Caffeine Supplementation or Carbohydrate Mouth Rinse Improves Performance.
Study Goal
The researchers aimed to determine whether carbohydrate mouth rinse improves performance (total repetitions) and reduces perceived exertion during resistance training in physically active women.
Results Summary
Carbohydrate mouth rinse significantly improved total repetitions in both lower and upper limb exercises compared to placebo, with no difference in perceived exertion. No additional benefit was observed when combined with caffeine.
Population
29 physically active women (age 24±4 years, weight 60.0±7.9 kg, height 161.0±6.0 cm).
Effective Dosage
6 g of maltodextrin rinsed for 10 seconds.
Duration
Acute (single-dose intervention during strength training sessions).
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
caffeine supplementation | increase | total repetitions for both lower and upper limb exercises | physically active women | P<0.01; BF10 ~99% | showed significant improvement | #1 |
carbohydrate mouth rinse | increase | total repetitions for both lower and upper limb exercises | physically active women | P<0.01; BF10 ~99% | showed significant improvement | #2 |
caffeine plus carbohydrate | increase | total repetitions for both lower and upper limb exercises | physically active women | P<0.01; BF10 ~99% | showed significant improvement | #3 |
caffeine supplementation | decrease | rate of perceived exertion | physically active women | BF10 analyses showed a higher probability | showed a higher probability of lower | #4 |
carbohydrate mouth rinse | no change | rate of perceived exertion | physically active women | P>0.05 | did not differ | #5 |
caffeine plus carbohydrate | no change | rate of perceived exertion | physically active women | P>0.05 | did not differ | #6 |
caffeine plus carbohydrate | no change | performance in resistance training | physically active women | - | no additional effect | #7 |
Training volume is one of the critical variables required to promote resistance training benefits (e. g., hypertrophy, muscular strength). Thus, strategies to improve training volume are required. We tested the hypothesis that there is an increase in performance and reduction in the rate of perceived exertion in strength training with caffeine supplementation, carbohydrate mouth rinse, and a synergistic effect of caffeine supplementation plus carbohydrate mouth rinse. We recruited 29 physically active women: 24±4 years, 60.0±7.9 kg, 161.0±6.0 cm. This study was a double-blind, randomized, placebo-controlled, and crossover one. The subjects performed all sessions of strength training under different conditions: caffeine (6.5 mg·kg-1 body mass); carbohydrate (6 g of maltodextrin rinsed for 10 s); caffeine plus carbohydrate; or placebo. We applied the ANOVA for repeated measures through the null-hypothesis statistical test, and the Bayes factors analyses approach. The subjects showed significant improvement in the total repetitions (P<0.01; BF10 ~99%) for both lower and upper limb exercises in all conditions compared to placebo without difference among interventions. The rate of perceived exertion (P>0.05) did not differ among interventions. However, BF10 analyses showed a higher probability of lower RPE for CAF intervention. We conclude that either caffeine supplementation or carbohydrate mouth rinse can improve performance in resistance training. There is no additional effect of caffeine plus carbohydrate.