The effect of 10 wk of protein-supplement timing on strength, power, and body composition was examined in 33 resistance-trained men. Participants were randomly assigned to a protein supplement either provided in the morning and evening (n = 13) or provided immediately before and immediately after workouts (n = 13). In addition, 7 participants agreed to serve as a control group and did not use any protein or other nutritional supplement. During each testing session participants were assessed for strength (one-repetition-maximum [1RM] bench press and squat), power (5 repetitions performed at 80% of 1RM in both the bench press and the squat), and body composition. A significant main effect for all 3 groups in strength improvement was seen in 1RM bench press (120.6 ± 20.5 kg vs. 125.4 ± 16.7 at Week 0 and Week 10 testing, respectively) and 1RM squat (154.5 ± 28.4 kg vs. 169.0 ± 25.5 at Week 0 and Week 10 testing, respectively). However, no significant between-groups interactions were seen in 1RM squat or 1RM bench press. Significant main effects were also seen in both upper and lower body peak and mean power, but no significant differences were seen between groups. No changes in body mass or percent body fat were seen in any of the groups. Results indicate that the time of protein-supplement ingestion in resistance-trained athletes during a 10-wk training program does not provide any added benefit to strength, power, or body-composition changes.
Jay R. Hoffman, Nicholas A. Ratamess, Christopher P. Tranchina, Stefanie L. Rashti, Jie Kang and Avery D. Faigenbaum
Kimberly M. White, Stephanie J. Bauer, Kristopher K. Hartz and Monika Baldridge
Resistance training is an effective method to decrease body fat (BF) and increase fat-free mass (FFM) and fat oxidation (FO). Dairy foods containing calcium and vitamin D might enhance these benefits. This study investigated the combined effects of habitual yogurt consumption and resistance training on body composition and metabolism.
Untrained women (N = 35) participated in an 8-wk resistance-training program. The yogurt group (Y) consumed 3 servings of yogurt containing vitamin D per day, and the control groups maintained their baseline lowdairy-calcium diet. Postexercise, Y consumed 1 of the 3 servings/d fat-free yogurt, the protein group consumed an isocaloric product without calcium or vitamin D, and the carbohydrate group consumed an isocaloric product without protein. Strength, body composition, fasted resting metabolic rate (RMR) and FO, and serum 25-hydroxyvitamin D were measured before and after training.
Calories (kcal · kg−1 · d−1) and protein (g · kg−1 · d−1) significantly increased from baseline for Y. FFM increased (main effect p = .002) and %BF decreased (main effect .02) for all groups with training, but Group × Time interactions were not observed. RMR and FO did not change with training for any group.
Habitual consumption of yogurt during resistance training did not augment changes in body composition compared with a low-dairy diet. Y decreased %BF as a result of training, however, even with increased calorie consumption.
Ricardo A. Tanhoffer, Aldre I. P. Tanhoffer, Jacqueline Raymond, Andrew P. Hills and Glen M Davis
The objective of this study was to verify the long-term effects of exercise on energy expenditure and body composition in individuals with spinal cord injury (SCI), as very little information is available on this population under free-living conditions.
Free-living energy expenditure and body composition using doubly labeled water (DLW) was measured in 13 individuals with SCI, subdivided in 2 groups: (1) sedentary (SED; N = 7) and (2) regularly engaged in any exercise program, for at least 150 min·wk−1 (EXE; N = 6).
The total daily energy expenditure (TDEE) was significantly higher in the EXE group (33 ± 4.5 kcal·kg−1·day−1) if compared with SED group (27 ± 4.3 kcal·kg−1·day−1). The percentage of body fat was significantly higher in SED group than in EXE group (38 ± 6% and 28 ± 9%).
Our findings revealed that, despite the severity of SCI, the actual ACSM’s guidelines for weight management for healthy adults exercise could significantly increase TDEE and BMR and improve body composition in individuals who regularly perform exercise. However, the EXE group still showed a high percentage of body fat, suggesting that a more specific approach might be considered (ie, increased intensity or volume, or combining with a diet program).
