Re: Giving Blood need help???
Bring in a zone or paleo snack don't eat the crap they offer. Where I donate they have trail mix cookies, krispy kreme and pop. I usually have chug two glasses of water and have a couple of coffees before I go. On the comment card ask for mixed nuts and fruit, see if you have better luck than me!
Advise: I usually do my workout in the am before donating, or if I do a workout later do not do a met con it won't be fun... On a rest day it is fine. I am slightly more winded during workouts for a few days after donating, but go in every two months and have for years (good Karma). It is also healthy for men to donate and keep your iron stores in check you want your ferritin level below 100!
If you are giving a double unit of blood they will send in some IV saline to keep you from dropping on the way to the car. Bad for business!
For a normal donation they don't give anything back just tell you to drink lots of fluid and don't do heavy lifting that day.