Heart Rate Training

What do all these colors and numbers and percentages mean?!?


Lots of gyms are implementing the tool of heart rate training these days. The two most prominent ones in my mind are Orange Theory and the gym I work for, 9Round Kickboxing. It really is a valuable thing to know and understand while you're working out so that you can get the most effective workout possible. But, like, how the heck does it work..?

Heart rate monitors measure your actual heart rate, your calories burned, and your percentage of your maximum heart rate throughout your workout. These zones vary from device to device -- some have 4, some have 5, some are blue, some are yellow, etc. -- but the idea of increasing levels of intensity is the same. As you approach the higher end of the zones you are working closer and closer to your hearts maximum potential.

The zones are ordered by the percentage of your VO2max, which is your heart's maximum capacity to pump blood out and supply oxygen to the body/muscles. Obviously, there is a cap. At some point your heart can't pump anymore any faster. And, as you can imagine working too closely to this cap too often can be really tough on your body -- and your heart, specifically.

Using a device to track your heart rate in real time allows you to adjust the intensity level of your workout to avoid working too hard for too long and, of course, to work hard *enough* to reap the benefits. It gives you a tangible number to work with (rather than just guessing), and of course having your calories counted is a great motivator.

The image above gives a good, brief explanation of each zone, and I really like the analogy of a car... Imagine driving a car at 100+ miles an hour all the time. (Aka: running it very near it's maximum. Think of this like being 90% of the car's VO2max.) Yes, the car CAN do it, but it puts a lot of undue stress and wear and tear on the engine. It's certainly not in the best interest of the longevity of the vehicle.

Well, your body is much the same. Yes, it CAN perform at maximum capacity all the time if you force it to, but it's making a lot of sacrifices to do so. Your body is adaptive, and it's sole goal is survival. So it will find ways to survive like using alternate fuel sources, forcing you to stop by shutting down and causing you to pass out, etc.

It's quite counterintuitive, actually, to work in the 90%-100% for most or all of your workout. (This is not to say you should never touch this zone. But you should do so carefully, intentionally, and incrementally.) To avoid injury, overtraining, nausea, fainting, illness, and burning off all the muscle you're working so hard to build, you'll want to limit the amount of time spent in that top zone. 

Generally you'll want your workout to look like this, based on the attached image above:

WARM UP in the blue to green zones for 5-10 min. (50-70%)
WORKOUT dominantly in the yellow and purple zones. (70-90%)
OCCASIONALLY hit that red zone for ~10-30 seconds at a time. (90-100%)
COOL DOWN to recover back to the green, then the blue, then the "grey" zone which is not pictured. (70->60->50% and below.)


Let's use one of my workouts to illustrate this:

The heart rate monitor I used is called Pulse and is made by 9Round Kickboxing. It uses a scheme of 5 zones, which are as follows:

GREY: < 60%
BLUE: 61-70%
GREEN: 71-80%
YELLOW: 81-90%
RED: 91-100%

The workout itself that I did was 30 minutes long, and you'll see that my total workout time on this feedback graph was 37 minutes. This time includes a few minutes prior to and after the workout where I was either getting ready to start or letting my heart rate recover back to resting. Let's examine it!

A snapshot of one of my own workouts using heart rate training technology. 

Getting started...

There are 3m19s spent in the grey zone. This is a non-working zone. Aka: you are either just starting your workout or it's over. 

There are 2m13s spent in the blue zoneThis is the warm-up/cool-down zone. Aka: your blood is pumping, but your either ramping up for your workout or coming down from it. 

These two zones don't provide a huge amount of benefit cardiovascularly or for muscle strength/endurance, and you won't burn many calories in them. They are simply phases you must pass through in order to get to the working zones.

Now we're talkin'...

There are 14m02s spent in the green zone, the first of the working zones. This zone entails a moderate level of exertion. You're breathing, you're sweating, but you're not overworking. Your body uses oxygen to create energy in this intensity range (aerobic exercise) and is benefiting cardiovascularly. This is a great zone to workout in for endurance, hearth strength and health, and to burn some calories. 

There are 17m21s spent in the yellow zone, or what I call "the SWEET SPOT." This is zone where you're benefiting the most! You're breathing heavy. You're starting to drip sweat. You're feeling challenged. You may have to stop and take a quick break. Your body is still using oxygen to produce energy here (at least for the lower portion of this zone), and working at this intensity level can improve strength, endurance, and cardiovascular capacity. Since you're working a bit harder now than in the green you are burning more calories, and as a result, you're burning off more fat here than in the green zone!

Lastly, there are 22s spent in the red zoneThis is the highest intensity range. You are beginning to struggle for breath. Your muscles are feeling extremely fatigued. Speed, coordination, and agility are beginning to decline (aka: form is getting sloppy). These effects are exaggerated as you climb closer and closer to the top of this zone. Your body is now beginning to acquire its energy anaerobically, which means it is no longer using oxygen. It needs a quicker pathway for energy, because you are burning it off so quickly. In this zone you will be burning more calories than in the green or yellow, but if you spend too long here your body will begin to source its energy from protein... Read: your body will begin using your muscle to fuel itself, which is no bueno. We work so hard for our lean muscle mass. We don't want to be burning it off!! 

Now, with all that being said, there are benefits to spending small bursts in this zone. It can greatly improve sports performance, power, reactivity, and, honestly, mental grit. When used appropriately it can also increase hearth strength by pushing it to its max capacity briefly and then quickly allowing it to recover. 

As mentioned multiple times, you do not want to spend too much time in this top zone! 

The snapshot of my workout above is extremely ideal when it comes to heart rate training. I've got an adequate amount of time warming up and cooling down in the grey and blue zones. I spent the majority of my working time in the green and yellow zones pushing myself appropriately. And I spent the least amount of time in the red zone -- and that 22 seconds was definitely achieved by  separate short bursts -- in order to improve my overall performance and power as an athlete. 

The Takeaway

Heart rate training can shed light on exactly how hard you're working while you exercise. If you feel like you aren't seeing results maybe you're not working hard enough, or maybe you're working TOO hard. But until you actually see the numbers it's hard to tell what adjustments you need to make.

The biggest benefit of wearing a visible monitor during your training is being able to control your heart rate in real time. You hit the red? Let yourself recover! You've been in the green for 5 minutes now? Push a little harder! You're yellow? Keep doing what you're doing! And so on and so forth.

Wearing a monitor has honestly revolutionized my workouts, so I strongly suggest wearing one! But, it's useless without understanding how it works for you, so please let me know if you have any questions about the info provided here! I'm happy to help. :)