Influence of Fast and Slow Imagined Muscle Contractions on Muscle Function or Central Nervous System Properties

The goal of this randomized clinical trial is to learn if imagining fast or slow muscle contractions causes different responses for nervous system excitability and muscle function in young, healthy males and females in. The main questions are: Does imagining fast muscle contractions cause greater nervous system excitability compared to imagining slow muscle contractions? Does imagining fast muscle contractions increase muscle function compared to imagining slow muscle contractions? A control condition (rest) will be compared with two intervention conditions: imagining fast and imagining slow conditions, to determine if the fast and slow increase outcomes more than control and if fast has the greatest response. Participants will: * Attend 4 laboratory visits * Perform 50 imagined contractions fast or slow, but with no physical movement * Physical muscle contractions and non-invasive brain stimulation would be completed before and after each condition.