hi, I have an injury that is currently making it very difficult to run. I want to take some time off and pool run, but I've never done this before. I really want the pool running to keep my endurance up, but I'm not quite sure how to do it(the few times I've tried pool running, my heart rate didnt go up that much). Could someone let me know about propor form/how long I should pool run for if I wana stay in rly good shape? Thank you so much