Beta-alanine (BA) supplementation has gained attention for its potential ergogenic effects, particularly in resistance training contexts. This study investigates the specific impact of BA on isotonic strength endurance performance during advanced resistance training protocols known as drop-set and bi-set exercises.
Conducted as a double-blind parallel-group randomized controlled trial, the research involved 22 young resistance-trained individuals. Participants were divided into two groups: one receiving BA supplementation (6.4 g·day -1) and the other a placebo (maltodextrin). The study aimed to determine if BA could enhance performance metrics, specifically the total number of repetitions completed during the exercises, while also assessing psychological responses such as perceived exertion, motivation, and affect.
Study Design and Methods
After familiarization with psychological scales and strength tests, participants underwent drop-set and bi-set resistance training protocols before and after a 4-week supplementation period. The drop-set protocol involved three sets at 80% of their one-repetition maximum (1-RM), followed by three successive load reductions. The bi-set protocol consisted of three sets at 70% 1-RM, alternating between inclined and flat bench presses.
Outcomes were analyzed using mixed models for repeated measures, with statistical significance set at p < 0.05. The results indicated that the total number of repetitions significantly increased in both the drop-set (+17.3%, effect size [ES] = 0.74, p = 0.007) and bi-set (+18.2%, ES = 0.98, p < 0.0001) protocols for the BA group. In contrast, the placebo group showed no significant changes in performance metrics.
Psychological Responses
While the total number of repetitions improved with BA supplementation, psychological responses remained largely unaffected. Perceived exertion increased across sets during both training protocols (both p < 0.0001), but there were no significant differences between the BA and placebo groups (both p > 0.05). Other psychological factors, including motivation and affect, did not show significant changes across groups or time (all p > 0.05).
What this study does not show
This study does not establish a causal relationship between beta-alanine supplementation and improved psychological responses during resistance training, as no significant changes were observed in psychological metrics.
Evidence scorecard
- Analytic validity: established
- Clinical validity: established
- Clinical utility: established
The evidence is based on a randomized controlled trial involving human participants.