This study investigated social cognitive determinants of creatine supplementation among 171 male, undergraduate, recreational weight-lifters. Participants responded to a packet of questionnaires that assessed their history and rate of creatine use, self-efficacy for improving their workout performance with and without creatine, and expected outcomes of improved workout performance and creatine use, as well as several other demographic variables. Fifty percent of the sample reported past creatine use. The data was used to establish the internal consistency, test-retest reliability and predictive validity of factor-based scales for valued outcome expectancies and disincentives for creatine use scales. A social cognitive model was shown to predict past creatine use (R² = .372). The results lay the groundwork for further examination of the determinants of creatine supplementation and the use of other controversial and potentially harmful performance-enhancing dietary supplements. / Master of Science

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 63-65). Also available via the Internet.

The purpose of this study was to determine the effects of false positive and false negative feedback upon the self-efficacy and performance of high and low self-esteem experienced weight lifters. Among a group of volunteers, 65 experienced male weight lifters were classified as either high or low self-esteem following administration of the Global Self-Worth Scale (Neemann & Harter, 1986). Each was qualified by the ability to perform a one repetition-maximum (1RM) bench press between 200 to 350 lbs., which was tested through a series of trials. Self-efficacy estimates for the 1RM bench press were obtained throughout the experiment. Trial sessions were accompanied by manipulated feedback, providing the subjects with either actual, inflated, or deflated values of weights lifted. High and low self-esteem subjects performed tasks differently with respect to the type of feedback received. During the first manipulative treatments, high self-esteem subjects lifted greater weights after receiving false positive feedback and lesser weights after receiving false negative feedback. At all times, low self esteem subjects did not perform differently after the receipt of either false positive or false negative feedback. An analysis of the self-efficacy data demonstrated that predictions for 1RM bench press performances were not influenced by levels of self-esteem. However, both high and low self-esteem subjects predicted that they would lift greater or lesser weights following the administration of, false positive or false negative feedback, respectively, and both groups of subjects predicted there would be no weight differences following administration of actual feedback. Correlation analyses, conducted to determine relationships between self-efficacy and performance, indicated that during the first day of manipulative feedback treatment there was a positive relationship between self-efficacy and subsequent performance change. Previous performance change and subsequent self-efficacy change were correlated only for high self-esteem subjects during day 2 of the treatment. A regression analysis revealed that self-efficacy change was a better predictor of subsequent performance change than previous performance change. In conclusion, false positive feedback increased self-efficacy and performance of high self-esteem subjects. False negative feedback showed no significant change for either low or high self-esteem subjects. / Graduation date: 1993

Elastic bands are becoming more popular in strength and power training. Although increases in strength and power have been anecdotally reported with high loads of elastic resistance, there is no research on large band tensions and their effects on force and power variables. The purpose of this study was to quantify peak concentric force, peak concentric power and peak eccentric velocity produced by the subject when using differing levels of elastic resistance (0%, 20%, 50% and 75% of the total load being elastic resistance) in the bench press. Seven experienced male powerlifters and body builders participated in this study. Prior to subject testing all elastic bands were calibrated for force output throughout the bench press range of motion. Each subject performed a single repetition maximum press to determine the total correct testing load (85% of maximum press). The subjects then performed four presses with various elastic band resistances, each having the total equivalent weight of 85% of the subject’s maximal press weight at lockout. Dependent variables were peak concentric force, peak concentric power, and peak eccentric velocity as produced by the subject. A one-way ANOVA was used to determine the differences among the four levels of elastic resistance (ER) used in the study (α = 0.05). Compared to the baseline condition (2123.6 ± 499.9N), significantly lower average peak concentric force was observed with ER of 75% (1451.2 ± 151.0N, 31.9% decrease) (p = .010) and with an ER of 50% (1781.1 ± 174.3N, 16.4% decrease) (p = .052). When compared with baseline peak concentric power (702.6 ± 274.6W), higher peak power was observed in all band trials: 20% (895.2 ± 187.7W, 27.4% increase), 50% (972.5 ± 189.8W, 38.4% increase) and 75% (979.6 ± 171.0W, 39.4% increase) (p = .009; p = .007; p = .033, respectively). There was no significant difference in peak concentric power in any ER trials. No significant differences (p = .080) were seen in peak eccentric velocity. Therefore ER loads of 20, 50 and 75% provide greater stimuli for producing peak concentric power than no ER, with only a 20% load of ER maintaining the same peak concentric force production as baseline. ER loads of 50 and 75% may not be as effective a stimuli as free weights when the training objective is to increase force production. / School of Physical Education, Sport, and Exercise Science

Thesis (M.S.)-- Springfield College, 2006. / Bibliography: leaves 127-140.

