Search

The article presents a study which aims to determine the relative contributions of isokinetic forearm flexion (FLX) and extension (EXT) peak torque (PT), and fat-free mass (FFM) to the prediction of estimated propulsive force (EPF) in young male swimmers. These swimmers were measured for FLX and EXT PT. The results suggest that age-related increases in HT and FFM as well as training for increases in FLX and EXT strength may improve propulsive force and swimming performance.

The article discusses research which was conducted to investigate the age related patterns of differences in height, body mass, per cent body fat, body mass index and skin folds in 11 to 18 year old wrestlers. Researchers evaluated 130 wrestlers. They found that most wrestlers were similar in height but had smaller upper body skin folds when compared to National Health and Nutrition Examination Survey (NHANES) samples and that wrestling had favorable effects on measures of adiposity.

The article discusses a randomized, double-blinded, placebo-controlled, crossover study investigating acute metabolic, cardiovascular, and perceptual responses to a thermogenic nutritional supplement at rest, during exercise, and recovery in men approximately 23.5 years old. Topics include caffeine in thermogenic nutritional supplements, the effect of caffeine on energy expenditure (EE), and statistics on heart rate (HR), respiratory exchange rate (RER), and perceived exertion (RPE).

The article discusses research which was conducted to investigate the effects of 28 days of polyethylene glycosylated creatine (PEG-creatine) supplementation (1.25 and 2.50 grams daily) on anaerobic performance measures and body composition. Researchers evaluated the supplementation with 77 adult men. They found that the supplementation at 1.25 or 2.50 grams per day had an ergogenic effect on lower-body vertical power, agility, change-of-direction ability, upper-body muscular endurance and body mass.

The article presents the results of a study which investigated the age-related changes in the anthropometric measurements of female high school gymnasts. An overview of related previous research is provided, along with details of the experimental protocol, which involved body mass index ratings and skinfold measurements of body fat.

The article presents the results of a study which compared young male and female sprint swimmers in terms of anthropometric sex differences. An overview of related previous research is provided, along with details of the experimental protocol, which involved measurements of body composition and anthropometric variables.

The article presents the results of a study which investigated the impact of creatine supplements on muscle strength in men. An overview of related previous research is provided, along with details of the experimental protocol, which was double-blind, randomized, and placebo-controlled. It was found that polyethylene glycosylated creatine supplements increased bench pressing performance.

The article presents the results of a study which investigated the relationship between anthropomorphic variables and torque force generation in young male wrestlers. An overview of related previous research is provided, along with details of the experimental protocol. It was found that age-related changes had a more significant effect on torque generation than body-size variables.

The article reports on research conducted to examine the effects a caffeine-containing supplement (SUPP) had on one repetition maximum (1 RM) bench press and leg extension strength, and time to exhaustion (TTE), during cycle ergometry. Researchers evaluated 21 subjects. They found that the supplement had no effect on 1RM bench press strength, one repetition maximum leg extension strength, or TTE.

The article presents a study which compared the patterns of responses for plasma ammonia concentration during heavy- and moderate-intensity cycle ergometry. The study also looked at the relationship between plasma and oxygen update. Results indicate a possible relationship between exercise-induced hyperammonemia and oxygen uptake.

