Differences in lactate metabolism between middle- and long-distance runners

It is important for runners and coaches to figure out the characteristics of lactate metabolism in terms of planning the proper training. This study investigated the differences in lactate production and oxidation capacities between middle- and long-distance runners by using blood lactate concentration. We hypothesized that long-distance runners have greater capacity to oxidize lactate and middle-distance runners have greater capacity to produce lactate. In this study, 14 middle- and 14 long-distance male runners performed a multi-stage incremental test until exhaustion. Each running stage was 3-minute with 1-minute rest between stages. Blood lactate concentration was measured at rest and after each stage, and some metrics associated with runner’s capacity to oxidative lactate during moderate intensity exercise were calculated. The changes in blood lactate concentration measured after the final state of the test were modeled as a biexponential time function to evaluate lactate productive and oxidative capacities after high-intensity exercise. During moderate-intensity exercise, long-distance runners showed significant decrease in blood lactate concentrations during the first few stages of the test compared to rest, indicating greater oxidation of lactate than production of lactate during moderate intensity exercise (p<0.05), while middle distance runners showed slight increase in blood lactate concentrations even for the first several stages. Middle-distance runners showed significantly higher amount of lactate produced (p<0.05) and greater lactate oxidation during high-intensity exercise than those in long-distance runners (p<0.01), suggesting that both lactate production and oxidation of middle-distance runners were greater than those of long-distance runners during high-intensity exercise. These results suggest that characteristics of lactate metabolism in middle- and long-distance runners depend partly on exercise intensity. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.