Prevalence of Disordered Eating and Pathogenic Weight Control Behaviors Among NCAA Division I Female Collegiate Gymnasts and Swimmers

Abstract

Nine trained trackmen were divided into experimental (nonmilk) and control (milk) groups. Both groups participated in eight weeks of training. The experimental group was not permitted any milk, cheese, or ice cream except in those dishes in which milk was used in cooking. The controls consumed a minimum of three pints of milk daily and about two pints of ice cream each week. Steady state and all-out treadmill measures were obtained as well as diet recall records. During the period of this investigation no significant effects which might be attributed to milk were observed on performance. With exclusion of milk from the diet the intake of calcium, vitamin A, and riboflavin dropped significantly and below the recommended minimum allowances.     

Exercise training and antioxidant supplementation independently improve cognitive function in adult male and female GFAP-APOE mice

PurposeThe purpose of this study was to determine if antioxidant supplementation, moderate exercise, and the combination of both treatments could ameliorate cognitive performance in adult mice and whether the apolipoprotein E (APOE) genotype as well as sex could influence the functional outcomes of the treatments.MethodsFor a period of 16 weeks, separate groups of male and female mice expressing either the human APOE3 or APOE4 isoforms were fed either a control diet (NIH-31) or the control diet supplemented with vitamins E and C (1.12 IU/g diet α-tocopheryl acetate and 1.65 mg/g ascorbic acid). The mice were further separated into a sedentary group or a group that followed a daily exercise regimen. After 8 weeks on the treatments, the mice were administered a battery of functional tests including tests to measure cognitive and affective function.ResultsThere was no effect of genotype or treatment on the learning performance in the Morris water maze. In the discriminated avoidance task, APOE4 mice performed better in learning the discrimination component of the task. Overall, exercise improved performance of APOE4 and APOE3 mice on various aspects of the active avoidance task. Antioxidant supplementation improved performance only in the APOE4 mice. On the test for anxiety, APOE4 mice spent more time in the open arms and supplementation with antioxidant reversed that effect.ConclusionExercise was the most effective treatment at improving cognitive function in both genotypes and sex, while antioxidants seemed to be effective only in the APOE4. In young adult mice only non-spatial learning and memory were improved. The combination of the two treatments did not yield further improvement in cognition, and there was no antagonistic action of the antioxidant supplementation on the beneficial effects of exercise.     

Effect of a Single Day's Swimming on Selected Components of Athletic Performance

Abstract

The purpose of this investigation was to study the effect of swimming on selected components of athletic performance as measured by the following tests: back strength, leg strength, bicycle ergometer (combination of strength and endurance, but predominantly endurance), and vertical jump (explosive power). Subjects were pretested for three days on each test, after which they participated in 45 minutes of swimming, and performance was tested oh one test one hour after the swim on any given day. A single day's swimming was found to significantly affect the vertical jump, but other performance tests were not affected.     

Post-exercise ingestion of different amounts of protein affects plasma insulin concentration in humans

Abstract

The synergistic stimulating effect of combined intake of carbohydrate and protein on plasma insulin concentration has been reported previously. However, it remains unclear whether the amount of protein ingested after exercise affects the concentrations of plasma insulin and amino acids. This study of trained men compared the effects of post-exercise co-ingestion of carbohydrate plus different amounts of whey protein hydrolysates (WPHs) with carbohydrate alone on (1) blood biochemical parameters of carbohydrate metabolism during the post-exercise phase, and (2) endurance performance. Eight trained men exercised continuously for 70 min. Immediately after exercise and 30, 60, 90, and 120 min later, the participants received supplements containing: (1) 17.5 g carbohydrate, (2) 3.0 g WPHs and 17.5 g carbohydrate (L-WPH), or (3) 8.0 g WPHs and 17.5 g carbohydrate (H-WPH). After a 2-h recovery period, the participants performed an endurance performance test. The concentrations of blood glucose were lower and plasma insulin significantly higher in the H-WPH trial compared with the carbohydrate trial. The concentrations of plasma amino acids were increased in a dose-dependent manner following ingestion of different amounts of WPHs with carbohydrate. Endurance performance was not significantly different between the three trials. Co-ingestion of carbohydrate and H-WPH was more effective than ingestion of carbohydrate alone for stimulating insulin secretion and increasing the availability of plasma amino acids. These results suggest that plasma concentrations of amino acids during the recovery period are determined by the amount of dietary protein ingested, and that it is necessary to increase the concentration of plasma amino acids above a certain level to stimulate insulin secretion.     

