Oral Lactate Supplementation Does Not Affect Repeated Sprint Performance In Well Trained Cyclists

Lactate is now considered an important energy intermediate, signalling molecule, and metabolic buffer and may be ergogenic. Previous studies have explored the consequences of lactate supplementation on exercise performance; however, no studies have investigated the efficacy of oral lactate during a prolonged performance test which aims to simulate the stochastic nature of road race cycling. PURPOSE: To test if oral lactate supplementation is an effective dietary approach to enhance exercise performance and acid-base balance in trained cyclists during an exercise protocol devised to simulate the demands of endurance road-race cycling. METHODS: Sixteen endurance-trained male cyclists (age 26 ± 6 years, body mass 72.2 ± 6.8 kg, height 179 ± 5 cm, VO2 max 59 ± 7 ml.kg.min-1) participated in this randomised double-blind, placebo-controlled, crossover study. All participants consumed 120mg.kg.body mass-1 of calcium lactate or placebo 70 minutes prior to performing an exercise performance test comprising of five repeated blocks consisting of a 1km and 4km time trial interspersed with 10 minutes of moderate intensity exercise. Blood samples to establish acid base measurements (including pH, HCO3-, lactate, glucose) were collected pre-supplement, pre-exercise and pre and post each time trial. In addition, heart rate, perceived exertion and gastro-intestinal tolerance were assessed. RESULTS: There was no significant effect of lactate supplementation on exercise performance (p=>0.05), despite significant reductions in RPE (block 2; p=0.00; block 5; p=0.04) and increases in strong ion difference and bicarbonate levels during the first few blocks of exercise (SID: block 1, p=0.02; block 3, p=0.02; Bicarbonate: block 1, p=0.03; block 2, p=0.03, block 3, p=0.04). Calcium was significantly higher (all blocks, p=<0.05), whereas chloride was significantly lower (all blocks, p=<0.05) following lactate supplementation. Potassium levels were significantly lower during the final 3 blocks of exercise (block 3, p=0.01; block 4, p=0.01, block 5, p=0.02). CONCLUSION: Lactate supplementation did not improve exercise performance, despite positive changes in acid base balance and RPE indicating the dosing strategy utilised was insufficient to elicit sufficient alkalising and metabolic influence.