Counting Calories with a Chest Strap Heart Rate Monitor

Published 2.3.2026: So I wear a chest strap heart rate monitor (HRM) when I work out at the gym. The gym gave me the monitor (well, sold it to me) at some point in my journey. Obviously it measures my heart rate, using the formula 220- my age.

Which is hardly fool proof. Nowhere in the app that comes with the HRM can I find away to enter my weight or my height, which I would think we make a difference caloriewise. To be clear, the answer to the question is an HRM an accurate way to track calories is NO. Doing a quick google search yielded that answer pretty quickly.

Chest strap HRMs are more accurate than wrist worn HRMs for calories (they all do a decent job of tracking heart rate… and as that’s what they were designed for, that’s a good damn thing) but HRMs chest or wrist do not do calories well. Calories, it turns out, are pretty difficult to measure precisely.

In a lab, doubly labeled water is used to measure total energy expenditure during a day, there is no way for the technigue to say how that calorie expenditure breaks down between basal metabolic rate (BMR), thermic effect of food (TEF), Exercise Activation Thermogenesis (EAT, ie deliberate exercise) and Non-Exercise Activation Thermogenesis (NEAT, all other motion other than exercise). I’m quite happy to see that researchers have decided that step count (walking around) belongs in NEAT rather than EAT. That hasn’t always been the case. I didn’t include any links here because I think this is all common sense.

Calories can also be measured by researchers in a metabolic ward, only some of which involves doubly labeled water. There is also something called a “metabolic hood” that can be used, but these are specialized equipment used by researchers, not the everyday joes. There are other research ways as well, this list in not intended to be all-inclusive.

In any event, I wear my HRM at the gym, but nowhere else. I did wear it once hiking, but that was more of a pain than it was worth and once when I had to clear snow and couldn’t get to the gym because of the aformentioned snow. In general, the HRM is only for the gym (for me). Obviously, the HRM gives me the heart rate during various activities I do at the gym. It also calculates the MEPs I allegedly use and the number of calories I allegedly burn.

My feeling about the calories is if you compare values by the same sensor (and I do) then the trend of calorie burn is probably accurate, even if the absolute number is not. So I can’t say that such and such workout burned this many calories, but I can say that the number of calories burned in this workout was more or less than another workout. Is that correct?

If the error is not random, but always there and constant, I suppose it would be accurate, though not precise. so what is the accuracy of my HRM? A brief foray onto Google indicates that mine is not a high end version, which is hardly surprising given that I got it from my gym. I have no way to claibrate the HRM, either for calories or any other number it spews out.

What is a MEP?

A MEP is basically meaningless. I thought that the HRM was calulating MET or metabolic equivalents, which would relate to calories by some formula. But MEP, or MyZone Effort Points has no meaning beyond the proprietary (actually it’s pretty basic) calculation the company (MyZone) uses to caclculate it from the 5 “zones” of heart rate it defines. The “zones” themselves relate to nothing; they are completely arbitrary. The gym that I belong to is currently having a challenge to get to the most MEPs… for whatever that’s worth.

I was all excited to define MET and do the caclulation, only to realize that 1) it’s more complicated than I thought and 2) that’s not what my HRM is tracking in any event.

So the bottom line here is that I am tracking my heart rate as I exercise and it does give me a number for the calories, though that number is off by some (unknown) percentage. I think I will do the same as I do for the fat mass percentage measured using a bioelectric impedance scale. The trend, rather than the actual number will be my guide. If the number of calories is up, then I will assume that I burned more calories, and vice versa. MEPs are not worth tracking at all. And if nothing else, higher heart rate leads to greater calorie counts, which makes intuitive sense to me.

Cardio sessions

My cardio sessions (2 dedicated days of 60 minutes + three days of 30 minutes after my resistance training workouts) are where my heart rate really goes up. Depending on what lefts I’m doing and how heavy the weight is, my heart rate might be elevated. But generally, my current trainer (I’m on my fourth one now, though number 3 didn’t really train me as he had a new job almost immediately) doesn’t really program any cardio— not even the battle ropes.

On my two days of dedicated cardio, I have taken to doing the 12-3-30. In the 12-3-30 workout, you walk for 30 minutes at an incline of 12 and a speed of 3. That’s a decent workout. Clearly, as I’m walking for 60 minutes I don’t start off at that incline. Instead, I walk for ten minutes a bit at a lower incline, then 30 minutes at an incline of 12, and then I walk the remainder of the hour as a cool down, lowering the incline by three every five minutes.

The true purpose of the cardio days is to improve my heart and circulation. I felt like I was getting leaner by lifting, but that I needed some cardio in my program. The result is that I head to the gym five days a week, though I am splitting time between two gyms. The one in which I work with a trainer is closer my old retail shop but about 40 minutes from my home, The cardio gym is closer to my house, roughly 15 minutes away. They are owned by the same people, I think, but it doesn’t matter because it’s a chain and I can go into any of that gym.

In addition, I am trying to get 10,000 steps a day. I’ve been listening to body builders a bit when I listen to podcasts or on YouTube, and generally the cliché is that do resistance training for body recomposition, and cardio for weight loss. I would like to lose a few more pounds, but I don’t want to eat less. As a calorie deficit is required to lose weight, my hope is that by increasing my cardio and step count, I’ll create a small deficit. So that’s a bit of a personal update.