I can run a safe session for a healthy client no problem. But then someone shows up with a bad back, or a knee that's been replaced, or a heart condition, and I get nervous about every exercise I give them. I don't want to be the trainer who made something worse.
More people experience this than they realize.
You can train the healthy safely, but real injuries and conditions still worry you.
If this sounds familiar, the Library can help you find the bigger picture.