Table 1. Body weight, heart weight, ratio of heart weight to body weight, and run time after the endurance exercise training.

Variables	Trained (n=6)	Untrained (n=6)
Body weight (g)	25.9±2.2	29.3±1.6*
Heart weight (mg)	140±8	160±29*
Ratio of heart weight (mg) to body weight (g)	5.40±1	5.46±1
Run time (min)	40.1±9.4	33.5±7.3*

Values are means±SE. *Significantly different (p<0.05) from the trained mice