Effects of protein versus mixed macronutrient supplementation on total energy intake (TEI) and protein intake during an ad libitum diet were examined. Trained males undertook two, 2-week dietary interventions which were randomized, double blinded, and separated by 2 weeks. These were high-protein supplementation (HP: 1034.5 kJ energy, 29.6 g protein, 8.7 g fat and 12.3 g CHO) and standard meal supplementation (SM: 1039 kJ energy, 9.9 g protein, 9.5 g fat, and 29.4 g CHO) consumed daily following a week of baseline measures. Eighteen participants finished both interventions and one only completed HP. TEI (mean ± SD) was not different between baseline (11148 ± 3347 kJ) and HP (10705 ± 3143 kJ) nor between baseline and SM (12381 ± 3877 kJ), however, TEI was greater with SM than HP (923 ± 4015 kJ p = .043). Protein intake (%TEI) was greater with HP (22.4 ±6.2%) than baseline (19.4 ± 5.4%; p = .008) but not SM (20.0 ± 5.0%). No differences in absolute daily protein intake were found. Absolute CHO intake was greater with SM than HP (52.0 ± 89.5 g, p = .006). No differences in fat intake were found. Body mass did not change between baseline (82.7 ± 11.2 kg) and either HP (83.1 ± 11.7 kg) or SM (82.9 ± 11.0 kg). Protein supplementation increases the relative proportion of protein in the diet, but doesn’t increase the absolute amount of total protein or energy consumed. Thus some compensation by a reduction in other foods occurs. This is in contrast to a mixed nutrient supplement, which does not alter the proportion of protein consumed but does increase TEI.
Alistair R. Mallard, Rebecca T. McLay-Cooke and Nancy J. Rehrer
Katya Vargas-Ortiz, Victoriano Perez-Vazquez, Francisco J. Diaz-Cisneros, Arturo Figueroa, Lizbeth M. Jiménez-Flores, Gustavo Rodriguez-DelaRosa and Maciste H. Macias
Sirtuin 3 enzyme (SIRT3) is involved in the regulation of mitochondrial energy homeostasis by activating Peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α). Murine models have shown that the protein SIRT3 was modified by exercise and diet, however, the effect of exercise without diet in humans has not been examined. Propose of this paper was to analyze the effect of aerobic training on SIRT3 and PGC-1α in skeletal muscle of overweight adolescents without change in caloric intake. Fourteen overweight or obese male adolescents (15.5 ± 0.8 years) trained 3 days-week/50 min x session, at 70-80% of maximal heart rate for 12 weeks. Anthropometrics and skeletal muscle biopsies from the vastus lateralis were taken before and after the exercise program to measure adiposity, SIRT3, and PGC-1α proteins. Peak aerobic capacity (VO2peak) was estimated before and after training. The participants did not change their eating habits during the intervention. SIRT3 (1.05 ± 0.11 vs. 1.25 ± 0.14 AU, p = .014) and PGC-1a (1.06 ± 0.15 Vs 1.39 ± 0.20 AU, p = .009) increased. Fat percentage and waist circumference decreased (p < .05). VO2peak increased after training (p < .001). There was a significant association between SIRT3 and PGC-1α after training program. These data suggest that aerobic training increased SIRT3 and PGC-1a expression levels in sedentary, overweight, or obese adolescents.
Melinda M. Manore, Janice Thompson and Marcy Russo
This study presents the diet and exercise strategies of a world-class bodybuilder during an 8-week precompetition period. Weighed food records were kept daily, and body fat, resting metabolic rate (RMR),
Luisa Aires, Pedro Silva, Gustavo Silva, Maria Paula Santos, José Carlos Ribeiro and Jorge Mota
The purpose of this study was to analyze the relation between body mass index (BMI), Cardiorespiratory Fitness (CRF), and levels of physical activity (PA) from sedentary to very vigorous intensities, measured by accelerometry, in students from a middle and high school.
This cross-sectional study included 111 children and adolescents, age 11 to 18 years. PA was assessed with an accelerometer for 7 consecutive days (1 minute epoch) using specific cut-points. PA components were derived using special written software (MAHUffe). CRF was assessed by maximal multistage 20m shuttle run. T-test was used to test differences between BMI groups, Pearson’s correlation, to analyze correlations between all variables and multinomial logistic regression, and to predict the value of BMI categories.
