want to get fit? run slow
We’re working way harder than we have to.
Heart rate training has taken the world by storm with the development of smartwatches and fitness trackers. It’s an accessible way for virtually anyone to better understand their physiology and push their bodies to the limits. While running at a variety of paces and distances is key to being a well-rounded distance athlete, what if there was a scenario in which you had to pick just one zone? Is there a favorite that gives the best return on investment?
The answer is clear as day. It’s zone 2 training.
While I’ve made arguments in the past for why threshold training is the most underrated or neglected zone, it’s still got nothing on the power and sustainability of zone 2. Today I want to break the physiology to explain exactly why this is the zone you should be running in most often and how it can transform every aspect of your training.
Let’s dive in.
the fate of your cardio lies in zone 2
Before we get into any fun physiology (don’t worry I’ll keep it super basic), I feel the need to provide a couple of disclaimers. First of all, don’t feel like you have to train with heart rate. If you prefer to leave the watch at home and run off of feel, I commend you. I’m by no means stating that you need to use this method to improve, it’s just one evidence-based option that can certainly help.
Secondly, just because this zone is most beneficial doesn’t mean you can skip out on the others entirely. If you’re someone who does want to run fast, you need to train fast too…just not quite as often as you think.
Finally, the whole philosophy around zone 2 training is volume and consistency. If you’re brand new to running, I strongly discourage you from diving into huge mileage right away. Take things slow and gradually increase your distances over time by no more than 10% over consecutive weeks. If you’re unsure where your fitness lies and what plan is best for you, talk to a trusted health professional who can get you started on the right foot.
where is my zone 2 anyway?
While this question has been overcomplicated by every application under the sun (Garmin, Strava, Apple Health) giving their own equations for zone estimations, the principle of finding zone 2 is quite simple. It’s the intensity that requires you to work a little, but you could still have a conversation with a running buddy quite comfortably.
From a numbers perspective, this zone typically lies around 65-70% of heart rate max or 70–85% of lactate threshold. While heart rate ranges will vary significantly due to age, fitness status, and more, it’s safe to say that a relatively fit athlete running at least 30 miles per week would hover between 120–145 beats per minute.
Fortunately, due to the wide range of zone 2, you can likely get away with following an app-estimated calculation as long as you’re listening to your body and watching that your perceived effort doesn’t go beyond a 5–6 out of 10.
Again, none of these methods will be 100% accurate, but it doesn’t need to be. Once you begin to train around this range more often, you’ll find that your body naturally picks up what zone 2 feels like as it’s that comfortable steady state you can hold for quite a long time. As long as you stay in your lane and don’t get tempted by picking up the pace, you’ll begin reaping all of the benefits that this great training principle has to offer.
Why do i need to train at this intensity?
I’d argue that you should be doing at least 70–80% of your total weekly volume in zone 2. While this may sound crazy, it starts to make sense when you realize just how much impact it has on your physiology. As I mentioned earlier, it’s the greatest return on investment out of any of the zones. There are 5 distinct reasons why this is the case…
1) Our bodies are naturally designed to operate at this pace.
The main reason why there are so many benefits to zone 2 training is that it’s the most relevant to the body’s natural capacities. From an evolutionary standpoint, we were never meant to push ourselves to the limit aerobically or anaerobically. The body is more designed for long efforts of low to moderate exertion (see this article on the phenomenon of persistent hunt for more).
As I’ve touched on recently, a maximal effort is rarely optimal. This rings true for many areas of fitness but is especially relevant for distance runners. If you want to get the most physiological benefits while keeping your health in equilibrium, you must follow the natural course of the human body’s evolution and development.
We’re not cheetahs…at least not yet.
2) You can utilize the most efficient fuel.
Running at zone 2 allows you to burn fat as fuel. This is by far the most sustainable way to run as our stores are far greater than glycogen. This means you can run significantly longer than if you were dipping into any fuel that’s more physiologically demanding on the body.
This is the state that allows ultra-marathoners to do what they do without collapsing after a few hours. It’s also the secret to getting a great time in a marathon without hitting the wall as you can you can essentially bank your glycogen until you need it near the back half of the race.
3) It’s the best method for increasing aerobic capacity.
Aerobic capacity can be broken down into three main components: oxygen uptake (activity in the lungs), oxygen transport (bloodstream), and oxygen utilization (cellular respiration). Fortunately, zone 2 training boosts all three elements due to the ability to increase red blood cell count, enhance oxygen affinity, develop a more efficient and powerful heart, stimulate mitochondrial biogenesis, and more.
If we’re using influencer terms, this is the key to “bio-hacking” as you improve virtually every physiological metric that matters for aerobic-based athletes. Pretty cool, right?
4) It’s safe and sustainable.
By far the most underrated aspect of zone 2 training is the low injury risk and sustainability. Due to running at a low intensity, your musculoskeletal system is put under much less duress, allowing you to both recover faster and run higher mileage without injury. This means more time working on your engine and less time resting and waiting. Just remember…
Volume + Consistency = Aerobic Gains
5) It’s accessible to everyone.
My final point is directed at all of you novice runners or those on the fence. I hope this post encourages you to remember that running doesn’t have to be an all-out effort to be incredibly rewarding and effective. Even by running at a 5–10 intensity, you can rewire the very make-up of your cardiovascular system and improve your fitness for both performance gains and overall health maintenance.
Running shouldn’t always be hard. If you can slow down and find that perfect pace, you can start to appreciate just how enjoyable it can be. It’s an adventure. It’s exploration. It’s an expression of yourself. It’s community. It’s for everyone.
If you’re looking to become a better runner, look no further than zone 2 training. It’s the holy grail of running. It’s the most powerful zone to maximize your health and fitness while staying energized and injury-free. The best part? It also happens to be the most accessible part of training. No matter your age, history, or training status, you can thrive with zone 2 training. All you have to do is get out for a run and experience all of these fantastic benefits for yourself!
You got this.
Want to take a step in the right direction? Come grab one of my programs and get started today. It may just be the start of something really special.
