Authors
Jamil Jafari Pouresmaeili, Department of Exercise Physiology, Kharazmi University, Iran
Saied Jalal Aboodarda, Faculty of Kinesiology, University of Calgary, Calgary, Canada
Hamid Rajabi, Department of Exercise Physiology, Kharazmi University, Iran
International Journal of Exercise Science 19(2): 2005, 2026.
Abstract
Sodium bicarbonate (SB) and beta-alanine (BA) can enhance high-intensity exercise performance. This study examined the effects of eight weeks of resistance training combined with these supplements on muscle cross-sectional area (CSA), serum myostatin and interleukin-15 concentration, and upper- and lower-body muscular strength and power. Twenty active males (age: 18-35) were divided into supplement (SUP) and placebo groups (PL; each group n=10). Participants undertook eight weeks of supervised resistance training, including 3 sessions × 3 sets × maximum repetitions at 70% of 1RM. Supplementations included 3- 6 g/day BA and 4-6 g/day SB administered for 8 weeks. Exercise volume, calculated as the total number of repetitions completed in each session, increased to a greater extent following SUP (~29%) than PL (~13%) groups (P=0.014). Central segment of quadriceps CSA, measured using magnetic resonance imaging, demonstrated a greater increase following SUP compared to PL for both right ((~21%; pre to post: 452.47±55.98 to 548.21±73.92 mm3) vs. PL (~5%; 443.81±28.74 to 466.42±31.91 mm3)) and left ((~24%, 456.81±59.77 to 566.71±82.62 mm2) vs. PL (~9%; 438.12±41.54 and 479.06±49.91 mm3)) legs (all P<0.01). However, interleukin-15 concentrations decreased following both conditions (time effect: P<0.001). Also, no difference was observed between groups for the increased 1-RM squat, bench press, and countermovement jump (time effects: P<0.05). The results suggest that co-ingestion of BA and SB may enhance the central segment of the CSA in the quadriceps muscle, possibly by increasing exercise volume. This could be a potential approach in promoting muscle hypertrophy in athletic and clinical rehabilitation settings.