1. Among the most popular nutritional supplements marketed to enhance muscle mass are chromium, creatine, vanadyl sulfate, boron, beta-hydroxy-beta-methyl butyrate (HMB), protein powders, and amino acids. 2. Chromium is a trace mineral that potentiates the effects of insulin. Well-controlled studies found that chromium supplements did not increase muscle mass. 3. Creatine, found in meat, has been shown to increase body weight in some individuals. The short-term increase in weight appears to be due to water retention, but researchers are currently investigating the possibility that longer-term weight gain might be due to greater accumulation of muscle protein. 4. Vanadium is a non-essential trace mineral that supposedly has insulin-like effects. It has not been found to increase muscle mass. Boron is a non-essential trace mineral whose function is not clear; it does not increase muscle mass. 5. HMB is a metabolite of the amino acid leucine. One study found that HMB increased muscle mass and strength and reduced muscle breakdown during resistance training. Additional research is needed to determine if these results can be duplicated and to address possible mechanisms and safety considerations. 6. Protein supplements are not needed to build muscle mass because sufficient protein (1.4 to 1.8 g of protein/kg/d) can be obtained through the diet. Although the "high tech" protein supplements include a variety of additives purported to boost weight gain, most have never been tested to evaluate their efficacy. 7. Research demonstrates that gains in muscle mass and strength occur when a well-nourished athlete (i.e., adequate energy and dietary protein) engages in a well-designed strength-training program.
© Copyright 1998 Alle Rechte vorbehalten.