Hi All, this is my first half marathon and I'm struggling a little bit. I have one month until my first half marathon. I did something I shouldn't have done last week and that was donate blood....since then I have been struggling. I ran 9 miles the Saturday before I donated blood.....now I am struggling with 7. Will this get better soon?
Yes, you just gave up a good-size percentage of your oxygen carrying capacity. You should be OK for your half. Here's the info. It does vary person-to-person. You will probably feel sluggish for a few days to a week after donating. It will take about 24 hours to replace the fluid but the hemoglobin/red cells take a few weeks (typically 4 weeks for red cells, 8 weeks for the iron). And those are the O2 carriers. Proper diet helps but it still takes time. I have run a pretty good race (up to 10 miles) about 2 weeks after donating. So you should be OK for the half. I'm usually good for all but the very longest runs (i.e. 20 milers) within a couple weeks.