Zone 2, nasal breathing, and freediving are all having a moment right now. Here is how they connect. I started running a year ago, after twelve years of CrossFit, where a 400-meter run counts as endurance work. As my runs got longer, everyone told me I needed to get into zone 2. I argued up and down that my body simply was not capable of it.
What freediving taught me about CO2
Last summer I was preparing for a freediving trip and could not get enough time in the ocean to train my breath holds. That meant dry apnea training, in other words, practicing breath holds on land.
In freediving, we know that the reason we have the urge to breathe is our CO2 tolerance. According to oxygenadvantage.com:
Nasal breathing during running slows your breathing and reduces breathing volume. It causes blood CO2 to increase, which means more oxygen gets to your muscles. But it also means stronger air hunger, and that can feel unpleasant.
I may not understand all the science behind this, but I have practiced it a lot. When I cannot get into the water to train my breath hold, I jump on my stationary bike and do breath hold ladders while pedaling. The pedaling simulates the kick strokes of freediving. One thing I noticed right away: the longer I held my breath, the faster my legs wanted to pedal.
It got me to zone 2
What I can say unequivocally is that it did not take long. Once I started using nasal breathing on my runs, I finally got to a zone 2 pace. It is near impossible on speed work, but for easy running it did what months of arguing about heart rate never did.
Getting started with nasal breathing
- Try it on a short easy run, or just during your warm-up, and slowly increase the time.
- If the urge to breathe through your mouth gets strong, take the breath. Do not fight it.
- A longer exhale will lower your heart rate. The inhale raises it.
- Slower music. I love running to classical. It slows down the noise in my head, which slows my breathing, which lowers my heart rate, which makes my feet feel lighter, and I actually run faster.
One rule that is not optional
Any type of breath hold should never be done alone. It is extremely dangerous and you need a safety partner. This applies on the bike and on the couch, not just in the water. Nasal breathing on a run is a different thing and is safe to practice solo, but breath holds are not. If you have any respiratory or cardiac history, check with your doctor before adding breath work of any kind.
Where to learn more
For more information, I find the HHP Foundation, Brian MacKenzie at Shift Adapt, and Patrick McKeown are all great resources.
If you want to try this with company, we run together most weekends. Come find us on the training page, or if you are thinking about the marathon itself, start at join the team.
