To give or not to give: that is the question

Miles: 2.25
Pace: ??
Strength training: Arms and abs

It was a beautiful, low-humidity day, so after dinner I went for a light jog without the stopwatch. No scary animal encounter this time, luckily. When I got back home, I figured that it would be good to do some strength training, so I did a few ab exercises and push ups, as well as bicep, tricep, and shoulder/back exercises with some light weights.

Tomorrow is my rest day, and I'd like to do some speedwork on Saturday. I was going to give blood with my support staff on Sunday, but I just googled "run after giving blood", and it looks as if it will have a major impact on my running, especially if I want to increase my distances. If I give blood on Sunday, I won't be able to replenish the red blood cells in time for August 6th, when I want to try to break my 5K PR. In fact, I'd probably just recover in time for the 10K in September, but I wouldn't be able to train properly ahead of time for it. Now I'm feeling guilty, because I don't want to sacrifice my aerobic capacity, but what if a pint of blood from me could save a life? I guess I'll use my rest day tomorrow to think about it.