Mark S. Juhn

Popular Sports Supplements and Ergogenic Aids

This article reviews the evidence-based ergogenic potential and adverse effects of 14 of the most common products in use by recreational and elite athletes today. Both legal and prohibited products are discussed. This is an aggressively marketed and controversial area of sports medicine worldwide. It is therefore prudent for the clinician to be well versed in the more popular supplements and drugs reputed to be ergogenic in order to distinguish fact from fiction.Antioxidants, proteins and amino acids are essential components of diet, but additional oral supplementation does not increase endurance or strength. Caffeine is ergogenic in certain aerobic activities. Creatine is ergogenic in repetitive anaerobic cycling sprints but not running or swimming. Ephedrine and pseudoephedrine may be ergogenic but have detrimental cardiovascular effects. Erythropoietin is ergogenic but increases the risk of thromboembolic events. β-Hydroxy-β-methylbutyrate has ergogenic potential in untrained individuals, but studies are needed on trained individuals. Human growth hormone and insulin growth factor-I decrease body fat and may increase lean muscle mass when given subcutaneously. Pyruvate is not ergogenic. The androgenic precursors androstenedione and dehydroepiandrosterone have not been shown to increase any parameters of strength and have potentially significant adverse effects. Anabolic steroids increase protein synthesis and muscle mass but with many adverse effects, some irreversible. Supplement claims on labels of product content and efficacy can be inaccurate and misleading.

Oral creatine supplementation: separating fact from hype.

Many athletes-especially those participating in sports that emphasize strength-are taking oral creatine. Creatine supplements appear to enhance performance in repeated short bursts of stationary cycling and weight lifting, but the data on running, swimming, and single cycle sprints are not convincing of an ergogenic effect. Commonly reported side effects include muscle cramping, GI disturbances, and renal dysfunction, but creatines effect on the heart, brain, reproductive organs, and other organs has yet to be determined. Comprehensive studies with larger samples and crossover design are needed. If patients decide to take oral creatine, physicians need to provide guidance for proper dosing as well as education about potential harmful effects.

Manual Physical Therapy and Exercise Helpful for Knee Osteoarthritis

gles were calculated for cyclists on each type of bicycle in relation to the ground. Analysis of seat angles and vector forces gave estimates of stress; a tendency toward hyperextension of the pelvic/spinal angle resulted in the tensile forces at the promontorium with normally positioned seats. These forces could be reduced with an appropriate anterior tilt {10° to 15°) of the seat. These findings were used to modify seat tilt for member cyclists who had low-back pain. Forty members (both male and female; no ages given) with intermediateintensity low-back pain were divided into two groups (20 members each) and cycled with seats that had an anterior angle of inclination of either 10° or 15°. (An angle of greater than 15° caused discomfort and slipping from the seat.) The cyclists were seen again after 6 months of cycling and questioned about back pain. Seventy-two percent reported improvement in the incidence and magnitude of pain, and 20% reported

Getting Patients Up and Exercising

‘Best of the Literature’ presents summaries of sports medicine-related articles culled from more than 30 medical journals. Experts comment on what the new findings add to current medical thinking and on the implications for practice.

Glucosamine May Slow Osteoarthritis Progression

‘Best of the Literature’ presents summaries of sports medicine—related articles culled from more than 30 medical journals. Experts comment on what the new findings add to current medical thinking and on the implications for practice.