Welcome, Tigger! Are you talking about taking old pedals off and putting the new ones on in regards to muscle? You should have seen me cursing the wrench, the bike, the pedals as I tried to power the pedal nut one direction and the pedals spun the other direction. I'm sure wiser heads would have said, well why didn't you just lay the bike down on it's side to get better leverage? but I was too lazy to take it off the trainer and too stubborn to ask for help. I'm going to have to take a training course in maintenance and repair!