The chest strap heart rate monitor is a great tool. I think every hunter who’s serious about improving their endurance should own one and use it during most conditioning sessions. But sometimes we head out the door and forget to toss it in the truck. And other times, it’s just not practical, like when we’re hunting but still want to keep tabs on how hard we’re working so we don’t gas ourselves out. Each of those scenarios requires us to learn how to dial in on how hard we’re training using feedback from our bodies instead of following the heart rate read out from our chest straps.

Comparing and contrasting how your body feels with your heart rate is also an important skill. Training zones are moving targets dependent on hydration, recovery, altitude, and fatigue. For example, if you’re under recovered, your heart rate zones shift down. So, while your heart rate monitor might tell you that you’re in Zone 2, if you’re under recovered you might actually be in a higher heart rate zone. That’s where feedback from your body comes in. You compare and contrast it with your heart rate to determine if you need to tone back your effort, even if your monitor tells you that you’re in the correct training zone. It’s a hugely important skill. 

I’m giving you simple ways to develop that skill. Below, you’ll learn three methods for tracking your training intensity by paying attention to what your body is telling you.

Rating of Perceived Exertion (RPE)

RPE is how you’d subjectively rate how hard you’re working at a given time. It includes how hard you’re breathing, how your muscles feel, and how hard your heart is beating. The Borg Scale is the OG, and its ratings run from 6 to 20. But I think it’s a little too complicated. The Modified CR Scale runs from 1 to 10, making it much easier to understand and use in the moment while training. Let’s cover how the Modified CR Scale works and connect it with training zones.

Here’s the scale as we use it:

0 = Rest

1-2 = Very easy

3 = Easy

4-5 = Moderate

6-7 = Somewhat difficult

8-9 = Difficult

10 = Max effort

Here’s how the scale corresponds to training zones for most hunters:

Zone 1 = typically about 3-4

Zone 2 = typically about 4-5

Zone 3 = typically about 6-7

Zone 4 = typically about 7-8

Zone 5 = typically about 9-10

It ain’t perfect, but it works. 

And there are some things that affect the scale you need to keep in mind.

Recovery, fueling, sleep, and stress all affect how difficult training feels. If you’re under recovered, training feels more difficult. Fueling while training, especially during long aerobic workouts, decreases RPE. If you’re under-slept or stressed, everything feels harder. 

Monitoring your pace puts this all into context. For example, if you can normally run a 10-minute mile at a 4 RPE, but that pace feels like a 6 on a given day, it’s likely one of the above factors is contributing to the increase in perceived effort. That means you ought to move slower that day to avoid digging yourself a deeper hole. 

It also helps to sync RPE with your heart rate while wearing your chest strap during a workout when you’re wearing it. Cross reference your RPE, pace, and heart rate across multiple workouts—ones when you feel like a superhero, ones when you feel normal, and ones when you feel like 10 pounds of shit stuffed in a 5-pound bag. This improves your skill. You get more in-sync with the feedback your body gives you while training.

Respiration

How hard and fast you’re breathing correlates with your body’s need for oxygen or its oxygen debt. The harder and faster you’re breathing, the greater your oxygen debt. A bigger oxygen debt means you’re working at a higher intensity. That makes monitoring your breathing a decent way to track your training intensity. You can use the talk test to do that. Here’s how it works.

Easy nasal breathing = likely Zone 1 / low Zone 2

Get a full sentence out before needing to breathe = likely Zone 2

Can say a few words = likely Zone 3

One word, maybe two = likely Zone 4

Can’t talk = likely Zone 5

Leg Fatigue/Burn

How your legs feel while conditioning gives us some insight into how your metabolism is producing energy. However, this only works as a gauge as a training session drags on. It takes a while for fatigue to accumulate. 

If your legs feel light and good, you’re likely in Zone 1 or low Zone 2.

If your legs feel tired, “dead,” or only have a slight burn, you’re likely in Zone 2 or Zone 3.

If there’s a lot of burn, you’re likely in high Zone 3 and creeping into Zone 4.

How to Use These Internal Tools to Gauge Training Intensity

The best thing to do is check in with all of them and cross reference. Check in with your RPE and compare it to how your legs feel. Then pay attention to your breathing. Do they all coincide? Then you have a pretty good idea how hard you’re working.

Start by doing this while wearing your heart rate monitor during a workout when you feel fresh. Reference your heart rate in comparison to all of the subjective measures above. Then, do it again on a day when you’re not so fresh. This covers your bases so you have a good idea how to judge them all depending on how you feel going into a workout.

Learn to Internally Judge Intensity

Chest strap heart rate monitors are great, and we should use them much of the time. But it’s important to develop the skills necessary to judge training intensity without one. You won’t always have one on you when training, and there’s no need to be the nerd wearing a heart rate monitor while hunting (unless you’re doing it for your own little research project).