Blood Donation and Performance

Are you required to donate blood in the UK? Just curious if that is a consequence of your health care system. I would save the donation for after your marathon if possible. Might not harm you as much training for a marathon as for a 5K, but will inhibit training at least slightly for a few weeks.

There are some other threads on this if you use the search feature (trying to be helpful, not trying to be a jerk).

Anecdotally, I gave double red blood cells about a month and a half before a ten miler I was working towards a few years back and never seemed to quite recover. I ran about two to three minutes slower than what I was planning for and what earlier season workouts had seemed to indicate, though I always seem to be more of a mid-d guy and start to fall of after about two miles. I don't know if the blood donation had anything to do with it (wouldn't want to make the old post hoc ergo propter hoc fallacy), but I felt like I was dragging the whole rest of the season after it.

Thanks for your replies guys.

We are not required to donate here, but I have been putting off my donation until the end of the season. In other words, I am trying to balance between being a good citizen and selfish runner!

I donated the same week as a 10k back in July and I was certainly sluggish during that race, and didn't pick up fully until September. I have a 10k in early January so I may just put the donation on hold for a while.

You should be fine by then

A blood donation is about 10% of your blood and hence about 10% of your red blood cells. With that goes 10% of your hemoglobin. Your hemoglobin of course is what transports oxygen and carbon dioxide. Not surprised that you felt sluggish if you donated the same week as a 10k but 6-7 weeks afterward a donation and your red blood cell count should be approaching its normal level. In a marathon your limiting factor shouldn't be the oxygen and carbon dioxide-carrying capacity of your blood anyway so the effect should be minimal (unlike a 10k, where your ability to transport and excrete CO2 matters significantly). Please don't push it for a couple of days after a donation though. After a couple of days plasma volume will have replenished and you can start pushing again.

Go donate and kudos for being a good citizen!

Your blood parameters should be fully back to normal in 6-7 weeks. The problem is that you're taking a hit during the last few peak weeks of training and this absolutely will hurt your performance on race day. If performing your best in January is important you should not donate blood between now and the race. If you feel compelled to donate blood, wait until a down time in your training.

Went for a run after posting and whilst out I was thinking along the same lines as what Citizen Runner has just posted above. It's not just about whether you body will be back to normal by race day, it's about how a donation will affect the next few weeks of training. Hard workouts will be affected and your recovery will be reduced since resources are being spent elsewhere.

The amount of time it will cost in your marathon will only ever be guesswork but I would have a hard time being convinced it's worth more than a couple of minutes maximum. I guess you have to decide what's more important: donating blood or eliminating the potential impact of doing so.

Really interested in hearing opinions of others though, especially those who have donated and raced. I haven't donated for years and I feel a bit selfish for not doing so. It's not like it's making the difference between winning races or not for me.