Equivocal results for imagery as a beneficial adjunct to performance may be due to diverse methodologies as well as a lack of clarity about the relationship between imagery ability and imagery perspective. This study used a randomized group design with repeated measures to evaluate the effect of imagery content and perspective on strength. Subjects were 44 women, ages 19 to 34, classified as beginning weight lifters. All were pre-tested on imagery ability and knee joint strength. Subjects were randomly assigned to one of three training conditions: (1) an internal imagery perspective; (2) an external imagery perspective, and (3) no imagery training. Training was conducted twice per week for eight weeks. Subjects were also asked to work out a third time. The dependent measure to assess strength at the beginning, middle, and end of the eight-weeks was the Cybex II dynamometer. The dependent measure to assess imagery vividness was the Betts questionnaire Upon Mental Imagery. Imagery perspective was measured by the Imagination Exercise. Results of a two-way analysis of variance with repeated measures using Cybex II found significant strength differences for: (1) all groups and (2) the internal imagery group. A significant linear trend was also found between groups. Additionally, a two-way analysis of variance with repeated measures, using imagery ratings found significant improvement in kinesthetic vividness for all groups. This investigation is the first experimental study using beginning athletes to demonstrate significant performance effects using mental training above and beyond significant effects due to physical training. / Master of Science

The purpose of this study was to examine the effects of a hypocaloric liquid diet, with varied protein/carbohydrate ratios, on two groups of male weightlifters. A maintenance diet was consumed by all subjects for one week prior to the experimental phase, and all subjects participated in a resistance weight training program. The experimental groups consumed either a moderate protein/high carbohydrate diet (MP/HC) with 0.8 g/kg body wt/d protein or high protein/moderate carbohydrate diet (HP /MC) with 1.6 g/kg body wt/d protein diet for the experimental week. Twenty-four hour urine samples were collected daily and two exercising sweat samples were taken for each subject. Fecal nitrogen losses were estimated and added to urine and sweat values for daily nitrogen excretion. There was a significant difference in nitrogen balance between the groups over time. Nitrogen balance was positive for the HP/MC group (4.13 g/d) and negative for the MP/HC group ( -3.19 g/d) . The results of this study suggest the possibility that weightlifters consuming a hypocaloric diet should consume more than the US RDA for protein to maximize retention of body protein. / M.S.

This study describes bone mineral index (g/cm²) of the distal and mid forearm, spine and hip in gymnasts/weight trainers, and runners with varying menstrual status. 12 eumenorrheic gymnasts/weight trainers (EGW), 11 eumenorrheic runners (ERU), 8 oligomenorrheic gymnasts/weight trainers (OGW), 3 oligomenorrheic runners (ORU) 4 amenorrheic runners (ARU) and a eumenorrheic control group (EC) of 18 subjects were examined. Bone mineral index (BMI) was measured using single and dual photon absorptiometry. EGW had greater BMI than ARU and EC (spine, hip and distal and mid forearm) and ERU (femur and distal forearm). The ARU were not significantly lower in BMI than the ERU. The ARU were only significantly lower in BMI than the EC at the distal forearm. OGW were not significantly greater in BMI than ORU. The OGW had greater BMI than the ARU (spine, femur and distal forearm), ERU and EC (femur and distal forearm). These results show higher BMI in gymnasts/weight trainers, independent of menstrual status, than in runners and controls.

Manufacturers of amino acid supplements claim that they can act as natural stercoids. Eighteen experienced male weight lifters were studied to test this hypothesis for the amino acid arginine. / Master of Science

Twelve male weight lifters were used to study the effect of oral arginine consumption on growth hormone (hGH) , arginine (Arg), and somatomedin (IGF-1) concentrations. Subjects were randomly assigned to treatment or placebo groups. Following a week of controlled exercise and diet, fasted subjects took either an acute dose of arginine hydrochloride or casein (placebo), at 0.1 g/kg BW. Blood samples were drawn every 15 min, for 90 min after ingestion. All samples were analyzed for hGH and Arg, and IGF-1 was measured in the baseline sample. Subjects then underwent 10 days of caloric restriction, consuming a liquid diet of 22 kcal/kg BW/d. Subjects took either arginine or casein supplements in two doses of 0.1 g/kg BW twice daily, for a total dose of 0.2 g/kg BW/d. The weight lifting protocol remained unchanged. On day 17, subjects were again tested for the acute response to a single dose of 0.1 g/kg BW supplement (arginine or placebo) over 90 min. Blood was collected and analyzed as before. No change in hGH and Arg occurred 90 min after consumption of the arginine supplement, regardless of dietary condition. However, arginine supplementation caused overall higher hGH and Arg levels (2.64 ng/ml and 0.87 mmol/l) compared to placebo (1.36 ng/ml and 0.71 mmol/l) during caloric restriction. IGF-1 did not change in either group under either diet. Thus, oral arginine supplementation at 0.1 g/kg BW did not produce a rise in hGH or Arg after 90 min, and did not affect overall hGH status, as measured by IGF-1, during energy restriction and supplementation. / Master of Science