hello i am a mountin bike racer, race all over the world and compete at top of my game (for my age 50 no spring checken) for the last 2 to 3 years the amount i train has not equaled my performace and i have just found out i have COPD, i race enduro and downhill what is a lot of stress on lungs and heart, how dangous for me is it to still push my self knowing the stresses, is there anyone else out there in the same situation, i am not ready to give it all up and am a bit lost