Zone Fun Training
There’s lots of talk about Zone 1, 2, 3, and 4 cardio, with each “zone” based on the level of aerobic or anaerobic energy you’re utilizing. The lower the zone, the more aerobic you are and the more fat you’re burning as percentage of total energy. The higher the zone, the more anaerobic you are the more glucose and glycogen you’re burning. Lower zones are easier and slower. Higher zones are harder and faster.
This is a sound way to think about “cardio,” but it doesn’t cover every zone. There’s one big training zone missing from the conversation: Zone Fun.
In Zone Fun, intensity doesn’t matter. It can be high or low. You can go fast or slow. Intense or easy. Zone Fun oscillates across all the heart rate zones. Because the prime concern and determinant is whether or not you’re having fun, the other stuff melts away. Not in importance—all the aerobic zones still matter, intensity still matters—but in what you have to consciously pay attention to.
You can just keep going as long as you’re having fun and moving your body.
I’d go so far as to say that hitting Zone Fun is the most important metric for your cardiovascular training. If you reach Zone Fun, if you’re moving fast and slow and medium and moving with intensity and then slowing things down, you are doing the right thing. You are improving your health and fitness. Having fun is a good barometer for doing the right thing health wise. Your body intrinsically “knows” when you’re improving skills, increasing VO2max, building an aerobic base and your ability to tolerate anaerobic discomfort, strengthening muscle—fun is the tell.
We have evidence that Zone Fun training is even more effective than other kinds. When you subject rodents in the lab to forced exercise—sticking them on a rodent wheel, making them tread water, tying weights to their tails and making them drag them and climb ladders—you see moderately beneficial effects, but sometimes negative effects. When you give rodents the opportunity to engage in voluntary exercise like free access to a wheel, and they choose to do it, the benefits are greater. For instance, one study found that mice doing a ten week voluntary running program had more favorable shifts in muscle tissue fiber development than mice doing ten weeks of forced running.1 Another even found that mice with colitis had higher mortality and inflammation when they were forced to exercise and lower inflammation and mortality when they chose to exercise.2
Okay, so what are some ways to practice Zone Fun training?
Ultimate Frisbee
My favorite way to get into Zone Fun is with the greatest sport of all time: Ultimate Frisbee. Sadly, I don’t get to do this as often as I’d like to. But when I lived in Malibu, I had a weekly game set aside with the same group of guys. It was a mix of running, jumping, throwing, jostling for positioning, sprinting, and jogging. Most importantly, it was fun. It was a game. It was a game requiring strategy, planning, and intense concentration. Because when you’re concentrating or when you’re thinking ahead and thinking in the moment, you’re having fun. You’re not thinking about the hard work that you’re doing. You don’t even realize that you’re breathing hard, that you’re starting to get sore. You don’t notice the burning. And therein lies the beauty of Zone Fun.
Fat tire biking
I’ve taken fitness influencers out on the sand that are half my age and they always tell me it’s the hardest workout of their lives and can barely keep up. No joke. But the thing is, you keep going because riding through sand next to the beautiful water, seeing all the lovely sights that one sees, invigorates and makes the work worth it.
Standup paddling
Paddling is my other method of Zone Fun training. Up on the paddleboard, I get into my rhythm and flow, and the hours just melt away. I'm never quite breathing hard. My serratus anterior muscles are getting an incredible workout (there's no better ab exercise). My heart is working, the blood is flowing, and the fat is burning. This is a gentle form of training.
Play sports
The perfect way to access Zone Fun training is to play sports.
Pick a sport that you used to really enjoy when you were younger. The trick to training is that it shouldn’t feel like work. You also shouldn’t feel like you’re learning to play. You should come into it fairly naturally. So, if you’re playing basketball, you should be able to dribble the ball, make a layup, and generally feel comfortable with the flow of the game. If you’re trying to pick up a game of soccer, make sure that you’re comfortable handling the ball, passing, shooting, and generally move with the way the game moves. And that’s true for anything. You don’t want to be learning the fundamentals when you’re trying to engage in Zone Fun. You don’t have to be an all-star, but you shouldn’t be a total beginner.
Make the boring interesting
Another way to use Zone Fun training is to take what might normally be a boring form of movement and make it more interesting and fun. For example, instead of running on a treadmill, go for a trail run. Changing topography, textural shifts, rising and climbing the trail, plus all the plants and animals and beautiful smells around you, will make what’s normally a boring plod around the track much more interesting and fun. Deep into the endurance world, I did most of my training on trails and mountain passes just because it was so much more interesting than just running around the track or on a treadmill. It was the only way I could make the incredibly uncomfortable training bearable.
Another substitution might be mountain biking instead of road biking. Insead of zoning out on a road, you have to constantly stay alert for roots, rocks, jumps, drops, and trees. You have to stay immersed in the moment—you can’t just bear down and suffer like you can on the road. This gives you just as good a workout without feeling like it.
Rock scrambling
Rock scrambling is my absolute favorite way to traverse the wild. I grew up in a small fishing town in Maine, scrambling all over the rocks that lined the coast. I think this was how I got most of my movement and training foundation. There's something so satisfying about scrambling on all fours up extremely steep rock faces. It’s just pure fun and I think it triggers something primordial within us.
Loaded partner carries
Here's what I mean by loaded partner carries:
Get a group of at least two people together. Choose a walking path, ideally with an incline. Up a mountain is best. Then, pick a heavy object, at least one per person. If you have two people, choose 1-2 objects. If you're a group of three, choose 2-3 objects. And then you go on the walk while carrying the objects and switching off with each other.
A kettlebell and a weighted sandbag. A big log and a heavy rock. A pair of dumbbells. A barbell and a rucksack. You get the idea. Just go on the walk with a friend or friends, taking turns carrying the objects you brought. This is very hard work, but because you're working together, it's fun. You have each other to lean on and nobody wants to let the other people down. Turns out that camaraderie is extremely motivating.
Those are my favorite ways to train Zone Fun. What about yours? How will you incorporate more Zone Fun training into your regimen?
References
https://pubmed.ncbi.nlm.nih.gov/33118684/ ↩
https://pubmed.ncbi.nlm.nih.gov/23707215/ ↩
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* This blog reflects my personal views and opinions and isn’t intended as medical advice, but I hope it will be informative and inspiring as you pursue a healthy, fulfilling life.



