Post-prandial carbohydrate ingestion during 1-h of moderate-intensity, intermittent cycling does not improve mood, perceived exertion, or subsequent power output in recreationally-active exercisers

Journal of the International Society of Sports Nutrition, Jan 2013

Background This study compared the effects of ingesting water (W), a flavored carbohydrate-electrolyte (CE) or a flavored non-caloric electrolyte (NCE) beverage on mood, ratings of perceived exertion (RPE), and sprint power during cycling in recreational exercisers. Methods Men (n = 23) and women (n = 13) consumed a 24–h standardized diet and reported 2–4 h post-prandial for all test sessions. After a familiarization session, participants completed 50 min of stationary cycling in a warm environment (wet bulb globe temperature = 25.0°C) at ~ 60-65% of heart rate reserve (146 ± 4 bpm) interspersed with 5 rest periods of 2 min each. During exercise, participants consumed W, CE, or NCE, served in a counterbalanced cross-over design. Beverage volume was served in 3 aliquots equaling each individual’s sweat losses (mean 847 ± 368 mL) during the familiarization session. Profiles of Mood States questionnaires (POMS) were administered and blood glucose levels were determined pre- and post- sub-maximal cycling. Following sub-maximal exercise, participants completed 3 30–s Wingate anaerobic tests (WAnT) with 2.5 min rest between tests to assess performance. Results Blood glucose was higher (p <  0.05) after 50 min of submaximal cycling just prior to the WAnT for CE (6.1 ± 1.7 mmol/L) compared to W (4.9 ± 1.5 mmol/L) and NCE (4.6 ± 1.2 mmol/L). Nonetheless, there were no differences among treatments in peak (642 ± 153, 635 ± 143, 650 ± 141 watts for W, NCE, and CE, respectively; p  =  0.44) or mean (455 ± 100, 458 ± 95, 454 ± 95 watts for W, NCE, and CE, respectively; p = 0.62) power for the first WAnT or mean (414 ± 92, 425 ± 85, 423 ± 82 watts, respectively; p = 0.13) power output averaged across all 3 WAnT. Likewise, RPE during submaximal exercise, session RPE, and fatigue and vigor assessed by POMS did not differ among beverage treatments (p > 0.05). Conclusions Carbohydrate ingestion consumed by recreational exercisers during a 1–h, moderate-intensity aerobic workout did not alter mood or perceived exertion, nor did it affect subsequent anaerobic performance under the conditions of this study. Drinking caloric sport beverages does not benefit recreational exercisers in a non-fasted state.

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Post-prandial carbohydrate ingestion during 1-h of moderate-intensity, intermittent cycling does not improve mood, perceived exertion, or subsequent power output in recreationally-active exercisers

