It's not necessarily a good thing to get obsessed with numbers. I used to lift weights back before I became ill, and I was all about the numbers then too. I knew exactly how much I could lift and I wasn't a bodybuilder or anything but I did feel a bit competitive with myself about it, if that makes sense. Now, I know my body has changed forever due to illness. I know I can't do what I did before, that healthy person is gone forever. Now I have to be content with just being able to get through a workout, regardless of how slow/fast I am or how much/little I can lift, etc. For me it's hardest going to the big gym I joined, I have to try really hard not to look at what other people are doing or how much they are lifting, etc. I have to remind myself all the time that my situation is unique to me and that my insides are different from most people's, so I just need to do what I can do and not compete with myself or anyone else. So, don't beat yourself up if you're slower now compared to what "healthy you" in the past would have done because you're a totally different person now. Try to be happy that you can run at all and try not to worry too much about the numbers. I know, I know, totally easier said than done. Being ill really makes you reprogram yourself inside and out, doesn't it!