Does beta-alanine increase training volume and reduce perceived effort? Original paper

Supplementation with beta-alanine can increase muscle carnosine content, improving skeletal muscle buffering capacity and subsequent muscular performance in the range of 60–240 seconds. Although some evidence suggests that beta-alanine can increase training volume and reduce rating of perceived exertion (RPE), evidence for its utility is mixed.

This 4-week randomized controlled trial assessed the effects of beta-alanine supplementation on total volume performed and RPE among 16 resistance-trained men. The participants, all of whom had 1RMs of at least 1.25x and 1x body weight on the back squat and bench press, respectively, and an average of 5.9 years of resistance training experience, were randomized to ingest either four 1.6-gram doses of beta-alanine daily (6.4 grams per day) or a placebo.

Both groups completed a 4-day-per-week, full-body resistance training program. Each workout consisted of seven exercises at three sets per exercise, with 60 seconds of rest between sets and 120 seconds of rest between exercises, and all sets completed to muscular failure.

The investigators calculated the volume load (sets X repetitions X external load) and calculated a weekly volume index (VI) by dividing the volume load by each participant's body weight. In addition, the participants reported their session RPEs ten minutes after each training session, and the investigators calculated both weekly RPE and an overall mean RPE for the entire intervention for both groups.

Only the beta-alanine group experienced an increase from baseline in weekly VI and a reduction from baseline in weekly RPE. Overall mean RPE was lower in the beta-alanine group than in the placebo group.

Despite the increase in training volume and reduction in RPE, it's unclear whether these differences would have led to meaningful differences between groups in strength or muscle gain. A longer study would be needed to investigate these outcomes.