Rage On Two: Zone 2

Part 2 of the Rage On Series. Part 1 is HERE.

You may have heard about “Zone 2” in the gym. Or you may have heard about it from me. A lot of new research is coming in on the benefits of Zone 2 exercise to us humans.

What is Zone 2?

Zone 2 is defined as 60-70% of your heart rate max or 60-75% of your VO2 max.
There are a few ways to find your zone 2 HR range. One formula for zone 2 is 220 – age= Max HR, x 60-70%. Example 220-47= 173 x .60= 103 would be the start of zone 2, 173 x .7= 121 would be the top of zone 2.

The vast majority of CrossFit gym members are really bad at Zone 2 training. And Zone 2 is usually a major gap in their fitness. As in, they have no Zone 2 capacity. Zero. These people skip right over zone 2 and go into zone 3, also known as the garbage zone. More on that some other time.

Why Zone 2?

In the old days, Zone 2 was preached as the fat-burning zone. This may be why you have recently heard about it in the gym. It does burn fat, as does every Zone. The reason it works better than other zones is simple. The person can maintain it for long periods of time, and it burns more fat than normal human activity. A good Zone 2 workout will have you sweating, but the work should feel like you can do it for a very long time. Is it better than Zone 3, 4, and 5? It is for a few reasons, but primarily because you can maintain it longer.

The keynote here. 5 mins of exercise in zone 5 will burn more calories than 5 mins in zone 2. Zone 2 work needs to be long to have an effect.

So Zone 2 is good for fat burning. But it has also been shown to be even better at prolonging health span for everyone and lifespan for many.

Research shows that 180 mins of zone 2 work a week increases health span and lifespan.

The usual dose for this is 4 45 min sessions a week. 45 minutes appear to be the minimum effective time for this benefit.

Would 2 90 min sessions work just as well? I am guessing yes. Would 6 30 min sessions work? Probably. how about 8 22.5 min sessions… We don’t know for sure, but the leader in this research says no to anything below 45 min sessions.

Of course, it should be said as always that if you are starting from zero exercises, any exercise is going to increase your lifespan. There is a magic pill. It is exercise, and you need to take it 4-5x a week for your entire life. 30 mins 3 times a week has been shown not to increase healthspan. It will increase lifespan in those that are currently not exercising.

Zone 2 is good for fat loss and increasing lifespan and healthspan, anything else?


Yes, it makes you feel good. 45 mins of zone 2 work is known to leave you feeling really good. Is it the endorphins? Is it the good sweat without the intensity? I am not sure, but I know if I am feeling shitty, 45 mins of zone 2 will put me right.

Interested in Zone 2 work? Join the Grenell 5×5 Challenge starting December 26th.

Any questions about this stuff? Let me know!

Notes:
There are many ways to get Zone 2 work done in the gym. In research, a bike is almost always used. Bikes are used because they are very easy to control with a sustained constant effort. I have experimented with Zone 2 in Running, Kettlebells, and in CrossFit classes. All can be done, but the bike is the easiest.

Lifespan is the number of years you live. (The USA Medical system is pretty good at increasing this number)

Healthspan is the number of years you are healthy(The USA medical system is not good at increasing this number, that’s ok however because it is easy and cheap to do it on our own.)

An alternative method of finding zone 2:

MAF method: 180 – age= max zone 2 HR
+5 if you have been training for 2 or more years

-10 if you are recovering from injury

-5 if returning from injury of time off

-5 if your waist measurement is more than half of your height.
So for me 180- 47 +5 = 138 bpm. So above 138, I would bump into zone 3

Zone 2 work should be easy to hold a conversation. If you can’t hold a conversation you are not in zone 2. The conversation should be harder than one you would have going on a walk.

Increase your lifespan, and increase your Healthspan. Longevity is simple when you attend a gym that has longevity on its mind. Longevity is always on my mind. Just show up and RAGE ON.
See you in the gym.

Joshua J Grenell