how long after blood donation ...

I relaxed for a week after my first tri and I've been itching to get back to the pool this week but life keeps getting in the way. The planets, and various mundane schedules, have aligned to make early tomorrow morning a good time to swim. I was resigned to missing that oppertunity too, since I had an appointment to donate blood after work today. However, the warnings they gave at the clinic only cautioned me to avoid heavy lifting for 6 to 8 hours.

I realized afterwards that I may still be ok to go swimming as that would be at least 12 hours later. Sure, I'll tire a bit quicker but I could get out for some easy laps. The only thing I'm not sure about is if soaking the needle site in the pool that soon would make it likely to re-open. Is 12 hours after a donation long enough to wait before swimming?