The purpose of this study was to compare different split resistance training routines on body composition and muscular strength in elite bodybuilders. Ten male bodybuilders (26.7 ± 2.7 years, 85.3 ± 10.4 kg) were randomly assigned into one of two resistance training groups: 4 and 6 times per week (G4× and G6×, respectively), in which the individuals trained for 4 weeks, 4 sets for each exercise performing 6–12 repetitions maximum (RM) in a pyramid fashion. Body composition was assessed by dual energy X-ray absorptiometry, muscle strength was evaluated by 1RM bench-press testing. The food intake was planned by nutritionists and offered individually throughout the duration of the experiment. Significant increases (p < .05) in fat-free mass (G4× = +4.2%, G6× = +3.5%) and muscular strength (G4× = +8.4%, G6× = +11.4%) with no group by time interaction were observed. We conclude that 4 and 6 weekly sessions frequencies of resistance training promote similar increases in fat-free mass and muscular strength in elite bodybuilders.
Alex S. Ribeiro, Brad J. Schoenfeld, Danilo R.P. Silva, Fábio L.C. Pina, Débora A. Guariglia, Marcelo Porto, Nailza Maestá, Roberto C. Burini and Edilson S. Cyrino
Katherine A. Beals and Amanda K. Hill
The purpose of this study was to examine the prevalence of disordered eating (DE), menstrual dysfunction (MD), and low bone mineral density (BMD) among US collegiate athletes (n = 112) representing 7 different sports (diving, swimming, x-country, track, tennis, field hockey, and softball) and determine differences in prevalence existed between athletes participating in lean-build (LB) and non-lean build (NLB) sports. DE and MD were assessed by a health, weight, dieting, and menstrual history questionnaire. Spinal BMD was determined via dual energy x-ray absorptiometry. Twenty-eight athletes met the criteria for DE, twenty-nine for MD, and two athletes had low BMDs (using a Z score below −2.0). Ten athletes met the criteria for two disorders (one with disordered eating and low BMD and nine with disordered eating and menstrual dysfunction), while only one athlete met the criteria for all three disorders. Using a Z score below −1.0, two additional athletes met the criteria for all three disorders and three more athletes met the criteria for a combination of two disorders. With the exception of MD, which was significantly more prevalent among LB vs. NLB sports (P = 0.053), there were no differences between the groups in the prevalence of individual disorders or combinations of disorders. These data indicate that the combined prevalence of DE, MD, and low BMD among collegiate athletes is small; however, a significant number suffer from individual disorders of the Triad.
Darren G. Candow, Natalie C. Burke, T. Smith-Palmer and Darren G. Burke
The purpose was to compare changes in lean tissue mass, strength, and myof-brillar protein catabolism resulting from combining whey protein or soy protein with resistance training. Twenty-seven untrained healthy subjects (18 female, 9 male) age 18 to 35 y were randomly assigned (double blind) to supplement with whey protein (W; 1.2 g/kg body mass whey protein + 0.3 g/kg body mass sucrose power, N = 9: 6 female, 3 male), soy protein (S; 1.2 g/kg body mass soy protein + 0.3 g/kg body mass sucrose powder, N = 9: 6 female, 3 male) or placebo (P; 1.2 g/kg body mass maltodextrine + 0.3 g/kg body mass sucrose powder, N = 9: 6 female, 3 male) for 6 wk. Before and after training, measurements were taken for lean tissue mass (dual energy X-ray absorptiometry), strength (1-RM for bench press and hack squat), and an indicator of myofbrillar protein catabolism (urinary 3-methylhistidine). Results showed that protein supplementation during resistance training, independent of source, increased lean tissue mass and strength over isocaloric placebo and resistance training (P < 0.05). We conclude that young adults who supplement with protein during a structured resistance training program experience minimal beneficial effects in lean tissue mass and strength.
Stacy D. Hunter, Mandeep S. Dhindsa, Emily Cunningham, Takashi Tarumi, Mohammed Alkatan, Nantinee Nualnim and Hirofumi Tanaka
Obesity is associated with arterial stiffening and diminished quality of life. Bikram yoga may be a feasible alternative to traditional exercise among obese individuals. Accordingly, the purpose of this study was to investigate the impact of Bikram yoga, a heated style of hatha yoga, on arterial stiffness in normal and overweight/obese adults.
Forty-three (23 normal body mass index or BMI; 20 overweight/obese) apparently healthy participants completed an 8-week Bikram yoga intervention. Body composition was estimated via dual energy x-ray absorptiometry, arterial stiffness was measured via brachialankle pulse wave velocity, and health-related quality of life was assessed via RAND 36-Item Short Form survey at baseline and at the end of the 8-week intervention.
After the intervention, brachial-ankle pulse wave velocity decreased (P < .05) in overweight/obese participants while no such changes were observed in normal BMI participants. In the quality of life measures, emotional well-being improved (P < .05) in both groups, and general health improved (P < .05) only in the normal weight BMI group.
