Figure 4: Time-course changes of protein expression. (a) The level of p70S6K phosphorylation at Thr389. (b) The level of ERK 1/2 phosphorylation at Thr202/Thr204. HFS: high-frequency electrical stimulation group. LFS: low-frequency electrical stimulation group. UT: the untrained leg. The relative value was defined as the ratio of trained leg against untrained control leg. All values are the mean ± SD. * , ** , and *** versus UT; versus HFS; , versus Post0.