Sample size justification
Using Experiment 1, cerebellar excitability changes after the fatigability task 2, with a medium to large effect size (0.56), a significance of < 0.05, with a power goal of at least 0.80, we required 10 participants to power Experiment 2. However, because of the low tolerability of CBI we recruited a cohort of 20 participants, of which 12 tolerated CBI.