I have always been active and I exercise at home following Youtube videos but I find hard to adjust these exercises to myself (because I want to go on with the lady on the video) so instead of e. g. doing mounting climbers I do it on my knuckles. But I would like to know if it's safe or not because I know my way isn't right way of doing these exercises. I do manage use my knuckles for 30-60 seconds until I don't feel my fingers (due to stopping blood flow in this position) or my knuckles does hurt. And I would really appreciate any ideas how to adjust these exercises or if I should just skip them.