Effects of sodium bicarbonate ingestion on prolonged running performance and recovery in trained runners

Background: While the effects of sodium bicarbonate on buffering capacity have been repeatedly examined on short-term and high-intensity exercise performance, studies on prolonged endurance performances such as running are scarce. Thus, the purpose of this study was to investigate the effect of NaHCO3 (0.3 g/kgBW) ingestion 60-minutes prior to the prolonged running testing and recovery in trained runners. Methods: A total of 10 trained male runners (age: 20.70 +/- 1.10 years; weight: 61.30 +/- 6.20 kg; height: 166.10 +/- 3.70 cm; VO2max 58.43 +/- 5.62 mL/kg/min) were recruited in this study. Subjects undertook 1 preliminary testing and 2 experimental trials: Sodium Bicarbonate (SB) and Placebo (PLA) trials, which consisted of: (i) a 60-minutes Prolonged Exercise Testing (PET) (30-minutes of constant speed run at 65 % of VO2max followed by a self-selected speed of 30-minutes maximum distance run) and (ii) 30-minutes of the recovery period in randomized order. Data were analyzed using SPSS version 23 for Windows. Results: Subjects ran further during the SB trial than the PLA trial (5,233.60 +/- 524.70 m vs. 5,021.40 +/- 440.10 m; p=0.012) associated with a greater blood lactate level (5.66 +/- 1.09 mmol/L vs. 3.68 +/- 0.71 mmol/L). Ingestion of SB drinks significantly increased urine pH during PET and recovery period (p<0.01). During post-recovery, a greater decrease in blood lactate level was found in the SB trial (2.53 +/- 0.91 mmol/L; 55%) as compared to the PLA trial (2.17 +/- 0.50 mmol/L; 41%) (p<0.01). Conclusion: The ingestion of NaHCO3 (0.30 g/kgBW) 60-minutes prior to the PET improved prolonged running performance associated with a faster lactate removal rate during the 30-minutes recovery period.