A, RER. *Sex difference, P < 0.05; †different from exercise, P < 0.001. B, whole-body fat oxidation. *Sex difference, P < 0.05; †different from exercise in both sexes, P < 0.001; ‡different from 10 min in men, P < 0.05. C, relationship between capillary density and fibre type composition in the vastus lateralis muscle and whole-body fat oxidation during exercise analysed by multiple linear regression. LBM, lean body mass.