A blood plasma donation center is opening up close to where I live soon and I was curious as to what sort of side effects I might experience by donating with regards to my exercise performance and body composition.

Lowered iron and oxygen levels because of lost blood will no doubt effect exercise performance, but in what way and to what extent? Likewise, the body will obviously lose weight in whatever amount of blood was lost, but during the period in which the body tries to restore that lost blood more energy would no doubt be expended right? Assuming that this temporary energy expenditure is significant enough to warrant consideration, what sort of range might be expected and for how long?

2 Answers 2


If you donate blood:

  1. No sport the day you are donating, neither before nor after
  2. You need to replace the lost fluids. Drink a lot before and after donating
  3. For replacing the blood cells you don't need so much energy but iron, keep that in mind especially if you are female or vegetarian
  4. Your stamina will suffer the most, keep endurance exercise on a lower level than usual for the first few days after donating
  5. Fully replacing the blood takes 6 to 10 weeks, don't go too often and give it some time before a competition.

Christian's answer is good for blood donations. While I haven't donated in over a decade, my understanding is that there hasn't been many changes in the taking of plasma.

When one donates plasma, they filter out the plasma and return everything else so you aren't losing any red blood cells. Then in the end, they pump in a bag of saline to help replenish the fluids (at least that's how my center did it a decade ago).

I was of average capacity in terms of running and lifting weights and I don't remember ever feeling any side effects, but I was young. When one donates blood there's usually a sitting period so that the staff can watch out for the donor passing out. With plasma, that is not the case so in theory exercising/competing can be same day.

Also, since donating plasma is different one can donate twice a week as opposed to once every 8 weeks.

  • i totally forgot to talk about plasma. i added to my answer, that it only counts for blood donations
    – Christian
    Commented Jun 27, 2019 at 12:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.