Sodium bicarbonate, widely known as baking soda, is an important buffering system in acid-base homeostasis. Ingestion of sodium bicarbonate may be an effective ergogenic aid during short and long endurance events, as it has been shown to reduce blood lactate levels during these events.
PURPOSE: To examine the effectiveness of sodium bicarbonate on endurance (0.25 miles) climbing performance.
METHODS: Using a double blind, randomized, crossover experimental design, nine experienced (6 male & 3 female) rock climbers (20.3±0.82 (mean±SD) yr old, 63.1±14.24 kg; 173.2±11.09 cm, 48.1±4.79 ml·kg·min-1 VO2max, 9.99±5.27 % fat) participated in two experimental trials: one sodium bicarbonate and one placebo, separated by at least one week. Subjects refrained from moderate to heavy exercise for 48 h prior to the protocols. All testing started between 4:00PM and 5:00PM, 30 min after placebo and sodium bicarbonate ingestion and at least 3 hours after subjects’ lunch. Subjects completed a 33-lap (0.25 miles) time trial (TT) as fast as possible on an indoor route (rated as 5.6 on the Yosemite Decimal System Scale). Heart rate (HR) and rating of perceived exertion (RPE) were taken after each lap, and blood lactate levels were measured after each TT for comparison. The relationship between variables was determined using Pearson product moment correlations, and differences via paired, two-tailed t-test, with significance set at p<0.05.
RESULTS: The sodium bicarbonate trial did not yield significantly different time compared to the control, 27.72±8.29 min (mean ± SD) versus 28.83±8.59 min (p>0.05). Although blood lactate levels were significantly increased with both trials compared to baseline, there were no differences between the sodium bicarbonate trial 8.43±3.62 and control 9.40±3.04 mmol·L-1. During the TT, there was no significant trial by lap interaction for HR and RPE.
CONCLUSIONS: The results suggest that sodium bicarbonate ingestion does not improve TT times and has no effect on HR, RPE, and blood lactate responses in endurance indoor rock climbing.