Ergogenic dietary aids for the elderly.

Ergogenic dietary aids might be useful adjunctive therapy to enhance the effects of exercise in the elderly, who lose physical function with age. Many such aids have been tested in athletes and untrained younger persons in laboratory and athletic performance settings, with positive results, although not all studies have demonstrated benefit. Some substances have been tested in the elderly, including creatine, caffeine, β-hydroxy-β-methylbutyrate, ubiquinone, and carnitine. The published medical evidence for the use of these substances is considered in this review article. All studies have involved a few subjects for a short period. Studies of creatine alone or together with exercise in old persons have yielded mixed results. These studies have confirmed that creatine in older individuals, as in younger individuals, can increase the short-term capacity to perform quick, repeated episodes of intense activity. An investigation of caffeine has suggested that in older as in younger individuals, caffeine increases endurance but may not improve other parameters of exercise capacity. Evidence has implied β-hydroxy-β-methylbutyrate can increase the ability to perform certain short-term activities requiring strength, but not others. Carnitine has been reported to decrease fatigue and increase endurance in older persons. An investigation of ubiquinone has shown no benefit. Further testing has involved the combinations of agents, such as creatine and caffeine, and combinations of β-hydroxy-β-methylbutyrate, showing some small improvements in physical function. Future research with these and potentially other combinations over a longer duration will be needed to establish the safety and efficacy of ergogenic dietary aids.