I can't speak to overtraining, but I had moderate anemia for about six months prior to my hysterectomy last summer, and yes, it can definitely put a dent in your activity threshold. I would be absolutely exhausted after skating for an hour, and the few times I tried to do 90 minutes I started to find it hard to catch my breath and nearly fainted by the end. Near-fainting was probably the most recognizable symptom, actually. I've always tended to get lightheaded when I stand up too quickly, but it got much worse during that time. There was a lot of sitting down as soon as I got up, having to hold on to a wall because my vision was going black, etc. The most unique symptom, though, was a whooshing/pounding in my ears. It was like holding a seashell up to my ear, except it was constant when there was no other noise to distract me. It went away after my surgery and a subsequent blood transfusion.
I also got
incredibly altitude-sick when I foolishly took a vacation to Denver during that period. It was bad enough when we were just hiking, but then we went skiing at something like 11,000 feet, and...I didn't actually get to ski. I collapsed, wheezing, at the top of the mountain and had to be brought down via ski patrol sled. (
Gory details here, about 10 paragraphs in.) I've had a bout of altitude sickness before, so I don't think I can blame it all on the anemia, but I'm pretty sure it wouldn't have been that bad without it.
The last unique symptom was these painful little cracks in the corners of my mouth that appeared to be fungal infections. I've read this is common in people with anemia, though it can happen to anyone.
Anemia is very common in women, even those whose reproductive systems aren't trying to kill them. Definitely get tested. In addition to red meat, green leafy vegetables, some beans, and some grains are high in iron (
one list). If you wind up taking an iron supplement, I found carbonyl iron much easier to take than the more common ferrous sulfate form, as it was much gentler on my digestive system. I've also read it's more readily absorbed than the ferrous form.