Carbohydrate Mouth Rinse following Fatiguing Resistance Exercise does not Improve Muscle Function

Abstract

PURPOSE: Carbohydrate mouth rinse has been shown to enhance the performance of endurance exercise. However, the effects of carbohydrate mouth rinse on other types of exercise, including strength and power exercises, have yet to be established. The primary purpose of this study was to assess the effect of carbohydrate mouth rinse on muscular performance after a fatiguing resistance exercise protocol. METHODS: Twenty-one, recreationally resistance trained participants (13 ♀, 8 ♂ Age: 22 ± 2 yr) completed a fatiguing resistance exercise protocol consisting of 8 lower and upper body exercises at 70% of their 1 RM. Volunteers completed the resistance exercise protocol on three occasions, followed by muscle function tests. In a double-blind, randomized, and counterbalanced fashion, each subject was tested under a control (CON) (no rinse), carbohydrate rinse (CHO) (25 ml of 6.4% maltodextrin solution), or placebo rinse (PLC) (non-caloric artificial sweetener placebo solution) condition. During each vertical jump, each attempt at maximal strength (1-RM), and each set of the muscular endurance tests for both the back squat and bench press exercises, subjects rinsed with a CHO or PLC solution for 10 to 15 seconds. ANOVAs were conducted to locate differences between conditions. RESULTS: There were no significant differences in vertical jump (CON = 46.8 ± 9.7, CHO = 48.7 ± 9.7, PLC = 48.0 ± 9.7 cm), maximal strength for back squat (CON = 85.0 ± 41.4, CHO = 87.7 ± 41.1, PLC = 86.6 ± 41.0 kg), and bench press (CON = 56.1 ± 35.7, CHO = 57.4 ± 35.3, PLC = 57.0 ± 35.1 kg) between conditions (p > 0.05). The number of repetitions performed during the back squat (CON = 48 ± 14, CHO = 53 ± 16, PLC = 50 ± 13 repetitions) and bench press (CHO = 44 ± 9, CHO = 49 ± 11, PLC = 48 ± 11 repetitions) muscular endurance tests also did not differ significantly between conditions (p > 0.05). CONCLUSION: Carbohydrate mouth rinsing following a fatiguing resistance exercise protocol does not affect muscular power, maximal strength, or muscular endurance performance.