Kevin Till, Ben Jones, John O’Hara, Matthew Barlow, Amy Brightmore, Matthew Lees and Karen Hind
To compare the body size and 3-compartment body composition between academy and senior professional rugby league players using dual-energy X-ray absorptiometry (DXA).
Academy (age 18.1 ± 1.1 y, n = 34) and senior (age 26.2 ± 4.6 y, n = 63) rugby league players received 1 total-body DXA scan. Height, body mass, and body-fat percentage alongside total and regional fat mass, lean mass, and bone mineral content (BMC) were compared. Independent t tests with Cohen d effect sizes and multivariate analysis of covariance (MANCOVA), controlling for height and body mass, with partial eta-squared (η2) effect sizes, were used to compare total and regional body composition.
Senior players were taller (183.2 ± 5.8 vs 179.2 ± 5.7 cm, P = .001, d = 0.70) and heavier (96.5 ± 9.3 vs 86.5 ± 9.0 kg, P < .001, d = 1.09) with lower body-fat percentage (16.3 ± 3.7 vs 18.0 ± 3.7%, P = .032, d = 0.46) than academy players. MANCOVA identified significant overall main effects for total and regional body composition between academy and senior players. Senior players had lower total fat mass (P < .001, η 2 = 0.15), greater total lean mass (P < .001, η 2 = 0.14), and greater total BMC (P = .001, η 2 = 0.12) than academy players. For regional sites, academy players had significantly greater fat mass at the legs (P < .001, η 2 = 0.29) than senior players.
The lower age, height, body mass, and BMC of academy players suggest that these players are still developing musculoskeletal characteristics. Gradual increases in lean mass and BMC while controlling fat mass is an important consideration for practitioners working with academy rugby league players, especially in the lower body.
Fredric L. Goss, Robert J. Robertson, John Dube, Jason Rutkowski, Joseph Andreacci, Brooke Lenz, Julie Ranalli and Krisi Frazee
This investigation examined the impact of a cycle ergometry exercise test (CET) on body composition determined using leg-to-leg bioelectrical impedance analysis (BIA; Tanita Model TPF-305). Fifty three children (25 males, 28 females) aged 10-12 yr participated. BIA measures of body fat (BF) were obtained immediately before and within five min of a multistage CET administered to assess peak oxygen consumption. Correlations (P = 0.01) of 0.99 were noted between the pre and post CET measures of BF. A systematic difference was not found in BIA measures obtained before and after CET. BF decreased by 0.4 and 1.2% following CET in the male and female subjects, respectively.
Francis X. Short and Joseph P. Winnick
This manuscript examines the validity and reliability of the tests used to measure body composition in the Brockport Physical Fitness Test. More specifically, information is provided on skinfold measures and body mass index and their applicability to youngsters with mental retardation and mild limitations in fitness, visual impairment (blindness), cerebral palsy, spinal cord injury, or congenital anomalies or amputations. The rationale for criterion-referenced standards for these test items for youngsters with these disabilities is provided along with some data on attainability of those standards. Possible ideas for future research are recommended.
Joan M. Eckerson, Dona J. Housh, Terry J. Housh and Glen O. Johnson
The purpose of this investigation was to determine the changes in body composition, isokinetic strength, and muscular power in high school wrestlers across a season of competition. Wrestlers were measured (preseason and postseason) for body composition and isokinetic peak torque for flexion and extension of the dominant forearm and leg. Each subject also completed Wingate anaerobic tests to determine changes in mean power and peak power (PP) of the legs. The results indicated that body weight (BW), fat weight, and percent fat decreased (p < .002) across the wrestling season. PP and absolute peak torque for forearm and leg extension (LE) at 30°·s−1; forearm flexion (FF) at 30, 180, and 300°·s−1; and leg flexion (LF) at 180 and 300°·s−1 were significantly (p < .05) lower postseason. Relative peak torque (adjusted for BW) decreased (p < .05) across the season for LE at 30°·s−1 as well as FF and LF at 180°·s−1. Therefore, changes in BW were not associated with functional advantages in terms of strength or muscular power.