This investigation examined the effects of a protease supplement on selected markers of muscle damage and delayed-onset muscle soreness (DOMS). The study used a double-blinded, placebo-controlled, crossover design. Twenty men (mean ± SD age = 21.0 ± 3.1 years) were randomly assigned to either a supplement group (SUPP) or a placebo group (PLAC). All subjects were tested for unilateral isometric forearm flexion strength, hanging joint angle, relaxed arm circumference, subjective pain rating, and plasma creatine kinase activity and myoglobin concentration. The testing occurred before (TIME1), immediately after (TIME2), and 24 (TIME3), 48 (TIME4), and 72 (TIME5) hours after a bout of eccentric exercise. During these tests, the subjects in the SUPP group ingested a protease supplement. The subjects in the PLAC group took microcrystalline cellulose. After testing at TIME5 and 2 weeks of rest, the subjects were crossed over into the opposite group and performed the same tests as during visits 1-5, but with the opposite limb. Overall, isometric forearm flexion strength was greater (7.6%) for the SUPP group than for the PLAC group, despite nearly identical (difference = 0.14 N·m, p = 0.940) mean strength values before (TIME1) the eccentric exercise protocol. There were no between-group differences for hanging joint angle, relaxed arm circumference, subjective pain ratings, and plasma creatine kinase activity and myoglobin concentration from TIME1 to TIME5. These findings provided initial evidence that the protease supplement may be useful for reducing strength loss immediately after eccentric exercise and for aiding in short-term strength recovery. The protease supplement had no effect, however, on the perception of pain associated with DOMS or the blood markers of muscle damage. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the effects of daily administration of a supplement that contained caffeine in conjunction with 8 weeks of aerobic training on O2peak, time to running exhaustion at 90% O2peak, body weight, and body composition. Thirty-six college students (14 men and 22 women; mean ± SD, age 22.4 ± 2.9 years) volunteered for this investigation and were randomized into either a placebo (n = 18) or supplement group (n = 18). The subjects ingested 1 dose (3 pills = 201 mg of caffeine) of the placebo or supplement per day during the study period. In addition, the subjects performed treadmill running for 45 minutes at 75% of the heart rate at O2peak, three times per week for 8 weeks. All subjects were tested pretraining and posttraining for O2peak, time to running exhaustion (TRE) at 90% O2peak, body weight (BW), percentage body fat (%FAT), fat weight (FW), and fat-free weight (FFW). The results indicated that there were equivalent training-induced increases (p < 0.05) in O2 peak and TRE for the supplement and placebo groups, but no changes (p > 0.05) in BW, %FAT, FW, or FFW for either group. These findings indicated that chronic use of the caffeine-containing supplement in the present study, in conjunction with aerobic training, provided no ergogenic effects as measured by O2peak and TRE, and the supplement was of no benefit for altering body weight or body composition. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the acute effects of a caffeine-containing supplement on upper-and lower-body strength and muscular endurance as well as anaerobic capabilities. Thirty-seven resistance-trained men (mean ± SD, age: 21 ± 2 years) volunteered to participate in this study. On the first laboratory visit, the subjects performed 2 Wingate Anaerobic Tests (WAnTs) to determine peak power (PP) and mean power (MP), as well as tests for 1 repetition maximum (1RM), dynamic constant external resistance strength, and muscular endurance (TOTV; total volume of weight lifted during an endurance test with 80% of the 1RM) on the bilateral leg extension (LE) and free-weight bench press (BP) exercises. Following a minimum of 48 hours of rest, the subjects returned to the laboratory for the second testing session and were randomly assigned to 1 of 2 groups: a supplement group (SUPP; n = 17), which ingested a caffeine-containing supplement, or a placebo group (PLAC; n = 20), which ingested a cellulose placebo. One hour after ingesting either the caffeine-containing supplement or the placebo, the subjects performed 2 WAnTs and were tested for 1RM strength and muscular endurance on the LE and BP exercises. The results indicated that there was a significant (p < 0.05) increase in BP 1RM for the SUPP group, but not for the PLAC group. The caffeine-containing supplement had no effect, however, on LE 1RM, LE TOTV, BP TOTV, PP, and MP. Thus, the caffeine-containing supplement may be an effective supplement for increasing upper-body strength and, therefore, could be useful for competitive and recreational athletes who perform resistance training. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effects of resistance training in combination with a leucine and whey protein supplement or a carbohydrate placebo on strength and muscle cross-sectional area (CSA). Thirty-three men (mean age ± SD = 22.4 ± 2.4 years) were assigned to 1 of 3 groups: (1) supplementation group (SUPP), (2) placebo group (PL), or (3) control group (CON). The SUPP and PL performed unilateral training of the leg extensor muscles with the nondominant limb for 8 weeks. The strength of each limb, muscle CSA of the quadriceps femoris (QF), and body composition were assessed pretraining and posttraining. The results indicated significant increases in strength for both limbs in the SUPP but only the trained limb in the PL. The increase in strength for the trained limb of the SUPP was greater than that for the trained limb of the PL. There was no significant increase in strength for either limb in the CON. There were significant increases in the CSA of all muscles of the QF of the trained limb for the SUPP and PL, and of the vastus lateralis of the untrained limb for the SUPP. The increases in QF CSA did not differ between the SUPP and PL. No significant CSA changes were found for either limb in the CON. There were no significant changes in body composition for the SUPP, PL, or CON. The current findings suggest that leucine and whey protein supplementation may provide an ergogenic effect which enhances the acquisition of strength beyond that achieved with resistance training and a carbohydrate placebo. [ABSTRACT FROM AUTHOR]

The purpose of this investigation was to determine the accuracy of near-infrared interactance (NIR) instruments and population-specific NIR equations for estimating percent body fat (% fat) in young wrestlers. Forty-four white male youth wrestlers (mean age 6SD = 11.0 ± 2.1 years) volunteered for this study. Thirteen NIR % fat estimates were cross-validated against the criterion % fat from underwater weighing. The results of this study indicated that the total error (TE) values associated with the NIR instrument generated % fat estimates as well as % fat estimates from population-specific NIR equations developed for high school wrestlers or adult men were too large (TE = 5.7-27.3% fat) to be used with young wrestlers. Based on the present findings, it is recommended that new NIR equations be developed and validated specifically for use in young male athletes. [ABSTRACT FROM AUTHOR]

Physical and anthropometric characteristics have been associated with differences between levels of swimming performance, swimming events, training status, gender, and age. It has been suggested that the greater body fatness observed in girl swimmers than boy swimmers could explain the gender differences in performance. Few studies, however, have examined gender differences in the physical and anthropometric characteristics of young swimmers. The purpose of this study was to compare the body composition, body build, and anthropometric characteristics of boy and girl sprint swimmers. Two groups (boys, n = 38 and girls, n = 31) of sprint swimmers (mean age ± SD = 11.03 ± 2.29 and 10.45 ± 2.29, years, respectively) volunteered for this study. The subjects were members of local swimming clubs who competed in sprint swimming events (≤ 200 m). Gender comparisons were made for age, body weight (BW), height (HT), fat-free weight (FFW), percent body fat (%fat), endomorphic rating, mesomorphic rating, ectomorphic rating, sum of 12 diameters, sum of 11circumferences, biacromial diameter/biiliac diameter, and FFW/HT. The results of the independent t-tests indicated that the only mean differences between the boy and girl sprint swimmers were for % fat (boys = 9.40 ± 5.35 % fat; girls = 12.73 ± 6.19 % fat) and endomorphic rating (boys = 2.87 ± 0.96; girls = 4.29 ± 1.22). For the current age group of sprint swimmers, the only gender differences were for measures associated with body fatness and there were no differences for body build measures associated with musculoskeletal size, muscularity, skeletal size, total body mass, or body breadth dimensions. Further studies are needed to examine gender differences in the body composition and body build of distance swimmers, older sprint and distance swimmers, and athletes in sports other than swimming. These findings suggest that gender differences in sprint swimming performance may be reduced through training programs for girls designed to reduce body fatness. [ABSTRACT FROM AUTHOR]