There's a blood drive in my town on the 13th and 14th. I'd really like to give blood but with fasting and everything, I'm thinking I might not be up for it. So of course, one option is to not participate. Another option is to go as early as possible since that's when I'd be feeling best. And the last option is to be the very last to get blood drawn since they close at 8pm and fasting is until just a couple minutes before that. I'd be able to have a bite to eat just before and then have a real meal after the blood-giving. I'd just worry that I will feel really unwell after giving blood when I'm already not very nourished. And if I give at the beginning of the day, I worry that it will cause me to feel so weak I won't be able to complete my fast.