Figure 2.

Training protocol. Anodal transcranial direct current stimulation (tDCS) (2 mA, 10 min) is applied to the primary motor cortex for the lower extremity during muscle strength training. In the sham tDCS experiment, the same procedure is used, but it is only delivered for ~15 s to mimic the transient skin sensation. Muscle strength training consists of 3 sets of 10 maximum isokinetic eccentric contractions on the knee extensors and flexors, with a 150-s rest period between sets. Training is performed once every 3 days for 3 weeks (7 sessions).