Comparison of Indirect Calorimetry- and Accelerometry-Based Energy Expenditure During Children‘s Discrete Skill Performance

ABSTRACT

Purpose: To compare children’s energy expenditure (EE) levels during object projection skill performance (OPSP; e.g., kicking, throwing, striking) as assessed by hip- and wrist-worn accelerometers. Method: Forty-two children (female n = 20, Mage = 8.1 ± 0.8 years) performed three, nine-minute sessions of kicking, over-arm throwing, and striking at performance intervals of 6, 12, and 30 seconds. EE was estimated using indirect calorimetry (COSMED k4b2) and accelerometers (ActiGraph GT3X+) worn on three different locations (hip, dominant-wrist, and non-dominant-wrist) using four commonly used cut-points. Bland-Altman plots were used to analyze the agreement in EE estimations between accelerometry and indirect calorimetry (METS). Chi-square goodness of fit tests were used to examine the agreement between accelerometry and indirect calorimetry. Results: Hip- and wrist-worn accelerometers underestimated EE, compared to indirect calorimetry, during all performance conditions. Skill practice at a rate of two trials per minute resulted in the equivalent of moderate PA and five trials per minute resulted in vigorous PA (as measured by indirect calorimetry), yet was only categorized as light and/or moderate activity by all measured forms of accelerometry. Conclusion: This is one of the first studies to evaluate the ability of hip- and wrist-worn accelerometers to predict PA intensity levels during OPSP in children. These data may significantly impact PA intervention measurement strategies by revealing the lack of validity in accelerometers to accurately predict PA levels during OPSP in children.     

Relationship of Ankle Strength and Test Order to Static Balance Performance

Abstract

The relationship of dorsi and plantar flexion strength to static balance performance was determined. In addition, the effect that the order of balance test administration had upon balance performance was established. Fifty-six college females completed tests of plantar and dorsi flexion strength, the Bass Stick Test, the Bass Stick Test without visual cues, and the Bass Stick Test raised to a height of 4 feet above the floor. Subjects were randomly assigned to one of six different test order groups. Strength of the dorsi and plantar flexors of the foot was not related to any of the three balance tests. The Bass Stick Test was performed significantly better by the two groups which took this test as the last of the three, regardless of sequence. The group experiencing the blindfolded test first produced balance performances that were inferior to those of the other groups. In general, the practice effect resultant from taking a balance test last in order facilitated performance more than fatigue inhibited it.     

Effects of Exercise and Milk Consumption on Blood Serum Cholesterol in Rats

Abstract

This study investigated the effects of exercise on blood cholesterol and correlated those effects with estimates of body fat through experiments with 45 albino weanling rats (15 litter mate trios). The rats were confined to individual cages in a temperature-controlled room and fed a stock diet until they were 11 weeks old. At this time the trios were divided. Group A was continued on a stock diet and exercised for an hour in the morning and an hour in the afternoon by forced swimming. Group B was subjected to the same exercise but a portion of the stock diet was replaced with powdered whole milk, so that 30 percent of the caloric intake was derived from the whole milk supplement. Group C was fed the stock diet but activity was restricted. After 15 weeks blood samples were taken, the animals sacrificed, and the heart and adrenals weighed. The specific gravity of the carcass was also determined. Exercise resulted in a statistically significant decrease in total and free blood serum cholesterol concentration. These animals were also leaner and had larger hearts and adrenal glands. Serum cholesterol was negatively related to carcass specific gravity. The milk supplement had no significant effect on any of these measures. Several possible explanations for the effects of exercise on blood cholesterol are discussed.     

Impact of a Simulated Stress Training Program on the Tactical Shooting Performance of SWAT Trainees

ABSTRACT

Purpose: To create a high-stress shooting among the crowd (SAC) program and to examine its effectiveness in reducing SWAT trainees’ stress level and their shooting performance in a simulated hostage-rescue situation. Method: After the SAC program was created, it was evaluated using a pretest and posttest experimental design: 98 young male SWAT trainees were randomly divided into experiment and control groups, with the former group trained in hostage rescue, shooting with real persons (high stress), and the latter group trained with “dummy” men (low stress); training for both lasted three days. Their shooting performance was assessed by a tactical shooting test in both high- and low-stress tests in a counterbalanced order, before and after the training, and monitored during the training, as were their stress levels by a set of physical (heart rate [HR] and heart rate recovery time [HRRt]), psychological (salivary cortisol and α-amylase), and self-reported anxiety measures. Results: The SAC program created needed high-stress for hostage rescue situations as reflected in increased physical, psychological, and anxiety scores and reduced shooting performance. Even with short SAC training, SWAT trainees’ capacity in handling high stress and tactical shooting performance were significantly improved. HR, HRRt, and anxiety tests have been found to be effective in monitoring stress and should be a part of future SWAT training. Conclusion: A SAC program involving real people was created, and its effectiveness was confirmed using a pretest and posttest experimental design.     