Marc Bonis, Mark Loftin, Richard Speaker and Anthony Kontos
The purpose of the study was to investigate the seasonal relationship of athletic amenorrhea and body composition in elite, adolescent, cross-country runners. The participants consisted of 28 female adolescent cross-country runners (mean age ± SD = 15.4 ± 1.5 years); 17 eumenorrheics and 11 amenorrheics. The participants’ body composition was measured pre- and postseason using dual-energy X-ray Absorptiometer (DXA). The eumenorrheics’ postseason BMD was significantly greater than the amenorrheics’ postseason BMD (F(1,54) = 16.22, p < .05, partial η 2 = .231). The eumenorrheics’ postseason bodyweight (F(1,54) = 7.65, p < .05, partial η 2 = .124), BF (F(1,54) = 8.56, p < .05, partial η 2 = .137), and BMC (F(1,54) = 8.52, p < .05, partial η 2 = .136) were significantly greater than the amenorrheic subgroup. There was also a significant seasonal increase in BMD (t(27) = –4.01, p < .05) for the overall group and the eumenorrheic subgroup (t(16) = –3.90, p < .05). Bodyweight best predicted BMD (F(1,26) = 46.434, p < .05, R2 = .641). In the study, athletic amenorrhea was highly associated with lower levels of BMD in the participants, and crosscountry running was highly associated with increased BMD.
Mary A. Steinhardt and Debra J. Macklem
The use of skinfold measurements is a popular method to determine percentage of body fat because of its relative simplicity. Although attention has been paid to its technical accuracy and validity, less consideration has been given to the psychological impact on participants. The purpose of this study was to determine students’ (N = 128) reactions to having skinfold measurements taken in university physical education classes. Skinfold measurements were taken, and a questionnaire administered during the 2nd and 13th weeks of the semester. The questionnaire was used to assess (a) if students were self-conscious or uncomfortable during the measurements, (b) if knowing percent body fat motivated students to exercise, and (c) if the procedure should remain a standard part of class. Descriptive results indicated most students agreed that percent fat measurement was a valuable part of the class. On the pretest, after controlling for sex, regression analysis revealed that percent fat significantly predicted feelings of self-consciousness (R 2 =.08; β = .36) and motivation to exercise (R 2 = .07; β.24). On the posttest, percent fat again predicted feelings of self-consciousness (R 2 = .21; β = .58) but did not predict motivation to exercise. Also, students with greater percent fat felt the body composition assessment should be optional (R 2 = .08; β = −.36). Although results of this study support body composition assessment in university health-related activity classes, the need for sensitivity to the emotional needs and privacy of individuals is recommended.
Maija Hassinen, Pirjo Komulainen, Timo A. Lakka, Sari B. Väisänen and Rainer Rauramaa
The epidemic of sedentary lifestyle and obesity increases the risk of disability with aging. We studied the relationships of body composition, physical activity, and muscular fitness with balance and walking ability.
Men and women, age 70 to 74 y (n = 146), were randomly selected from the Finnish population register. Body composition [body weight, body-mass index (BMI), waist circumference], physical activity (questionnaire), muscular fitness (hand-grip strength), balance (commonly used field tests), and walking ability (20 m walking test) were assessed.
BMI (r = –0.287, P < 0.001), waist circumference (r = –0.260, P = 0.002), physical activity (r = 0.206, P = 0.013), and hand-grip strength (r = 0.244, P = 0.003) correlated with balance. BMI (r = 0.330, P < 0.001), waist circumference (r = 0.237, P = 0.004), physical activity (r = –0.252, P = 0.002), and hand-grip strength (r = –0.307, P < 0.001) also correlated with walking time.
Overweight and central obesity as well as low muscular fitness associate with impaired balance and walking ability in the elderly.