My husband and I left Boston at the end of August to start a new life in the Mile High City. I was training in Boston throughout the summer and feeling pretty good about not only the distance I’d been covering but also the speed at which I was going. I had just PR’d in a 10K and was feeling on top of the world — until I actually got to the top of the world, that is.
It’s been a little over a week since we moved to Denver and as I indicated in my latest Instagram hashtag #altitudeyou’rekillingme. I have never felt so humbled. Now I understand how newbies or those getting back into running feel. It’s hard!
To be honest, the first two runs I took in altitude weren’t horrible. I felt strong and although I was a little out of breath it was nothing traumatic. As I finished up my second run, I actually started to believe that all the training I had been doing at sea level was enough and that I might just skip the acclamation process. Ha. This morning I finished out my sixth run and even getting to the 5K distance felt like torture. So I did a little research on running at altitude to figure out what’s actually going on and I thought it might be helpful to share what I found with those of you considering altitude training or races.
To preface, I am not a scientist nor have I ever claimed to be. This is just a simple synopsis of my research, which I tried my best to make easy to digest.
The issue with running at altitude is not that the air has less oxygen, which was news to me as I thought that was the definition of thinner air. In fact, the air contains the exact same percentage of oxygen as it does as sea level (21 percent). The problem is that at altitude there is the lower atmospheric pressure, making the oxygen molecules in the air more spread out, decreasing the amount of oxygen you get with each breath. This affects how saturated your red blood cells get with each inhale, which is important because red blood cells carry oxygen from our lungs into our bloodstream and subsequently into our muscles and tissues.
The good news is that over the course of a few weeks at altitude, your body will compensate for the lack of oxygen by creating additional red blood cells, which in turn, increases the carrying capacity of oxygen to your body. This is the idea behind high altitude training.
If you train at high altitude we’ve established that you create more red blood cells, which comes in handy when you head down to sea level because you still have these extra red blood cells on hand. With higher atmospheric pressure creating air that’s denser with oxygen and the extra red blood cells to carry this oxygen, you create a natural advantage.
So now you know what exactly happens to makes running up high so hard. Up next: how to make altitude running more enjoyable.
Written by Lisa Horvath.