It depends how severe things are. With low platelets, anything involving too much contact should be avoided. With low haemoglobin, exercise can become physically impossible but it's important to try to keep some muscle strength. When I was bedbound with low platelets and low haemoglobin, I did gentle strengthening exercises in bed, supervised by my physiotherapist. I've still had to relearn the whole walking thing and am working on increasing my strength under physiotherapist supervision. Every week I can do a bit more. I've developed issues with ligaments and tendons from returning to activity but I'm being careful so things are pretty mild. It's important to avoid the boom/bust cycle with activities.