I’ve continued practicing the exercises from The Oxygen Advantage for the past several days, and this morning I hit a nice exercise-related milestone.

I decided to take the past two days off from running. Instead I went for walks and practiced reducing my breathing while also doing some breath holds. I figured that some extra practice on the breathing side could be helpful.

This morning I went back to running, figuring I’d continue the interval approach. I decided that if I was going to do intervals anyway, I might as well see what it’s like to skip the 15-minute walking warmup. I wanted to know if that part was even making much difference. So I just walked for two minutes and then started running. That’s what I used to do before I’d read The Oxygen Advantage.

I ran a familiar route where the first half is mostly downhill, and the second half is uphill. I figured that I could probably handle a hill better if it was later in the run, so I’d be more warmed up. I’d previously figured out that nose breathing while running gets easier after about 30 minutes.

The first minute was the most difficult, like I wasn’t getting quite enough air. I felt that I might make it about 2-3 minutes before having to step it down to walking for a couple of minutes. Then I could build up to longer intervals like I did last week. But I kept going even though it felt uncomfortable to breathe this way, and my breathing soon stabilized. After 3-4 minutes, I felt like I could keep going and felt optimistic that I could do an hour of nose breathing running without having to step down to walking.

That turned out to be true. I ran for 70 minutes with nose breathing continuously – my first time ever doing a full run that way.

I ran about 10-15% slower than I used to do with mouth breathing, but I’m happy that I was able to do it. I figure I can build back up my speed as my body adapts better to nose breathing.

I didn’t think I’d be able to reach this point so quickly, so that was a nice surprise. I do think that doing more breathing practice for the past two days likely helped.

In the second half of the run, I also did about a dozen breath holds, usually for 12-13 paces. These are harder when going uphill, so sometimes I only made it 10 paces. Note that breath holds are done after exhaling, so the lungs are mostly empty.

I felt like my breathing wasn’t quite where I wanted it to be for much of the run. It seemed a bit heavier than before, even though I was still breathing through my nose the whole time. Interestingly I found that my breathing got lighter at around 55 minutes, during the uphill portion. The last 15 minutes of the run actually felt pretty nice, like I was getting a taste of what it could feel like to nose breathe while running and have it feel comfortable and natural.

I’d love it if my entire runs could eventually feel like those last 15 minutes – with relaxed breathing through my nose.

It’s an interesting challenge to coax my body into a different behavioral pattern, knowing that it’s going to feel uncomfortable for a while. My body breathes heavier as if it needs more oxygen, but it actually doesn’t. It just needs to build up more tolerance for carbon dioxide.

A key point that The Oxygen Advantage makes is that you know you’re making progress when you feel the desire to take a bigger breath. It’s the discomfort of holding back on that bigger breath that helps you progress.

It’s uncomfortable to breathe more shallowly when my body signals that it wants more air. It’s hard to sip air when my body would rather gulp it.

Running while nose breathing doesn’t feel nearly as comfortable as it felt with mouth breathing. I wonder how long it will take for running with nose breathing to feel normal and natural throughout – or even better than my old mouth breathing approach.

Making progress with personal growth often entails discomfort. Building a tolerance for discomfort in general is helpful. The more we build up this tolerance, the easier it is to step into the growth space. If you’re only willing to grow comfortably, you’ll leave a lot of growth possibilities unexplored.