<qa>  How many sessions will be performed once a week?A crossover trial with healthy volunteers will be conducted. Six sessions will be performed once a week in a counterbalanced order and at least with seven days washout period to minimize carry-over effects. In each session, volunteers will be submitted to quantity and quality of sleep, type of eating, fatigue and motivation level, cortical brain activity measures through paired pulse transcranial magnetic stimulation ppTMS, spinal cord activity measures through electrical stimulation, non-invasive spinal stimulation tsDCS or non-invasive brain stimulation rTMS and physical exercise gait training. 