Carbohydrate mouth rinsing decreases perception of effort but does not enhance the performance of older male runners

• Published in: German journal of exercise and sport research Vol. 53; no. 3; pp. 301 - 308
• Main Authors: Azevedo, Paulo H. S. M., Pereira, Rafael, Fontes, Raysa, Leite, Mateus O., Koch, Alexander J., Machado, Marco
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2023
• Subjects: Biomedical and Life Sciences; Life Sciences; Main Article; Sport Education and Didactics; Sport Science; Aging; Ergogenic; Physical performance; Bayesian analysis; Deception
• ISSN: 2509-3142; 2509-3150
• DOI: 10.1007/s12662-022-00869-0

Purpose Endurance performance has been enhanced both by carbohydrate mouth-rinsing (CHO-MR) and allowing subjects to view an artificially slowed clock. Taste sensitivity and perception of time are altered in older men. We assessed the effects of CHO-MR and clock manipulation (ClkM) on running performance and ratings of perceived exertion (RPE) in older men. Methods Nine male runners (age 63 ± 3 years; ≥ 2 years of experience in ≥ 10 km run) completed six time-trial runs (~60 min each). While running, subjects viewed a chronometer running at real (NOR, total time = 60 min), 10% slower (SLO, total time = 66 min) or 10% faster (FAST, total time = 54 min) speeds. Before and at the midpoint of each run, subjects’ mouths were rinsed for 10 s with 25 mL of either a 6% maltodextrin solution (CHO) or an identically flavored aspartame solution (PLA) in a randomized, counterbalanced, double-blind fashion. Mean running velocity was recorded and RPE was assessed every 10 min. Data were analyzed using repeated measures for treatment (CHO-MR and time) over time. A Bayes factor analysis (BF10) was performed to quantify the probability for CHO-MR and/or ClkM to impact mean running velocity, RPE, and RPE/velocity ratio. Results CHO-MR did not alter running velocity compared with PLA, regardless of ClkM. Repeated measures analysis of variance (ANOVA) indicated CHO-MR significantly lowered RPE and RPE/velocity, and BF10 for RPE indicated high (64–99%) probabilities of RPE being affected by CHO vs. PLA. Conclusions ClkM does not influence endurance performance in older men. CHO-MR reduces RPE during long endurance running but has no impact on running speed.