Sodium bicarbonate supplementation improves hypertrophy-type resistance exercise performance

The aim of the present study was to examine the effects of sodium bicarbonate (NaHCO₃) administration on lower-body, hypertrophy-type resistance exercise (HRE). Using a double-blind randomized counterbalanced design, 12 resistance-trained male participants (mean ± SD; age = 20.3 ± 2 years, mass = 88.3 ± 13.2 kg, height = 1.80 ± 0.07 m) ingested 0.3 g kg⁻¹ of NaHCO₃ or placebo 60 min before initiation of an HRE regimen. The protocol employed multiple exercises: squat, leg press, and knee extension, utilizing four sets each, with 10–12 repetition-maximum loads and short rest periods between sets. Exercise performance was determined by total repetitions generated during each exercise, total accumulated repetitions, and a performance test involving a fifth set of knee extensions to failure. Arterialized capillary blood was collected via fingertip puncture at four time points and analyzed for pH, [HCO₃ ⁻], base excess (BE), and lactate [Lac⁻]. NaHCO₃ supplementation induced a significant alkaline state (pH: NaHCO₃: 7.49 ± 0.02, placebo: 7.42 ± 0.02, P < 0.05; [HCO₃ ⁻]: NaHCO₃: 31.50 ± 2.59, placebo: 25.38 ± 1.78 mEq L⁻¹, P < 0.05; BE: NaHCO₃: 7.92 ± 2.57, placebo: 1.08 ± 2.11 mEq L⁻¹, P < 0.05). NaHCO₃ administration resulted in significantly more total repetitions than placebo (NaHCO₃: 139.8 ± 13.2, placebo: 134.4 ± 13.5), as well as significantly greater blood [Lac⁻] after the exercise protocol (NaHCO₃: 17.92 ± 2.08, placebo: 15.55 ± 2.50 mM, P < 0.05). These findings demonstrate ergogenic efficacy for NaHCO₃ during HRE and warrant further investigation into chronic training applications.