Heart Rate Training - By Henry Toraño

Heart Rate Training

By Henry Toraño

Heart rate training is by no means a new concept. We’ve seen it in the endurance world for decades. It even made its way into mainstream fitness. Nowadays, you can see people of all fitness levels wearing a chest strap or monitoring via a wrist wearable device such as Fitbit and Whoop, amongst others. As the fitness scene has evolved in recent years towards functional training, there has been a little confusion about why we’re not applying heart rate training in these modalities. It’s not for lack of trying, as I frequently see people questioning the principles or attempting to implement. So, let’s look at the factors that need to be considered for its use and why I personally believe that it is NOT transferable to functional fitness.

Heart Rate Training – Exactly what is it?

The first thing you need to know is what we actually mean by “heart rate training”. Heart Rate, in itself, is the amount of times that one’s heart beats in one minute. Thus, it is measured in beats per minute (bpm). By determining an individual’s max heart rate we can establish what is known as heart rate zones. These zones are then used to define training intensity. While there may be very slight variations depending on coaching philosophies, here’s a pretty acceptable illustration of these zones:

What’s your Max HR?

Here’s where things start getting a little blurry. The first answer you will get to this question is: 220 -  your age = your Max HR. This is what most HR tracking devices use to establish your training parameters. Yes, there are more advanced ones that may prompt for resting HR tests, adjust for gender, and even for height. But even in these, the difference between their metrics and the “220 – age” concept are very similar. Due to the fact that this is in large part a guesstimate, you will hear people say that the truly accurate way to know your max HR is to do a “Stress Test”. In a stress test, the testing subject is hooked up to an ECG and is guided through a series of efforts on the treadmill. Intensity is periodically increased, in speed and inclination, as HR is measured. This is very tough test, as max HR is determined by value reported at the point when output can no longer be sustained. Iterations of this test can be performed outside of the lab, and while they may not be as precise, they can be a lot more reliable than estimating via age. But, like I said, things get blurry.

Effect of Body Position on Heart Rate

As already mentioned, heart rate training has been widely used in endurance training. When we think endurance, two modalities come to mind: Running and Cycling. As those two got popular and humans got creative, we added swimming to the mix. Not that swimming wasn’t already around, but someone decided it would be a good idea to mix them all up into one single sport: triathlon. What happened next was pretty mind blowing. It turns out that athletes began to notice that HR zones in one sport did not correlate to Rate of Perceived Exertion (RPE) in another sport. In layman’s terms, training at a HR of 80% on the bike felt a lot harder than 80% on the run. This is not to imply that one is harder than other, but rather that the physiological response to one is not quite the same as the other. Bring swimming into the mix, and while HR and RPE are a lot more comparable to the cycling, it’s still slightly lower in the swim. Upon coming up with a testing protocol (similar to the stress test) to perform on the bike, we came to learn that max achievable HR on the run tends to be higher than that of max achievable HR on the bike. 

Now, there’s several working theories for this. One of the more accepted ones is that when you are running, you are fully vertical. When you are seated on the bike, you are somewhat vertical, but your feet and hands are a lot closer to the heart’s level, compared to when you’re running. When you swim, you are fully horizontal, hence the entire body is at the heart’s level. Son when you stand, the heart needs to pump more frequently to fight the effect of gravity and be able to push blood to the extremities. This makes perfect sense to me. However, theres been other studies that suggest that gravity is not the cause, but rather the actual position of the legs. If you want to geek out, here’s one of those studies:

https://physoc.onlinelibrary.wiley.com/doi/abs/10.1113/expphysiol.1933.sp000588

Regardless of the reason, we can all agree that when you stand, HR spikes compared to when you sit or lie down. So due to these differences, triathletes frequently perform max HR tests for every sport, to better establish training parameters in each. So, for somebody doing a triathlon, they may be swimming at 75% max HR, cycling at 80% max HR, and running at 85% max HR, all the while feeling like they’re exerting the same amount of energy. Heart rate is different, but RPE is the same.

Other Factors that Affect HR

Let’s say that you’re training for triathlon and have set your 3 sets of training zones. You’re a lot better equipped now, but there’s STILL more nuances! HR can be affected by many things. Temperature, nutrition, hydration, sleep, emotions, time of day are just a few of those factors. So training zones still need to be taken with a grain of salt, as RPE may be significantly skewed due to any of these factors relative to what you’re seeing in your HR monitor.

Application to Functional Training and Mixed Modalities

It took a while, but we’re finally here. You’ve already learned that every sport/modality requires it’s very own testing protocol to determine max HR for that particular modality. Well, the thing that we love most about functional training is the vast variety of movements that we can perform and the endless combinations that we can make of them. Now think about all the different tests that we would have to perform to be able to determine HR zones for a mixed modal workout. Consider that there is no set position of the body relative to the heart. These workouts may include a run (standing), pushups (horizontal), and GHD Situps (heart goes from under heart level to above heart level). It would be impossible to accurately establish HR parameters for this. If you’re thinking that it can be done, consider that by changing the rep scheme of that very same workout we could drastically change the amount of time spent in each of the positions. Perhaps now you can start making sense of why burpees absolutely jack up your heart rate: lie on the ground, stand up, lie on the ground, stand up….. you get the point. 

It’s Not All Useless!

While using heart rate monitoring to dictate training parameters is really not as implementable as theory would suggest, there ARE good applications for it. I’ve had clients correlate HR and power output to gauge adaptation. For example, have somebody get on a rower and sustain an avg pace of 2:10/500 for 20:00. Track average HR during this interval. Let’s say it’s 145bpm. Next week, hit the same session, but now for 25:00. Next week, 30:00. Each subsequent week, continue to track average HR. If average heart rate INCREASES every time the interval gets longer, this could be an indication of that set pace (2:10/500) NOT being sustainable/aerobic. On the other hand, if each subsequent week average HR is sustained or DECREASED, it could be a sign of positive adaptation, where the individual is learning how to use oxygen for fuel and gaining fitness throughout the process.

I hope this has served to clear up some of the intricacies and myths around heart rate training. In the end, I believe that tracking data is very important. Heart Rate can be one data point that is tracked, but I’d stop short of saying it should be the determining factor in pacing or setting training intensity. If you are going to use it to set zones, at the very least do due diligence and test for max HR in the particular modality where it will be implemented. I’ll Leave you with a testing protocol that you can use.

10-15 min @ easy effort

Rest 2 min

1 min @60% Perceived Effort

Rest 1 min

1 min @75% Perceived Effort

Rest 1 min

1 min @90% Perceived Effort

rest 2 min

1:00 @ ABSOLUTE MAX EFFORT

The highest HR recorded during the interval is your max HR on that component