Effect of citrulline on post-exercise rating of perceived exertion,muscle soreness,and blood lactate levels: A systematic review and meta-analysis

BackgroundCitrulline is one of the non-essential amino acids that is thought to improve exercise performance and reduce post-exercise muscle soreness. We conducted a systematic review and meta-analysis to determine the effect of citrulline supplements on the post-exercise rating of perceived exertion (RPE), muscle soreness, and blood lactate levels.MethodsA random effects model was used to calculate the effect sizes due to the high variability in the study design and study populations of the articles included. A systematic search of PubMed, Web of Science, and ClinicalTrials.gov was performed. Eligibility for study inclusion was limited to studies that were randomized controlled trials involving healthy individuals and that investigated the acute effect of citrulline supplements on RPE, muscle soreness, and blood lactate levels. The supplementation time frame was limited to 2 h before exercise. The types and number of participants, types of exercise tests performed, supplementation protocols for L-citrulline or citrulline malate, and primary (RPE and muscle soreness) and secondary (blood lactate level) study outcomes were extracted from the identified studies.ResultsThe analysis included 13 eligible articles including a total of 206 participants. The most frequent dosage used in the studies was 8 g of citrulline malate. Citrulline supplementation significantly reduced RPE (n = 7, p = 0.03) and muscle soreness 24-h and 48-h after post-exercise (n = 7, p = 0.04; n = 6, p = 0.25, respectively). However, citrulline supplementation did not significantly reduce muscle soreness 72-h post-exercise (n = 4, p = 0.62) or lower blood lactate levels (n = 8, p = 0.17).ConclusionCitrulline supplements significantly reduced post-exercise RPE and muscle soreness without affecting blood lactate levels.     

Age and Sex Differences in Motor Performance of 3 through 6 Year Old Children

Abstract

This study examined the relationship of age and sex to the performance of 3, 4, 5, and 6 year olds on seven motor performance test items. Although significant age and sex differences were found on most of the motor tests, it appears that age generally was related more to performance than was gender. Overall, change with age was fairly linear except perhaps for balancing and a general tapering in improvement in the 5 to 6 year old category. On the tests of throwing and balancing, gender was as important as age, or more so, in its relationship to performance. Boys were superior to girls at all ages on the throwing tests; girls were superior to boys at age 6 on the Balance test. Gender differences of a lesser magnitude were found on the Speed Run and Standing Long Jump tests with the performance of boys generally being superior to the performance of girls. Thus, it appears that gender differences in motor performance occur as early as the preschool years. Interestingly, except for the Balance test, on all the tests the 3 and 4 year old boys performed similarly and the 5 and 6 year old boys performed similarly. For the girls there were more significant differences from year to year in performance, with the data generally indicating at least three distinct skill groups for girls from age 3 to 6.     

Effects of Food Supplement on the Performance of Selected Gross Motor Tests

Abstract

The purpose of this investigation was to study the effect of a well-advertised vitamin-mineral supplement on three selected gross motor tests. Experimental and control groups were formed in two groups, football players and physical education majors. Measurements were taken at five different time periods covering a period of 12 weeks. No statistically significant differences in motor performance were found between those subjects taking the supplement and those taking the placebo.     

There Is an “I” in TEAM

Abstract

We investigated narcissism as a moderator of social loafing on a physical performance task. High and low narcissistic individuals twice performed a cycling task in same-sex teams of three: once when identifiability was low; and once when identifiability was high. A significant interaction between narcissism and identifiability was revealed, F(1, 40) = 4.09, p < .05, η² = .09 for performance. Follow-up tests indicated that high narcissists' performance significantly increased with greater identifiability, whereas low narcissists displayed no such performance differences. Results suggested that this effect was due to an increase in narcissists' on-task effort (ratings of perceived exertion and heart rate) when they knew that their performance was to be identified.     

