approached significanceP =0.050
We found that V̇ O 2 ,max did not differ between testing altitudes ( F 1,13 =2.243, P =0.158), nor did the average speed at which highland mice reached V̇ O 2 ,max ( P >0.05) or 75% V̇ O 2 ,max , although it approached significance ( P =0.050; Table 1 ).