Table 3.

Voluntary wheel running exercise performance of MuRF1^+/+ and MuRF1^−/− mice

	Week 1	Week 2	Week 3	Week 4	Week 5	Overall (Weeks 1–5)
Running time, min/day
MuRF1+/+	329.8 ± 28.8	348.4 ± 18.5	323.0 ± 25.4	359.8 ± 19.3	341.3 ± 16.3	343.1 ± 14.8
MuRF1−/−	349.9 ± 28.8	375.5 ± 24.6	325.1 ± 24.3	384.5 ± 17.0	382.3 ± 31.1	363.7 ± 18.7
Speed, mph
MuRF1+/+	2.80 ± 0.199	3.30 ± 0.161	3.31 ± 0.171	3.59 ± 0.146	3.64 ± 0.169	3.31 ± 0.142
MuRF1−/−	3.46 ± 0.224*	4.84 ± 1.71	4.52 ± 0.303*	4.92 ± 0.256#	4.92 ± 0.407*	4.47 ± 0.279*
Distance, km
MuRF1+/+	10.1 ± 1.2	12.2 ± 0.93	11.2 ± 0.96	13.9 ± 0.87	13.1 ± 0.91	12.1 ± 0.73
MuRF1−/−	13.0 ± 1.7	19.0 ± 2.1*	15.6 ± 1.83*	19.5 ± 1.32*	19.9 ± 2.5*	17.2 ± 1.5*

Data are expressed as means ± SE. MuRF1^+/+, n = 8–9/wk; MuRF1^−/−, n = 8/wk. Rarely, mice stopped running and were excluded from further study (preventing a repeated-measures statistical analysis). Student's t-test was performed to compare MuRF1^−/− with WT control animals.

^*P ≤ 0.05;

^#P < 0.001 MuRF1^+/+ vs. MuRF1^−/−.