigh skinfold were used to estimate the distribution of muscle and subcutaneous fat in the limbs. Results of the MANOVA revealed that the overall strength of men was significantly greater than that of women. Results of MANCOVA indicated that the SF and KE strength of women and men did not differ significantly when differences in lean body weight, arm girth, thigh girth, triceps skinfold and thigh skinfold were statistically controlled. High levels of SF and KE strength were associated with a high lean body weight and a large arm girth. Results of the multiple regression analysis indicated that for men a substantial portion of the variance in both SF and KE strength was explained by lean body weight alone; whereas strength variations in women were explained more adequately by including limb variables along with lean body weight. Within the limitations of this study, it was concluded that gender differences in upper and lower body strength are a function of differences in lean body weight and the distribution of muscle and subcutaneous fat in the body segments. Upper body strength is relatively more important than lower body strength in characterizing the gender difference in strength.     

Growth and body composition in Brazilian female rhythmic gymnastics athletes

Abstract

The aim was to analyse the physical growth and body composition of rhythmic gymnastics athletes relative to their level of somatic maturation. This was a cross-sectional study of 136 athletes on 23 teams from Brazil. Mass, standing height and sitting height were measured. Fat-free and fat masses, body fat percentages and ages of the predicted peak height velocity (PHV) were calculated. The z scores for mass were negative during all ages according to both WHO and Brazilian references, and that for standing height were also negative for all ages according to WHO reference but only until 12 years old according to Brazilian reference. The mean age of the predicted PHV was 12.1 years. The mean mass, standing and sitting heights, body fat percentage, fat-free mass and fat mass increased significantly until 4 to 5 years after the age of the PHV. Menarche was reached in only 26% of these athletes and mean age was 13.2 years. The mass was below the national reference standards, and the standing height was below only for the international reference, but they also had late recovery of mass and standing height during puberty. In conclusion, these athletes had a potential to gain mass and standing height several years after PHV, indicating late maturation.     

热量限制结合导引运动对中心性肥胖的临床效果

目的：辟谷是包含热量限制、导引运动等元素的中国传统养生方法,本研究借鉴辟谷将热量限制与导引运动结合应用于中心性肥胖患者,以观察其临床疗效并探讨其可行性和安全性。方法：招募23名中心性肥胖受试者进行为期7天的综合干预,观测受试者干预前后体重、腰围、体重指数（BMI）、身体成分及生理生化指标的变化。结果：综合干预后受试者的体重、BMI、腰围、体脂量均非常显著性降低（P<0.01）,但是骨骼肌、无脂体重显著减少（P<0.05）。血糖显著降低（P<0.01）,心率、血压、甘油三酯、总胆固醇未显示统计学差异。肝、肾功能指标无明显异常,主观反馈无明显不良反应。结论：热量限制结合导引运动有效帮助中心性肥胖患者缓解肥胖、控制体重,但同时存在无脂体重流失的风险。这为进一步完善干预方案和深入机理研究提供了理论参考与实践基础。     

Effect of a randomised 12-week resistance training programme on muscular strength,cross-sectional area and muscle quality in women having undergone Roux-en-Y gastric bypass

The purpose of this study was to examine the effect of a 12-week resistance training programme on fat-free mass (FFM), muscle cross-sectional area, muscular strength and muscle quality in women who underwent Roux-en-Y gastric bypass surgery. Participants were 16 women (mean age = 44.9 ± 10.2 years) from bariatric surgical groups who were randomly assigned into either a control or an intervention group. Air displacement plethysmography measured FFM and magnetic resonance imaging measured quadriceps muscle cross-sectional area and whole thigh muscle cross-sectional area. Muscular strength and quality was assessed using an estimated 1-Repetition Maximum assessment. All measurements were collected twice, at baseline and at a 12-week follow-up. There were significantly greater improvements in leg press strength (mean differences = 55.4%, P < 0.001, Cohen’s d = 2.4), leg extension strength (mean differences = 18.0%, P = 0.014, Cohen’s d = 0.86) and leg press muscle quality (mean differences = 54.5%, P < 0.001, Cohen’s d = 1.9) in the intervention group compared to the control group following the resistance training programme. The resistance training intervention significantly improved muscular strength and quality; however, it did not illicit changes in FFM or muscle cross-sectional area in women who underwent Roux-en-Y gastric bypass surgery.