Effects Of Transdermal Sodium Bicarbonate Lotion On High-intensity Cycling Performance

Abstract

Pre-exercise oral ingestion of sodium bicarbonate may lead to improved high-intensity exercise performance in trained individuals. However, this practice often causes gastrointestinal distress, which can mitigate the ergogenic benefits. An alternative method of administration involves the delivery of sodium bicarbonate through applying lotion to the surface of the skin surrounding the working muscles. However, few studies have examined the ergogenic benefits of this practice. PURPOSE: To examine the effects of pre-exercise application of a sodium bicarbonate lotion (SBL) on performance during a series of intermittent high-intensity cycling bouts compared to a placebo (PLA). METHODS: In a randomized cross-over fashion, 7 trained cyclists completed a one-hour cycling performance test on a stationary trainer using their personal road bikes on two separate occasions. This protocol consisted series of maximal 5-second (neuromuscular, NM), 5-minute (maximal aerobic, MAP), 20-minute (functional threshold, FTP), and 1-minute (anaerobic capacity, AC) efforts separated by recovery. Performance was determined by the mean power output during each effort. Thirty minutes prior, subjects applied 0.4 g/kg-bw of either SBL or PLA to the quadriceps, hamstrings, and gastrocnemius. Capillary samples were collected at 1-minute and 3-minutes following the MAP, FTP, and AC tests to measure blood lactate. Differences in power output and lactate responses between conditions were tested using Wilcoxon signed-rank tests. RESULTS: There were no differences in power output during the any of the efforts between conditions. In the SBL condition, participants had higher blood lactate concentrations one-minute following the MAP test compared to PLA (p = 0.01, mean dif. = 4.3 mmol/L). CONCLUSION: Our findings suggest that pre-exercise application of SBL did not influence performance in trained cyclists. The elevated blood lactate response to the MAP effort in SBL could indicate enhanced cellular buffering and lactate clearance. Practically, this suggests that SBL could be beneficial prior to shorter time-trials or intervals performed near maximal aerobic capacity. Once the target sample of 16 cyclists have completed the study, we can provide further insight on the ergogenic effects of SBL application in this population.