Fatigue for me is like never having enough sleep, even after getting bathroom trips down to one or two a night and eliminating the hot flashes. If I am actively using my mind, I am fine, but five minutes in a doctor's waiting room I can be sawing logs. Half the battle of physical activity is working up enough ambition to get my dead behind out of my chair. Then several minutes of breathlessness and leaden limbs and this 75 year old man can do what I did at 50 albeit somewhat slower