Hi there - I have one lung (my left one was removed 3 years ago as a result of metastatic bowel cancer). I am a really keen runner and always was prior to being diagnosed back in 2013. I have run a few marathons and try to do my best now to hit the treadmill most days. Since my lung was removed naturally this has effected me very hard and I am nowhere near as quick as I used to be and cannot sustain the distances I used to. I wondered whether anyone had heard of people like me using pure oxygen on a treadmill while running to help with this. It is a good idea and if so where can you purchase it. Thank you very much Tom