Eric K O'Neal 0 1 Sylvia P Poulos 2 Jonathan E Wingo 1 Mark T Richardson 1 Phillip A Bishop 1 0 Current address: Department of Health , Physical Education, and Recreation , University of North Alabama , Florence, AL 35632 , USA 1 Department of Kinesiology, The University of Alabama , Tuscaloosa, AL , USA 2 Global Research, The Coca-Cola Company , Atlanta, GA 30313 , USA Background: This study compared the effects of ingesting water (W), a flavored carbohydrate-electrolyte (CE) or a flavored non-caloric electrolyte (NCE) beverage on mood, ratings of perceived exertion (RPE), and sprint power during cycling in recreational exercisers. Methods: Men (n = 23) and women (n = 13) consumed a 24-h standardized diet and reported 2-4 h post-prandial for all test sessions. After a familiarization session, participants completed 50 min of stationary cycling in a warm environment (wet bulb globe temperature = 25.0C) at ~ 60-65% of heart rate reserve (146 4 bpm) interspersed with 5 rest periods of 2 min each. During exercise, participants consumed W, CE, or NCE, served in a counterbalanced cross-over design. Beverage volume was served in 3 aliquots equaling each individual's sweat losses (mean 847 368 mL) during the familiarization session. Profiles of Mood States questionnaires (POMS) were administered and blood glucose levels were determined pre- and post- sub-maximal cycling. Following sub-maximal exercise, participants completed 3 30-s Wingate anaerobic tests (WAnT) with 2.5 min rest between tests to assess performance. Results: Blood glucose was higher (p < 0.05) after 50 min of submaximal cycling just prior to the WAnT for CE (6.1 1.7 mmol/L) compared to W (4.9 1.5 mmol/L) and NCE (4.6 1.2 mmol/L). Nonetheless, there were no differences among treatments in peak (642 153, 635 143, 650 141 watts for W, NCE, and CE, respectively; p = 0.44) or mean (455 100, 458 95, 454 95 watts for W, NCE, and CE, respectively; p = 0.62) power for the first WAnT or mean (414 92, 425 85, 423 82 watts, respectively; p = 0.13) power output averaged across all 3 WAnT. Likewise, RPE during submaximal exercise, session RPE, and fatigue and vigor assessed by POMS did not differ among beverage treatments (p > 0.05). Conclusions: Carbohydrate ingestion consumed by recreational exercisers during a 1-h, moderate-intensity aerobic workout did not alter mood or perceived exertion, nor did it affect subsequent anaerobic performance under the conditions of this study. Drinking caloric sport beverages does not benefit recreational exercisers in a non-fasted state. - Background Multiple investigations have found ingestion of carbohydrate-electrolyte beverages (CE) before or during exercise improves performance during high-intensity, continuous endurance exercise lasting 1 h or less [1-11] and during intermittent, high-intensity exercise simulating sports such as soccer or basketball lasting approximately 1 h [12,13]. The mechanisms for performance improvements related to CE consumption during shorter-bout activity are not well understood. Multiple investigations in which rinsing a carbohydrate-containing solution in the mouth without ingestion improves performance lasting 1 h or less [14-18] has led to a hypothesis suggesting that performance enhancement may be linked to centrally mediated factors involving receptors in the oral cavity associated with reward and locomotion centers that are activated when carbohydrates are sensed in the mouth [16]. Additional evidence suggesting decreased perceived exertion and alterations in mood from CE use can also be found. Backhouse et al. [19] found that cyclists reported higher levels of pleasure beginning at 15 min and persisting during a 2-h ride when consuming a CE versus an artificially sweetened placebo. Similarly, Rollo et al. [15] found runners reported greater feelings of pleasure in the first 5 minutes of a 30-min run at a selfselected pace with a CE mouth rinse versus a placebo. Additionally, in two studies [12,13] in which participants consumed CE during intermittent high intensity exercise for 1 h tended to report less fatigue and more vigor late in exercise compared to artificially sweetened placebos. Lower rate of perceived exertion (RPE) was also noted when cyclists consumed a carbohydrate beverage versus placebo during a 50 min of high intensity cycling followed by a Wingate Anaerobic Test [5]. The reputed benefits of CE ingestion described above may be related, in part, to study design. In a review of the literature concerning the efficacy of commercially available CE, Coombes and Hamilton [20] noted that studies supporting the use of CE for improved performance during prolonged endurance exercise frequently included participants exercising after a 12-h fast. Similar conditions were found for the majority of the ~ 1h duration studies cited above in which positive results were found for carbohydrate beverages [2,4-9,11-15,17]. Of the 17 studies reviewed in this current paper, fi (...truncated)


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Eric K O’Neal, Sylvia P Poulos, Jonathan E Wingo, Mark T Richardson, Phillip A Bishop. Post-prandial carbohydrate ingestion during 1-h of moderate-intensity, intermittent cycling does not improve mood, perceived exertion, or subsequent power output in recreationally-active exercisers, Journal of the International Society of Sports Nutrition, 2013, pp. 4, 10, DOI: 10.1186/1550-2783-10-4