Oxygen consumption (V̇O2) (A), CO2 production (V̇CO2) (B), and respiratory quotient (RQ = V̇CO2/V̇O2) (C) in HA (□; running speed, 9.8 ± 0.6 m/min) and SL control (•; running speed, 16.3 ± 0.3 m/min) rats during exercise at 60% V̇O2max. n = 13 for SL rats; n = 7 for HA rats, except where indicated.