Abstract:
Three studies examined hydration and performance for recreational exercisers (REC). Three beverages (flavored caloric (CE) and non-caloric (NCE) electrolyte-containing sport drinks and water (W)) were served to male (n = 24) and female (n = 14) REC in a counter-balanced order during 1-h of moderate intensity cycling (mean ± SD heart rate = 146 ± 4 beats/min) in an environment of 25° C wet bulb globe temperature. The volume of beverage served was equal to sweat loss measured (mean ± SE = 834 ± 59 mL) in a familiarization trial with no fluid intake during exercise. No differences (p > .05) among beverages were found in: performance (peak and mean power) during a set of three Wingate Anaerobic Tests completed after cycling, perceived exertion, or mood states among beverages. After exercise in the familiarization trial with no fluid intake, participants drank ad libitum for 30 min with all beverages available. Consumption volume among beverages did not differ (p > .05). Participants reported that replacing 100% of sweat loss was an appropriate volume and did not result in stomach discomfort for the majority of individuals in fluid intake during exercise sessions. Total intake in the familiarization session when fluids were consumed in recovery only (mean ± SD, 971 ± 375 mL) was less (p < .001) than when consumed during both exercise and recovery (W (1,415 ± 560 mL,), NCE (1,244 ± 538 mL, p < .001), and CE (1,196 ± 444 mL), and W was greater than CE (p = .01)). The survey found decreased performance (69%) and heat-illness (45%) believed to be related to dehydration among runners was very common. Almost all (94%) of participants (n = 276) reported drinking during outdoor runs in warm weather. Faster higher volume runners believed that consuming sport beverages would result in improved performance and better hydration than water. For REC exercising for ~1 h, replacing sweat loss during exercise and drinking ad libitum afterwards, should result in a fluid intake level that will return body mass close to pre-exercise level, be tolerable, and result in no decrease in performance when W or CE are used instead of CE.
