I had altitude issues a couple of times when I went to the Rockies, and they just about did me in.

Coincidentally I discovered I was pretty severely anemic a little over a year ago.

I think we know why I had difficulties prior to that, right?

Last year, after being treated for the anemia, I returned to the Rockies. Didn't have the probs I had before, but wasn't 100%.

But this year we went and I had no probs.

My guess is that your body just wasn't quite ready to handle the altitudes and exertion because of your previous anemia. Try again next year and I bet you'll rock it.