Effects of Sodium Bicarbonate Supplementation with Acute Caffeine Ingestion on Simulated 3-KM Cycle Performance

Abstract

Sodium bicarbonate (SB) has been reported to increase extracellular pH and base excess after supplementation. This can delay the onset of fatigue and maintain a more favorable pH for ongoing glycolytic metabolism. Enhanced performance is also associated with caffeine (CAFF) as mediated through the CNS and periphery. There is limited information about the combined use of these two ergogenic aids. PURPOSE: To examine the effects of short-term SB supplementation combined with acute CAFF ingestion on simulated time trial (TT) performance and blood lactate (BL) accumulation in trained male cyclist's. METHODS: Male volunteers (n=16, 38.25 + 5.25 yrs, 60.39 + 5.97 ml/kg/min), in a double-blind, placebo (PL) controlled, crossover protocol, were randomly assigned four treatments (SB+CAFF, CAFF, SB, PL). Subject's personal bicycles were mounted to a stand with a PowerTap SL+ hub, computer, and PowerTap coded heart rate monitor. Day 1 subject's ingested 0.3 g/kg body weight (BW) either (SB) or (PL) in four equal doses. The final dose was taken two hours before TT. Day 2, one hour prior to TT, subjects ingested 6 mg/kg BW either CAFF or PL. After a 15 minute warm-up subjects performed a simulated 3-km TT. Finger prick BL samples were taken prior to and one hour post ingestion of CAFF or PL. Post TT, BL samples were taken immediately after exercise then and at three and ten minutes postexercise. During each TT, time to complete 3-km was measured in addition to average and peak values for power, speed, and heart rate. Data was analyzed using one-way ANOVA (p< 0.05). RESULTS: Mean TT was fastest with SB+CAFF (300.25 + 33.14s), followed by CAFF (306.00 + 31.98s), SB (311.19 + 32.47s) and PL (316.00 + 32.02s). Three minutes post TT, BL concentrations for SB+CAFF (13.72 + 1.92 mmol/L, p<0.05) were higher than PL (11.56 + 0.07 mmol/L, p<0.05). At 10 minutes post TT, BL concentrations were higher for SB+CAFF (11.99 + 2.52 mmol/L, p<0.05) than CAFF (8.15 + 2.09mmol/L, p<0.05), SB (8.99 + 1.97 mmol/L, p<0.05) or PL (7.92 + 2.13 mmol/L, p<0.05). CONCLUSIONS: These data show a potential for performance enhancement through the combined supplementation of CAFF and SB as well as significantly higher postexercise BL concentrations.