Essentially what the title says. I will be donating blood tomorrow and I'm not sure how much time should I wait until I can go to the gym again.

Can anyone give me any tips? Don't want to pass out in the running machine but also don't spend too much time in hiatus and I have never actually had this situation before.

I'm a 30 year old male if that helps.

As a younger man I donated regularly.

After donation I immediately resumed normal activity including sport !

You may need to have a few days rest !

Performance will be reduced for a day or two, but there's nothing to stop you exercising immediately after, apart from the risk of bleeding where they stuck the needle in. (The American Red Cross advises waiting 5 hours because of this risk, but they're being over cautious.)

No reason to wait more than a few hours if you feel OK.

Thanks everyone! Already donated and feeling mostly fine (better than expected). I'll wait for tomorrow just to be safe.

The first thing i do after donating blood is try to get sugar into my system. I usually grab a big meal and rest for a few hours before i work out. Actually wait for a day or two before working out just to be on the safe side.