SODIUM BICARBONATE IMPROVES INTENSE EXERCISE ADAPTATION IN FEMALES

Edge, J., Bishop, D., & Goodman, C. (2004). Chronic sodium bicarbonate ingestion affects training adaptations during severe exercise training. Medicine and Science in Sports and Exercise, 36(5), Supplement abstract 1410.

The purpose of this study was to determine the effects of sodium bicarbonate ingestion (NaHCO3) during training, on changes in severe intensity exercise tolerance and aerobic and anaerobic capacity. Active, but not well-trained females (N = 16), were tested on a graded exercise test to determine VO2peak and lactate threshold (LT). Forty-eight hours later, an exercise tolerance test (ET; total work completed at pre-training VO2peak intensity) was performed. Muscle biopsies (Vastus lateralis) were taken immediately before and after the exercise tolerance test to determine muscle metabolites, anaerobic yield of ATP, and muscle buffer capacity (Betam in-vitro). After initial testing, Ss were randomly assigned (matched on LT and ET) to one of two training groups. Each matched pair performed the same amount of total work, however the experimental group ingested NaHCO3, (0.4 g/kg) while the control group ingested a placebo (NaCl, 0.2 g/kg) prior to each training session. Training involved 6-12, 2-minute high-intensity intervals (140-180% LT; 1 min rest), 3 wk for 8 weeks.

Both groups significantly increased total work completed during the exercise tolerance test and lactate threshold test. However, the NaHCO3 group had significantly greater improvements than the NaCl group in total work and lactate threshold. Both groups also had significant improvements in Betam in-vitro and VO2peak, with no significant differences between groups.

Implication. Chronically inducing metabolic alkalosis and thereby altering the likely accumulation of H+ during severe-intensity exercise training, may beneficially affect both aerobic and anaerobic fitness adaptations. Post-training, the NaHCO3 group also had a significantly greater tolerance of severe-intensity exercise, despite training workloads being matched between groups.

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