This paper provides evidence that BMI was inversely and significantly correlated with CRF. Only CRF was correlated with Vigorous and Very Vigorous PA levels and total amount of PA. Children with Overweight/Obesity were less likely to perform more laps than normal weight counterparts. The total amount or intensity level of PA did not show any influence on BMI level.
Low CRF is strongly associated with obesity, which highlights the importance of increasing CRF for a protective effect even in youth. No associations were found for PA and BMI.
Kayla W. Carrigan, Trent A. Petrie and Carlin M. Anderson
Female athletes have been identified as a subpopulation at heightened risk for disordered eating attitudes and behaviors, particularly due to weight pressures in their environment. Using a sample of 414 NCAA Division-I female collegiate athletes, we examined the relations of required team weigh-ins or self-weighing on disordered eating attitudes and behaviors. Through a series of multivariate analyses, we determined that team weighs were significantly unrelated to all outcome measures. Self-weighing, however, differentiated the athletes’ scores on internalization, body satisfaction, dietary restraint, negative affect, and bulimic symptomatology; athletes who self-weighed three or more times a week reported significantly higher levels of pathology across all measures. Mandatory team-conducted weigh-ins appear to not be a salient pressure for female gymnasts and swimmer/divers, although the frequency of their self-weighing may represent a level of self-monitoring that is associated with greater endorsement of disordered eating attitudes and behaviors.
Grant M. Tinsley and Brett S. Nickerson
When estimating body composition, a pervasive recommendation is to perform assessments after a period of rest and fasting. This recommendation seeks to minimize biological error induced by daily activities, such as food and fluid ingestion or exercise. Overnight fasts are implemented for a variety
Thiago Correa Porto Gonçalves, Atila Alexandre Trapé, Jhennyfer Aline Lima Rodrigues, Simone Sakagute Tavares and Carlos Roberto Bueno Junior
on body composition, BP, antioxidant capacity, oxidative stress, lipid profile, nitrite concentration, and aerobic capacity in 50- to 79-year-old women. Identification of the genetic characteristics and their influence in response to exercise training will enable selection of the training method that
Giovanna Ghiani, Sara Magnani, Azzurra Doneddu, Gianmarco Sainas, Virginia Pinna, Marco Caboi, Girolamo Palazzolo, Filippo Tocco and Antonio Crisafulli
physical examination did not discover any cardiovascular, respiratory, or metabolic disease. His BM (measured in kilograms) and height (measured in centimeters) were also assessed. Body composition was calculated with the skinfold thickness method (triceps, biceps, subscapular, and suprailiac skinfold
Darryn S. Willoughby, Kaitlan N. Beretich, Marcus Chen and LesLee K. Funderburk
category were not eligible to participate in the study. The participants had a venous blood sample obtained and then underwent assessment for body composition and upper body and lower body muscle strength. The study’s personnel then supervised and instructed each participant on how to properly perform all
Joyce E. Ballard, Lorraine S. Wallace, David B. Holiday, Cassandra Herron, Liberty L. Harrington, Karen C. Mobbs and Patricia Cussen
This study assessed differences in bone-mineral density (BMD) and lean and fat tissues between 5 age groups of White men age 65–93 years. Lean and fat tissues were measured with absorptiometry and anthropometry, and BMD, with dual-energy X-ray absorptiometry. Forearm, spinal, and femoral T scores were used to classify BMD as normal, osteopenic, or osteoporotic. A questionnaire evaluated previous physical activity, calcium intake, and bone fractures. Significantly lower values in body weight, lean tissue, and forearm BMD occurred in the older age groups. Significant, positive relationships were found between total lean tissue and radial, spinal, and hip BMDs. For the total group, osteopenic and osteoporotic T scores, respectively, were femoral neck 70.6% and 9.8%, radius 27.5% and 25.5%, and spine 25.5% and 7.8%. Differences in BMD values were found between levels of lifestyle factors (dietary calcium and history of previous fractures). In conclusion, elderly men should be encouraged to maintain adequate total lean tissue because of its association with BMD.