[bonjing]

No help from me. But if it starts to hurt I just back off and build back up to where I doesn’t hurt anymore. Although the shoulders are a “small” muscle, they are capable of a lot. They were meant for lifting, carrying, dragging things... if you can do 50 without any pain other than muscle soreness I think you’re good. But even hips take a beating when running or any tip of impact and one wrong movement can screw you up good. Just listen to your body.