National Athletic Trainers\u27 Association Position Statement: Evaluation of Dietary Supplements for Performance Nutrition

Objectives: To help athletic trainers promote a food-first\u27 philosophy to support health and performance, understand federal and sport governing body rules and regulations regarding dietary supplements and banned substances, and become familiar with reliable resources for evaluating the safety, purity, and efficacy of dietary supplements. Background: The dietary supplement industry is poorly regulated and takes in billions of dollars per year. Uneducated athletes need to gain a better understanding of the safety, eligibility, and efficacy concerns associated with choosing to take dietary supplements. The athletic trainer is a valuable athletic team member who can help in the educational process. In many cases, athletic trainers are asked to help evaluate the legality, safety, and efficacy of dietary supplements. For this position statement, our mission is to provide the athletic trainer with the necessary resources for these tasks. Recommendations: Proper nutrition and changes in the athlete\u27s habitual diet should be considered first when improved performance is the goal. Athletes need to understand the level of regulation (or lack thereof) governing the dietary supplement industry at the international, federal, state, and individual sport-participation levels. Athletes should not assume a product is safe simply because it is marketed over the counter. All products athletes are considering using should be evaluated for purity (ie, truth in labeling), safety, and efficacy

Effects of beta-hydroxy-beta-methylbutyrate (HMB) on exercise performance and body composition across varying levels of age, sex, and training experience: A review

The leucine metabolite beta-hydroxy-beta-methylbutyrate (HMB) has been extensively used as an ergogenic aid; particularly among bodybuilders and strength/power athletes, who use it to promote exercise performance and skeletal muscle hypertrophy. While numerous studies have supported the efficacy of HMB in exercise and clinical conditions, there have been a number of conflicting results. Therefore, the first purpose of this paper will be to provide an in depth and objective analysis of HMB research. Special care is taken to present critical details of each study in an attempt to both examine the effectiveness of HMB as well as explain possible reasons for conflicting results seen in the literature. Within this analysis, moderator variables such as age, training experience, various states of muscle catabolism, and optimal dosages of HMB are discussed. The validity of dependent measurements, clustering of data, and a conflict of interest bias will also be analyzed. A second purpose of this paper is to provide a comprehensive discussion on possible mechanisms, which HMB may operate through. Currently, the most readily discussed mechanism has been attributed to HMB as a precursor to the rate limiting enzyme to cholesterol synthesis HMG-coenzyme A reductase. However, an increase in research has been directed towards possible proteolytic pathways HMB may operate through. Evidence from cachectic cancer studies suggests that HMB may inhibit the ubiquitin-proteasome proteolytic pathway responsible for the specific degradation of intracellular proteins. HMB may also directly stimulate protein synthesis, through an mTOR dependent mechanism. Finally, special care has been taken to provide future research implications

Optimal depth jump height quantified as percentage of athlete stature

Purpose: An individual’s optimal depth jump platform height provides a resistive force which allows an athlete to rebound with substantial velocity resulting in maximum power exertion. The objective of this investigation was to show that the optimal platform height in a depth jump can be quantified as a percentage of individual body stature which can serve as measurable quantified value. Although athlete height is not highly correlated to power ability nor does a universal height exist, this value can provide a basis for a rehabilitation or strength and conditioning program. The desired intensity of a program can be prescribed as a percentage of the individual’s optimal drop height. Methods: Sixteen male participants (age = 21.7 ± 1.54 yrs., height = 177.7 ± 11.4 cm, mass = 77.7 ± 13.6 kg; mean ± SD) were tested in a depth jump through a range of platform heights based on percentage of the individual anthropometric data defined at 0-, 10-, 20-, 30-, 40-, and 50% of the participants’ stature using a 3-D motion capture system (Qualysis) and force plates (Bertec) to calculate power. Results: The optimal drop height was found to be 21.3 (±10.3)% of the participants’ heights for maximum peak power and 27.5 (±15.3)% for maximum average power. Conclusions: These results suggest that an individual optimal drop height does exist as a percentage of stature and could be applied to a rehabilitation or power-based training program using the drop height as a quantified basis allowing an athlete to gradually work toward their individual optimal drop height and exhibit maximum power. Keywords: Kinematics; Kinetics; Lower extremity assessment; Plyometrics; Power

The Efficacy of the Rapid Form Cervical Vacuum Immobilizer in Cervical Spine Immobilization of the Equipped Football Player

OBJECTIVE: To determine the effectiveness of the Rapid Form Cervical Vacuum Immobilizer in controlling the cervical spine movements of a football player wearing shoulder pads and a helmet. DESIGN AND SETTING: We used a 1-group, repeated-measures experimental design to radiographically assess cervical spine range of motion with and without the Rapid Form Cervical Vacuum Immobilizer. Two experimental conditions (with and without vacuum splint) were applied to 10 subjects in a repeated-measures design. Each subject was radiographed in cervical forward flexion, extension, and lateral flexion under each experimental condition. SUBJECTS: Ten healthy male subjects without a history of cervical spine pathology or abnormality volunteered for this study. MEASUREMENTS: Cervical forward flexion, extension, and lateral flexion range of motion were compared under both treatment conditions. Joint angles were determined by straightedge tangential lines drawn on the radiographs along the foramen magnum, inferior ring border of the atlas, and along the inferior tips of the 2nd through 7th vertebral bodies. The total range of motion was determined and compared with the treatment condition by multiple paired t tests. RESULTS: The Cervical Vacuum Immobilizer limited cervical spine range of motion in forward flexion, extension, and lateral flexion. The secondary statistical analysis for the effect size determined that each group had a large effect size, indicating that the power of the experimental or vacuum splint group was high. CONCLUSIONS: We found that the Cervical Vacuum Immobilizer limited cervical spine range of motion in forward flexion, extension, and lateral flexion. The Cervical Vacuum Immobilizer can be easily placed on an injured, fully equipped football player and serves to limit cervical spine range of motion while the athlete is immobilized and transported. Future research should determine how the Cervical Vacuum Immobilizer limits range of motion with the athlete immobilized to the spine board

Syndesmotic Ankle Sprains

This is the publisher's version, also found at http://ehis.ebscohost.com/ehost/detail?vid=6&sid=fe3de117-c5d9-48c3-b95e-254c84dd9356%40sessionmgr4&hid=17&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=s3h&AN=SPHS-79089

Nutrition practices and knowledge of college varsity athletes: a follow up

Contains fulltext : mmubn000001_200106546.pdf (publisher's version ) (Open Access)Promotor : A. Vendrik91 p