Fig 1. Serum CK level in DM1, mdx and WT mice.

(A) CK levels were measured in mouse serum before (blue) and after (red) exercise. CK level was significantly higher in mdx mice than in WT and DM1 model mice, both before and after the exercise regimen (P<0.001). Exercise resulted in a significant increase in CK level in mdx mice (P<0.05), but not in other mice. (B) Exercise in the treadmill resulted in a forty-fold increase in CK level in mdx mice, whereas only a two-fold increase was observed in WT, DM500 and HSA^LR mice and a six-fold increase in DMSXL mice (n = 3–5 per genotype).