Abstract
PURPOSE: In recent years, there has been a rise in the popularity of zero sugar sports drinks which contain fewer calories (from reduced carbohydrate (CHO) content), while maintaining identical electrolyte content. However, substantial evidence demonstrates that CHO consumption before or during exercise enhances performance and supports recovery. Because zero-sugar sports drinks contain only a fraction of the carbohydrate found in traditional full-sugar formulations, they may be less effective for supporting recovery and subsequent performance following muscle-fatiguing exercise. This study investigates whether consuming a full sugar (CHO+), a zero-sugar (CHO-), or water drink following lower-body muscle fatiguing exercise improves cycling time to exhaustion (TTE). We hypothesize that CHO+ will result in better performance and recovery measures than CHO- and water. METHODS: Active male participants (n=7; age 25.33±5.47 y; VO2max 41.69±7.91 mL/kg/min) visited the lab four times, with each visit separated by at least one week. The first visit consisted of completing physical activity questionnaires, a DXA scan, and a cycling VO2max test. Visits 2-4 were completed in a randomized, crossover design. Briefly, participants arrived at the Applied Physiology Lab following an overnight fast and completed an exhaustive lower body exercise protocol (interval cycling sprints, body weight squats, lunges, box step-ups, and Romanian Deadlifts). Immediately post-exhaustive exercise, lactate was measured, and participants consumed 20oz (591 mL) of a CHO+, CHO-, or water drink. Thirty minutes later, participants completed a cycling TTE test at 70% Wmax, and another fingerstick lactate measurement was done 2-min and 5-min post exercise. Data were analyzed using a repeated measures one-way ANOVA. RESULTS: There were no differences in time to exhaustion between beverage types (CHO+: 11.54±4.89 min; CHO-: 11.29±3.22 min; Water: 11.43±4.07 min; P=0.99). There were no differences in blood lactate following the TTE test (CHO+: 9.35±2.11 mmol·L⁻¹; CHO-: 9.55±3.3 mmol·L⁻¹; Water 9.13±3.66 mmol·L⁻¹; P=0.93). CONCLUSION: Contrary to our hypothesis, no significant differences in TTE were observed between beverage conditions. Given the short recovery period and likely residual metabolic fatigue from the exhaustive protocol, subsequent performance may have been limited by factors other than carbohydrate availability. Data collection remains ongoing.
Recommended Citation
Moody, Ross; Cipriano, Nicole; Coles, Macilynn E.; Stephens, Jason; and Deemer, Sarah
(2026)
"Carbohydrate Effects on Cycling Time to Exhaustion Following Exercise-Induced Glycogen Depletion: Preliminary Data,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
Iss.
18, Article 218.
Available at:
https://digitalcommons.wku.edu/ijesab/vol2/iss18/218