An interesting topic appeared in a nearby climbing thread and I figured it could be worth it's own thread. Do you feel any pain and where do you feel it? I've never felt any and have been wondering what others meant. I always thought it was some kind of symbolic pain they talked about. Then lately I've read that well trained pro bicyclists don't feel any pain but amateurs do. Well I'm not a pro and I'm 52 and still don't feel any pain. I'm in fairly good shape now but a year ago I wasn't and there was no pain then either. My muscles just get heavy and I have to use more and more willpower to keep going. If I continue I will go into a deep oxygen debt until I reach a point where I cannot breathe anymore. It's not that I can't inhale. It's more like I can't exhale so there is no sense in inhaling since my lungs are full of waste instead of empty. Sometimes I can feel pain in my windpipes at this point. If I've gone too far into oxygen debt I can barely move forward until I've caught up with my breathing again. It is definitely like slamming into a wall, especially since there is no real warning except my laboured breathing. How do you experience lactic acid? -- Perre You have to be smarter than a robot to reply.