Bikram yoga ameliorates arterial stiffness in overweight/obese adults and can positively impact quality of life regardless of BMI.
Heidi L. Petersen, C. Ted Peterson, Manju B. Reddy, Kathy B. Hanson, James H. Swain, Rick L. Sharp and D. Lee Alekel
This study determined the effect of training on body composition, dietary intake, and iron status of eumenorrheic female collegiate swimmers (n = 18) and divers (n = 6) preseason and after 16 wk of training. Athletes trained on dryland (resistance, strength, fexibility) 3 d/wk, 1.5 h/d and in-water 6 d/wk, nine, 2-h sessions per week (6400 to 10,000 kJ/d). Body-mass index (kg/m2; P = 0.05), waist and hip circumferences (P ≤ 0.0001), whole body fat mass (P = 0.0002), and percentage body fat (P ≤ 0.0001) decreased, whereas lean mass increased (P = 0.028). Using dual-energy X-ray absorptiometry, we found no change in regional lean mass, but fat decreased at the waist (P = 0.0002), hip (P = 0.0002), and thigh (P = 0.002). Energy intake (10,061 ± 3617 kJ/d) did not change, but dietary quality improved with training, as refected by increased intakes of fber (P = 0.036), iron (P = 0.015), vitamin C (P = 0.029), vitamin B-6 (P = 0.032), and fruit (P = 0.003). Iron status improved as refected by slight increases in hemoglobin (P = 0.046) and hematocrit (P = 0.014) and decreases in serum transferrin receptor (P ≤ 0.0001). Studies are needed to further evaluate body composition and iron status in relation to dietary intake in female swimmers.
Peter N. Wiebe, Cameron J. R. Blimkie, Nathalie Farpour-Lambert, Julie Briody, Damian Marsh, Allan Kemp, Chris Cowell and Robert Howman-Giles
Few studies have explored osteogenic potential of prepubertal populations. We conducted a 28-week school-based exercise trial of single-leg drop-landing exercise with 42 prepubertal girls (6 to 10 yrs) randomly assigned to control (C), low-drop (LD) or high-drop (HD) exercise groups. The latter two groups performed single-leg drop-landings (3 sessions/wk−1 and 50 landings/session−1) from 14cm(LD) and 28cm(HD) using the nondominant leg. Osteogenic responses were assessed using Dual Energy X-ray Absorptiometry (DXA). Single-leg peak ground-reaction impact forces (PGRIF) in a subsample ranged from 2.5 to 4.4 × body-weight (BW). No differences (p > .05) were observed among groups at baseline for age, stature, lean tissue mass (LTM), leisure time physical activity, or average daily calcium intake. After adjusting for covariates of body mass, fat mass and LTM, no differences were found in bone mineral measures or site-specific bone mineral density (BMD) at the hip and lower leg among exercise or control groups. Combining data from both exercise groups failed to produce differences in bone properties when compared with the control group. No changes were apparent for between-leg differences from baseline to posttraining. In contrast to some reports, our findings suggest that strictly controlled unimodal, unidirectional single-leg drop-landing exercises involving low-moderate peak ground-reaction impact forces are not osteogenic in the developing prepubertal female skeleton.
Jenna E. Heller, Joi J. Thomas, Bruce W. Hollis and D. Enette Larson-Meyer
Excess body fat or obesity is known to increase risk of poor vitamin D status in nonathletes but it is not known if this is the case in athletes. Furthermore, the reason for this association is not understood, but is thought to be due to either sequestration of the fat-soluble vitamin within adipose tissue or the effect of volume dilution related to obese individuals’ larger body size. Forty two US college athletes (24 men 18 women, 20.7 ± 1.6 years, 85.0 ± 28.7 kg, BMI = 25.7 ± 6.1 kg/m2) provided blood samples during the fall and underwent measurement of body composition via dual energy X-ray absorptiometry. Serum samples were evaluated for 25-hydroxyvitamin D (25(OH)D) concentration to assess vitamin D status using Diasorin 25(OH)D radioiodine assay. Serum 25(OH)D concentration was negatively associated with height (r = -0.45), total body mass (r = -0.57), BMI (r = -0.57), body fat percentage (r = -0.45), fat mass (r = -0.60) and fat-free mass (r = -0.51) (p < .05). These associations did not change after controlling for sex. In a linear regression mixed model, fat mass (coefficient -0.47, p = .01), but not fat-free mass (coefficient -0.18, p = .32) significantly predicted vitamin D status and explained approximately 36% of the variation in serum 25(OH)D concentration. These results suggest that athletes with a large body size and/or excess adiposity may be at higher risk for vitamin D insufficiency and deficiency. In addition, the significant association between serum 25(OH)D concentration and fat mass in the mixed model, which remained after controlling for sex, is in support of vitamin D sequestration rather than volume dilution as an explanation for such association.
