JEFF: I donate blood every 56 days and would like to know if it affects your running? I only run 3 miles three times a week and for some reason I just have no energy for about a week after I donated blood ... is it in my head or can it affect me that long?
I'm female, about 5.8 and weighs 147lbs ... if that will help.
ANN: A standard blood donation will not usually be felt in everyday life. Running requires much more oxygen and the blood donation has removed just enough oxygen carriers (red blood cells) to make a difference. According to medical experts, your body replaces the red cells within about 2 weeks.
What you are feeling is normal. I suggest going slower and taking more walk breaks during that replacement period. I would not donate blood if you are running a long run or a long race within the two week period after giving blood.