About 5 years ago I was also suffering from fatigue during my radiation treatments for prostate cancer, I was also on Lupron Depot shots at the time. I had been riding a trikke for over a year and I saw no reason to stop. I kept at it along with light weight training. As far as I'm concerned exercise has helped me, even now that I have my strength back at times I feel fatigued, I jump on my trikke or hit the Y, afterwards the fatigue is gone. Exercise, the other medication.