. The measuring tape was placed between the last palpable rib and the top of the iliac crest for waist circumference and around the widest part of the buttock for hip circumference ( World Health Organization, 2008 ). Body composition Percentage of body fat and percentage of lean body mass (%LBM) were
Sheng H. Kioh, Sumaiyah Mat, Shahrul B. Kamaruzzaman, Fatimah Ibrahim, Mas S. Mokhtar, Noran N. Hairi, Robert G. Cumming, Phyo K. Myint and Maw P. Tan
Michael J. Davies, Gail P. Dalsky and Paul M. Vanderburgh
This study employed allometry to scale maximal oxygen uptake (V̇O2 max) by body mass (BM) and lean body mass (LBM) in healthy older men. Ratio standards (ml · kg−1 · min−1) derived by dividing absolute V̇O2 max (L · min−1) by BM or LBM often fail to control for the body size variable. The subjects were 73 older men (mean ± SD: age = 69.7 ± 4.3 yrs, BM = 80.2 ± 9.6 kg, height = 174.1 ± 6.9 cm). V̇O2 max was assessed on a treadmill with the modified Balke protocol (V̇O2 max = 2.2 ± 0.4 L · min−1). Body fat (27.7 ± 6.4%) was assessed with dual energy x-ray absorptiometry. Allometry applied to BM and V̇O2 max determined the BM exponent to be 0.43, suggesting that heavier older men are being penalized when ratio standards are used. Allometric scaling applied to LBM revealed the LBM exponent to be 1.05 (not different from the ratio standard exponent of 1.0). These data suggest that the use of ratio standards to evaluate aerobic fitness in older men penalized fatter older men but not those with higher LBM.
Arny A. Ferrando and Nancy R. Green
The effect of boron supplementation was investigated in 19 male bodybuilders, ages 20–27 years. Ten were given a 2.5-mg boron supplement while 9 were given a placebo every day for 7 weeks. Plasma total and free testosterone, plasma boron, lean body mass, and strength measurements were determined on Days 1 and 49 of the study. Plasma boron values were significantly (p<0.05) different as the experimental group increased from (±SD) 20.1 ±7.7 ppb pretest to 32.6 ±27.6 ppb posttest, while the control group mean decreased from 15.1 ±14.4 ppb pretest to 6.3 ±5.5 ppb posttest. Analysis of variance indicated no significant effect of boron supplementation on any of the dependent variables. Both groups demonstrated significant increases in total testosterone, lean body mass, 1-RM squat, and 1-RM bench press. The findings suggest that 7 weeks of bodybuilding can increase total testosterone, lean body mass, and strength in lesser trained bodybuilders, and that boron supplementation had no effect on these measures.
Mark Messina, Heidi Lynch, Jared M. Dickinson and Katharine E. Reed
each group and a comparison of change between groups (χ 2 ) are shown. LBM = lean body mass; RET = resistance exercise training; SMD = standard mean difference; CI = confidence interval. Figure 5 —Forest plot showing the effect of protein source supplementation (other proteins vs. soy) combined with
Claudia Ridel Juzwiak, Olga Maria Silverio Amancio, Maria Sylvia Souza Vitalle, Vera Lúcia Szejnfeld and Marcelo Medeiros Pinheiro
In this prospective, cross-sectional study male adolescent tennis players (44) and nonathletic controls (32) were evaluated to determine the effects of physical activity, dietary nutrient intakes, sexual maturation, and body composition on bone-mineral density (BMD). Dietary nutrient intakes and physical activity expenditure were estimated by 4-d diaries. Total body composition, bone-mineral content (BMC), and BMD (L1–L4, femur, and nondominant forearm) were assessed by dual-energy X-ray absorptiometry. Tennis players had significantly greater lean body mass (mean [SEM] 50.6 [1.6] kg vs. 45.1 [1.7] kg, p = .022), trochanter BMD (1.0 [0.02] g/cm2 vs. 0.9 [0.03] g/cm2, p = .032), and dominant forearm BMC (173.7 [7.4] g vs. 146.5 [9.3] g) but lower BMD in the nondominant forearm (0.7 [0.02] g/cm2 vs. 0.8 [0.03] g/cm2, p = .028). Daily average calcium intake was below the recommendation in both groups. No correlation was found between BMD and calcium intake and exercise. Lean body mass was the best predictor of BMD and BMC for both tennis players and controls (R 2 = .825, .628, and .693 for L1–L4, total femur, and nondominant forearm, respectively). Based on these results the authors conclude that lean body mass is the best predictor of BMD and BMC for both tennis players and others. Tennis exerts a site-specific effect, and training should focus on ways minimize this effect. Although calcium intake showed no effect on BMD, nutrition education for young athletes should focus on promoting a balanced diet, providing energy and nutrients in adequate amounts.
Felipe Fossati Reichert, Jonathan Charles Kingdom Wells, Ulf Ekelund, Ana Maria Baptista Menezes, Cesar Gomes Victora and Pedro C. Hallal
Physical activity may influence both fat and lean body mass. This study investigated the association between physical activity in children between the ages of 11 and 13 years and both fat and lean mass.
A subsample of the 1993 Pelotas (Brazil) Birth Cohort was visited in 2004–2005 and 2006–2007. Physical activity was estimated through standardized questionnaires. Body composition (ie, fat and lean mass) was measured using deuterium dilution. Those with moderate-to-vigorous activity greater than 420 min/wk were classified as active, and physical activity trajectory was defined as being above or below the cutoff at each visit.
Four hundred eighty-eight adolescents (51.8% boys) were evaluated. The mean difference in fat mass in boys and girls who reported ≥ 420 min/wk of physical activity in both visits compared with those who were consistently inactive was –4.8 kg (P ≤ .001). There was an inverse association between physical activity and fat mass among boys in both crude and confounder-adjusted analyses, whereas for girls, the association was evident only in the crude analysis. There was no significant association between physical activity and lean mass.
Physical activity may contribute to tackling the growing epidemic of adolescent obesity in low- and middle-income countries.
Gary J. Farkas, Marika A. Pitot and David R. Gater Jr.
Following a spinal cord injury (SCI), alterations in body composition, limited mobility and physical activity, anabolic deficiencies, and sympathetic nervous system blunting lead to an elevated risk of morbidity and mortality ( Farkas & Gater, 2017 ). The loss of metabolically active lean body mass
Leigh Gabel, Heather M. Macdonald, Lindsay Nettlefold and Heather A. McKay
lean body mass was 0.3% in adults (University of British Columbia Bone Health Research Group, unpublished data). Maturity To control for well-known maturational differences between adolescent boys and girls of the same chronological age, we determined age at peak height velocity (APHV, years) as an
Aline C. Tritto, Salomão Bueno, Rosa M.P. Rodrigues, Bruno Gualano, Hamilton Roschel and Guilherme G. Artioli
). Training status of participants appears to be a major determinant of the responsiveness to HMB supplementation. Studies with untrained individuals have reported positive effects on strength and lean body mass (LBM; Jówko et al., 2001 ; Nissen et al., 1996 ; Vukovich et al., 2001 ). By contrast, those
Megan Colletto and Nancy Rodriguez
warranted. Based on skeletal muscle indices (kg lean body mass/height [m 2 ]), approximately 71% of males and 42% of females older than 65 years are moderately sarcopenic ( Janssen, 2006 ). The development of sarcopenia is multifactorial ( Janssen, 2011 ) and managing sarcopenia is vital to the reduction of