Regular moderate aerobic exercise improves high-fat diet-induced nonalcoholic fatty liver disease via monoacylglycerol O-acyltransferase 1 pathway suppression

PurposeMonoacylglycerol O-acyltransferase 1 (MGAT1) is reported to play a key role in the development of diet-induced nonalcoholic fatty liver disease (NAFLD). Thus, this study investigated the effect of exercise on suppression of the MGAT1 pathway in NAFLD tissue of high-fat diet (HFD)-induced obese rats.MethodsMale Sprague-Dawley rats were fed an HFD containing 45% fat for 6 weeks. Upon confirmation that NAFLD had been induced in the obese animals, they were divided into HFD-fed groups provided with exercise (HFD + EXE) or without exercise (HFD) and a group given dietary adjustment (DA) only, for a further 6 weeks of intervention treatment. The 6-week regular moderate aerobic exercise consisted of an accommodation phase with increasing exercise. Lipid accumulation in the liver tissue was determined by Oil Red O staining. The MGAT1 and liver lipogenic gene mRNA levels were measured by qPCR, and their protein levels by western blot assay.ResultsOil Red O staining showed that NAFLD was successfully induced by HFD-fed. The gene expression of MGAT1 was significantly lower in HFD + EXE than HFD. However, there was no significant difference between HFD + EXE and DA. The protein expression of MGAT1 was significantly lower in HFD + EXE than both HFD and DA. Messenger RNA and protein expression of other lipogenic genes were not different among groups. These data indicate that exercise suppresses MGAT1 pathway regardless of HFD feeding; in part, this effect could be greater than DA.ConclusionOur data suggest that exercise can improve NAFLD, which is probably due to suppression of MGAT1 pathway.     

Relative Isometric Endurance and Different Levels of Athletic Achievement

Abstract

Relative isometric endurance tests of 50, 60, 70, and 80 percent weight loads were used to evaluate the muscular endurance of three groups of male college students. The 47 students were grouped according to level of athletic achievement. Analysis of variance models failed to detect any differences between the endurance of the three groups. Consideration was given to the use of relative endurance tests for evaluating levels of motivation.     

Response of brain-derived neurotrophic factor to combining cognitive and physical exercise

Purpose: Brain-derived neurotrophic factor (BDNF) is well known for its potential to promote brain plasticity. It has been proposed that combining cognitive and physical exercise (CCPE) may have the potential to generate more synergistic benefits in cognitive function than either cognitive exercise (CE) or physical exercise (PE) alone. The purpose of this study was to examine acute responses of peripheral BDNF levels and cognitive performance to CE, PE, and CCPE.

Methods: Thirteen healthy adult men participated in four experimental sessions; a 30-min CE, a 30-min cycling PE at an intensity of 60% peak oxygen uptake, a 30-min CCPE at the same intensity as PE, and a 30-min session of complete rest. Plasma BDNF levels and cognitive performance were measured before and after each session.

Results: Both PE and CCPE significantly increased plasma BDNF levels (p?p?≥?.05), and there was no significant difference in peripheral BDNF levels between PE and CCPE (p?≥?.05). No session induced a significant change in cognitive performance (p?≥?.05).

Conclusions: Our study suggests that CE and PE have different responses of peripheral BDNF levels and that CCPE had no additional or synergistic effect on peripheral BDNF levels compared with PE alone. This study offers further insights into the potential mechanisms underlying the respective roles of CE, PE, and CCPE for peripheral BDNF levels and cognitive performance.     

Effects of the Instructional Set in the Bandwidth Feedback Paradigm on Motor Skill Acquisition

ABSTRACT

Purpose: This study examined the relationships between the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1) and resting heart rate variability (HRV) and submaximal 5?-5? test derived measures in novice male soccer players. Methods: Forty players (11.54 ± 0.58 years) from a soccer academy participated in this study, performing physical tests on two different days, separated by 48 h, as follows: (day 1) resting HRV and Yo-Yo IR1 test, and (day 2) anthropometric assessments (for peak height velocity assessment [PHV]) and the 5?-5? test. The Pearson product-moment correlation coefficient was used to determine the correlations between Yo-Yo IR1 performance and the remaining variables. A partial correlation analysis was further performed using age, stature, body mass, distance to PHV, and age at PHV as “confounders.” Results: The highest correlation score was observed between Yo-Yo IR1 performance and resting HRV, when the absolute age was used as confounder (r = 0.72; p < .05). Conclusions: We observed that a practical measure of parasympathetic activity at rest is largely associated with performance obtained during a traditional intermittent endurance performance test.     

