I know Dice-K and Bengals QB Carson Palmer when there arm gets tired in practice they don’t stop throwing they just throw lighter eventually there arm builds endurance
You need to be careful about going overboard, however. Endurance sessions are useful if you complete them once every 2 or 3 weeks. Also, try to keep a maximum cap to the workout. For a starting pitcher, the highest number of pitches they are normally allowed to throw would be 130-140. So try to avoid going much higher than that.