Dietary Supplement Use Among Endurance Athletes

Existing surveys of dietary supplement use among the general population suggest that 50‐75% of adult Americans are "regular users" of dietary supplements. Use among athletes is less clear, with some reports indicating 100% usage among bodybuilders, and other estimates indicating 30‐50% usage among endurance athletes. We examined dietary supplement usage patterns among a sample of 326 triathletes ‐ 176 "Ironman" distance (IM, 71 females, 103 males) and 152 "Olympic" distance (OD, 63 females, 89 males) via a 50‐question survey. Results showed that triathletes at both OD and IM distances are avid users of dietary supplements (d/wk usage = 6.1d IM / 4.5 OD), with IM using more supplements for "recovery" (+20%) and "endurance" (+22%) and also greater use "after" exercise (+35%), compared to OD. Primary sources of information about supplements comes from Friends and Training Partners (89% IM/83% OD), the Internet (92% IM/95% OD), and Coaches/Trainers (65% IM/53% OD). A high percentage of triathletes indicated difficulty finding accurate information (88‐90%) and wanting more information (89‐90%) about supplements. These data show a high usage of dietary supplements among competitive triathletes, as well as a desire for additional information regarding their use. Future research is warranted to elucidate how to best educate endurance athletes about the pros and cons of dietary supplements usage.