Movement Education: Its Effect on Motor Skill Performance

Abstract

The purposes of the present study were to evaluate transfer of movement education training to new skill performance and to evaluate skill improvement as a result of movement education and traditional training. The subjects were 47 first grade students who were in one of two classes. Each physical education class received one 30-minute class and one 20-minute class per week for 20 weeks. Subjects were taught movement principles either by a movement education approach or by a traditional approach. Johnson's Throw and Catch Test (1962) and a batting test for distance were used as pretests. These same tests were repeated as post tests in addition to two other tests which measured performance on striking and kicking distance and accuracy. Teaching approach groups were not significantly different on the latter two tests which measured the transfer of training effect. Traditional learning was better than movement education in developing throwing, catching, and batting performance. These results suggest that when one's objective is to teach a specific skill within a relatively short time period, a command style with demonstration is better than movement education.     

Physical activity levels,game performance and friendship goals using two different pedagogical models: Sport Education and Direct Instruction

Background: Advances in technology have changed children’s lifestyle so much that the majority of them do not meet the recommended 60 min of moderate to vigorous physical activity every day. Compulsory Physical Education has been highlighted as an ideal context to achieve the suggested physical activity (PA) goals, since it could be the only place where some students become truly physically active. In those classes, the teacher selects a pedagogical approach and this selection could be vital to meet the advised PA levels.

Purpose: The goal was to assess the effects of two instructional approaches, Sport Education Model (SEM) and Direct Instruction (DI) in Primary Education students’ physical activity intensity levels, game performance, and friendship goals.

Method: A total of 88 students with an average age of 11.16?±?0.63 years, enrolled in two year-5 (from 10 to11 years) and two year-6 (from 11 to 12 years) Physical Education classes of the same school agreed to participate. The number of participants in the SEM was 47 and in DI was 41. The schools’ administration distributed one class of each grade to the experimental group, which experienced SEM, and to the non-equivalent group, which experienced DI. The content selected for both study groups was the same: Handball. Both study groups experienced a 15-session learning unit (45 min per class, three sessions per week). The goal was to conduct the experiment in a non-manipulated (intact) educational context. It followed a pre-test, post-test, experimental, non-equivalent group design. Participants wore Actigraph GT3X accelerometers in order to monitor physical activity levels, answered questionnaires to assess friendship goals, and their game performance was assessed using the Game Performance Assessment instrument (GPAI).

Results: Results showed that students who experienced the SEM had significantly higher light and moderate physical activity levels, friendship-approach and friendship-avoidance goals, while the ones who experienced DI had significantly higher sedentary physical activity levels. The GPAI scores showed significant gains in students’ game performance in both study groups, but these were larger in the SEM one.

Conclusions: The SEM could be considered more effective than DI to improve Primary Education students’ PA levels, game performance and friendship goals.     

The Effect of Preliminary Activity on Maximal Motor Performance

Abstract

This study assessed the effect of five selected treatments of preliminary activity on performance in the 60-yard dash, the cricket ball throw for distance, the jump reach, and the bicycle ergometer test of leg speed. The effect of such preliminary activity at different levels of achievement in the same performance tests was also investigated. An experimental sample of 15- to 17-year-old schoolboys (N = 45) underwent a testing program involving four consecutive days, with two sessions daily. On the basis of measures of pretreatment status, the subjects were matched into groups and subsequently exposed to the treatments. The treatments included identical maximal, identical submaximal, general strengthening, general flexibility and control routines. The statistical analysis of the results involved analysis of variance techniques. There was no evidence available indicating either that the treatments had an effect on the chosen motor performances or that there was a difference in this response at certain levels of achievement. As no measures of physiological function were taken, an assessment of the likely reasons for these findings could not be made.     

Body Fatness and Motor Performance During Preadolescence

Abstract

Performance differences between males and females have been attributed to both biological and cultural factors, although the relative significance of each has not been ascertained. Differences in body fatness between males and females has been frequently mentioned as one biological factor responsible for variations in physical performance. In children, it has been shown that boys exhibit slightly higher performance levels than girls until adolescence, when the differences favoring the boys become greater. The purpose of this study was to investigate the relationship between selected physical performance tests and body fatness in preadolescent boys and girls. Measures of age, height, weight, skinfold thicknesses at two sites, and performance scores on the vertical jump, standing broad jump, modified pullup, 40-yard dash, and 400-yard run were obtained on 563 elementary school children. The results of a one-way ANOVA indicated that there was a significant difference between boys and girls on all of the physical performance tests. Although the boys were slightly taller and heavier and scored better than the girls on the performance tests, there was no significant difference between the sexes in the sum of two skinfolds. Separate regression equations for the sum of two skinfolds by performance on each test indicated that, with the exception of the modified pullup test, body fatness was only marginally related to performance. These findings indicated that, although inversely related to the ability to move the total body weight, body fatness was of minimal importance in explaining performance differences between young boys and girls.