(B) Exercise studies. Male 6–8-mo-old PGC-1α−/− and PGC-1α+/+ mice were subjected to a run-to-exhaustion protocol on a motorized treadmill (left graph) as described in Materials and Methods. * p < 0.001 compared to corresponding PGC-1α+/+ values. VO2max measurements were determined for 2-mo-old male mice for each genotype using a motorized treadmill at an elevation of 150 m and indirect calorimetry set-up (right graph) as described in Materials and Methods. * p < 0.05 compared to corresponding PGC-1α+/+ values.