Effects of Sodium Citrate Ingestion on Exercise Performance at Moderate Altitude

Abstract

1173 Sodium citrate has been used as a potential ergogenic aid for improving high-intensity exercise performance. To date, few studies have looked at whether sodium citrate is effective at improving high-intensity exercise performance at altitude. PURPOSE: The purpose of this study was to examine the effect of sodium citrate ingestion and moderate altitude exposure on high-intensity exercise performance. METHODS: Six healthy, active subjects (mean age = 24.8 ± 10.4 yr) were tested at sea level (SL1), upon acute exposure to 3400 m (ALT1), two weeks following acclimatization at 3400 m (ALT2), and upon return to sea level (SL2). Each subject performed a cycle ergometer exercise protocol corresponding to approximately 110% of their VO2 max until exhaustion. The protocol was performed twice under each condition, once after ingestion of a placebo, and once after ingestion of a sodium citrate drink (.4 gms of sodium citrate per kg of body weight in 500 ml of water). Time duration to exhaustion and changes in blood lactate levels post-exercise were measured. RESULTS: There were no significant increases (p>0.05) in time to exhaustion at ALT 1 for the placebo (144.5 ± 43.8 sec) compared to the sodium citrate condition (149.2 ± 27.0 sec) or at any of the other three (SL1, ALT2, SL2) conditions. Blood lactate levels during ALT2 were significantly increased (p<0.05) relative to SL1 (8.62 mmol ± 5.43 with placebo vs. 13.78 mmol ± 4.21 with sodium citrate ingestion). Under all other conditions, no significant blood lactate differences were observed. Some gastrointestinal distress was also experienced as a side effect of sodium citrate ingestion. CONCLUSION: It would therefore appear that under all four conditions explored, sodium citrate had no significant effect on high-intensity exercise performance. It should be noted however, that differences in time to exhaustion experienced during the ALT1, ALT2, and SL2 conditions, while not statistically significant, could be great enough to cause an improvement in athletic performance.