Lenka Humenikova Shriver, Nancy Mulhollen Betts and Mark Edward Payton
Many wrestlers engage in chronic dieting and rapid “weight cutting” throughout the year to compete in a category below their natural weight. Such weightmanagement practices have a negative influence on their health and nutritional status, so the National Wrestling Coaches Association implemented a new weight-management program for high school wrestlers in 2006.
The purpose of this study was to determine whether seasonal changes in weight, body fat, and eating attitudes occur among high school wrestlers after the implementation of the new weight-management rule.
Fifteen high school wrestlers participated in the study. Their weight, body composition, and eating attitudes were measured preseason, in-season, and off-season. Body fat was assessed using dual-energy X-ray absorptiometry. Attitudes toward dieting, food, and body weight were assessed using the Eating Attitude Test (EAT).
No significant changes in body fat were detected from preseason to off-season. Weight increased from preseason to in-season (p < .05) and off-season (p < .05). Although the EAT score did not change significantly from preseason to offseason, 60% reported “thinking about burning up calories when exercising” during preseason, and only 40% felt that way during the season (p < .05) and 47% during off-season (p < .05).
The wrestlers experienced a significant weight gain from preseason to off-season with no significant changes in body fat. Their eating attitudes did not change significantly from preseason to off-season in this study, but further research using a large sample of high school wrestlers is warranted to confirm these findings.
John Petrizzo, Frederick J. DiMenna, Kimberly Martins, John Wygand and Robert M. Otto
To achieve the criterion appearance before competing in a physique competition, athletes undergo preparatory regimens involving high-volume intense resistance and aerobic exercise with hypocaloric energy intake. As the popularity of “drug-free” competition increases, more athletes are facing this challenge without the recuperative advantage provided by performance-enhancing drugs. Consequently, the likelihood of loss of lean body and/or bone mass is increased. The purpose of this investigation was to monitor changes in body composition for a 29-year-old self-proclaimed drug-free female figure competitor during a 32-week preparatory regimen comprising high-volume resistance and aerobic exercise with hypocaloric energy intake. We used dual-energy x-ray absorptiometry (DXA) to evaluate regional fat and bone mineral density. During the initial 22 weeks, the subject reduced energy intake and engaged in resistance (4–5 sessions/week) and aerobic (3 sessions/week) training. During the final 10 weeks, the subject increased exercise frequency to 6 (resistance) and 4 (aerobic) sessions/week while ingesting 1130–1380 kcal/day. During this 10-week period, she consumed a high quantity of protein (~55% of energy intake) and nutritional supplements. During the 32 weeks, body mass and fat mass decreased by 12% and 55%, respectively. Conversely, lean body mass increased by 1.5%, an amount that exceeded the coefficient of variation associated with DXA-derived measurement. Total bone mineral density was unchanged throughout. In summary, in preparation for a figure competition, a self-proclaimed drug-free female achieved the low body-fat percentage required for success in competition without losing lean mass or bone density by following a 32-week preparatory exercise and nutritional regimen.
Joseph M. Kindler, Hannah L. Ross, Emma M. Laing, Christopher M. Modlesky, Norman K. Pollock, Clifton A. Baile and Richard D. Lewis
Assessment of physical activity in clinical bone studies is essential. Two bone-specific physical activity scoring methods, the Bone Loading History Questionnaire (BLHQ) and Bone-Specific Physical Activity Questionnaire (BPAQ), have shown correlations with bone density and geometry, but not architecture. The purpose of this study was to determine relationships between physical activity scoring methods and bone architecture in non-Hispanic white adolescent females (N = 24; 18-19 years of age). Bone loading scores (BLHQ [hip and spine] and past BPAQ) and energy expenditure (7-day physical activity recall) were determined from respective questionnaires. Estimates of trabecular and cortical bone architecture at the nondominant radius and tibia were assessed via magnetic resonance imaging. Total body and regional areal bone mineral density (aBMD), as well as total body fat mass and fat-free soft tissue (FFST) mass were assessed via dual energy X-ray absorptiometry. Pearson’s correlations and partial correlations adjusting for height, total body fat mass, and FFST were performed. Hip BLHQ scores were correlated with midtibia cortical volume (r = .43; p = .03). Adjusted hip and spine BLHQ scores were correlated with all midtibia cortical measures (r = .50-0.58; p < .05) and distal radius apparent trabecular number (r = .46-0.53; p < .05). BPAQ scores were correlated with all midtibia cortical (r = .41-0.51; p < .05) and most aBMD (r = .47-0.53; p < .05) measures. Energy expenditure was inversely associated with femoral neck aBMD only after statistical adjustment (r = .49, p < .05). These data show that greater load-specific physical activity scores, but not energy expenditure, are indicative of greater midtibia cortical bone quality, thus supporting the utility of these instruments in musculoskeletal research.