Zone 2 Training–what it is and why you should care

I have good news for anyone who wants to start their fitness journey. And, bonus, the good news also applies to people who’ve already made exercise a part of their journey. The good news is that we should all be doing more Zone 2 training. 

Zone 2 has become a massive buzzword in the fitness world over the last few years, especially after Peter Atilla’s book Outlive came out last year. I wrote about it here, but the book is a handy guide to all the lifestyle and medical interventions that one can incorporate into their routines to give one the best chance at living a long and healthy life.

Atilla also has a podcast called The Drive, where he dives deep into many of the book’s topics, including several on Zone 2 training.

So, let me get to the point and tell you what Zone 2 is and why you should do some of it.

The technical definition of Zone 2 training is the rate of exertion that keeps lactate between 1.7 and 1.9 mmol. But that’s hard to measure without a lab, so today, we’ll use the “talk test” to help you know if you’re in the correct zone. 

To do the talk test, you just have to work (walking, running, or biking are excellent choices for testing) at a rate where you can still have a normal conversation but might sound slightly out of breath. Easy.

But why would you want to spend 80% of your cardio time (the recommended amount) going so low and slow? Because Zone 2 is the best way to enhance the function of something you haven’t thought of since 9th-grade biology: mitochondria (the power plant of the cell, remember?).

Mitochondrial health is one key to living a long, healthy life, and if that’s not good enough, it’s also the key to being an efficient fat burner. Those with the best mitochondrial health will burn more fat at rest and during exercise than those with less efficient mitochondria. And the more Zone 2 training you do, the more efficient your mitochondria will be.

Ironically, this means that well-trained athletes will be in fat-burning mode most of the time, while people with much more fat to lose will have a much harder time accessing those stores for fuel. 

To add insult to injury, the more glucose you burn (the alternative fuel to fat), the higher your lactate levels will rise, which leads to the burning in the muscles associated with a hard workout.

If you’re wondering why I kept saying this is all good news, here’s the good news: If you’ve been putting off exercising because you have a “go hard or go home” attitude, you can shift your thinking to “go easy to get better” instead.

When I got the Peloton bike, I kept doing shorter, intense rides that beat me up. At first, it was fun because I kept seeing improvements from ride to ride.

Eventually, I hit a plateau, and the only way to beat my previous day’s metrics was to go all out. And going all out every day is a recipe for injury. Getting my mind right about getting on the bike was also challenging.

But then I learned about Zone 2, and today, I ride longer and more frequently than ever but at a much lower intensity. I wrote more about my Peloton Zone 2 experiment, and you can read about that here. But this is already getting too long, so I’ll stop for now (although I just reread the title of that article and chuckled, so you should, too).

Go here if you want to get more into the details than I did. There’s even a video interview between Attila and one of the world’s master cycling coaches, and they talk about Zone 2 throughout the conversation.