Muscle metabolism during exercise and heat stress in trained men: Effect of acclimation

Abstract

Exercise metabolism was examined in 13 endurance athletes who exercised on three occasions for 40 min at 70% of maximal O2 uptake in an environmental chamber at either 20°C and 20% relative humidity (RTT) or 40°C and 20% relative humidity before (PRE ACC) or after (POST ACC) 7 days of acclimation. Exercise in the heat resulted in a lower (P < 0.05) mean O2 uptake (0.13 l/min) and higher (P < 0.01) heart rate and respiratory exchange ratio. Acclimation resulted in a lower (P < 0.01) mean heart rate and respiratory exchange ratio. Postexercise rectal temperature, muscle temperature, muscle and blood lactate, and blood glucose were higher (P < 0.01) in the PRE ACC than in the RTT trial, but all..