Please Stop Checking Your Heart Rate so Often.
Your heart beats faster when you’re working out so it’s a good way to know if you’re exercising enough… right? Well, not really. Your heart rate is just a good indicator of effort in certain types of exercise. And it can even lead you down the wrong path if the numbers are not properly calibrated.
Don’t rely on heart rate tracking to burn calories
If your fitness tracker tells you that you’ve burned a certain number of calories in a workout, it will base that number on your heart rate (plus a few personal details like your height).
It’s basically true that the higher your heart rate while doing a cardio workout like running, the more calories you burn during that workout. But your watch can’t tell when your heart rate is high for another reason (such as being nervous or overheated) in addition to your effort level.
This measure is also notoriously inaccurate for some activities. Running and cycling are fairly easy since you’re doing the same movement over and over again, and since the way your feet pedal is probably not much different from how cyclists have used app makers to calibrate their formulas. But if you’re barre-training, CrossFit, or spending the day on the ski slopes, how is the watch supposed to know exactly what you’re doing and how hard it is? Spoiler: it’s not.
Adding to the confusion is the fact that calories burned during exercise don’t tell us much about total calories burned, which is something we really care about. Our body is good at storing energy in daily life when we burn a lot of calories during exercise . So you can burn 500 calories on a run and then be so tired that you burn 400 fewer calories for the rest of the day.
Bottom line, if you care about how many calories you burn, you shouldn’t worry so much about what your heart rate tracker is telling you. The best method is to simply adjust the number of calories consumed depending on whether the scale goes up or down .
Don’t worry about your heart rate during strength training
If you do a lot of cardio, you may be used to thinking of heart rate as a good measure of intensity. The higher your heart rate during a workout, the harder you work. But this does not apply to strength training.
Think about this: if you have a light weight and you lift it over and over again, your heart rate will increase and you will keep it at a high level. For example, here is a graph of my heart rate when I do a series of clean and jerks with a kettlebell for ten consecutive minutes:
It’s a hard workout and it will build some strength, but it’s nothing compared to one of my regular weightlifting workouts where I did barbell clean and jerks, clean pulls (kind of an explosive deadlift), clean-and-jerk recovery and some core bodybuilding exercises. Press. floor for a total of more than an hour. Most of these lifts were short efforts that were hard enough to make me pant afterward. These are peaks on the graph. But then I sat for a few minutes to recover, and then you see my pulse drop again.
From the heart rate charts, we can see that the 10-minute set was a steady, relatively high-effort workout in terms of cardio. I couldn’t move much faster or harder as my circulatory system couldn’t supply enough blood and oxygen to my muscles to handle the much greater effort. In terms of my lungs, this is very similar to a tempo run.
On the other hand, barbell training didn’t put too much strain on my heart and lungs, and it did little to improve cardiovascular endurance. If you were to judge these workouts by heart rate graphs alone, barbell training would seem pointless.
But the benefits of cardio are not the reason we do strength training . Strength training makes our muscles get stronger. Heart rate does not reflect how hard or difficult the lift actually is. Just by looking at the chart, I can’t tell which set was 42kg and which was 49kg; To verify this, I need to look at my training log. And if I compared this workout to the one I did a few years ago when I was less strong, it would probably look similar, although the weights would be much lighter.
It’s important to understand this distinction because if you’re judging strength training by heart rate alone, you’ll be tempted to increase your average heart rate by doing more reps with less weight, turning it into cardio. (That ten-minute kettlebell workout I used as an example? It really is the sweet spot between cardio and strength training, providing a hard workout for my heart and lungs and only a medium workout for my muscles.) If you want to get strong, you need to lift gravity , which necessarily means rest and a decrease in heart rate between sets.
Use Heart Rate to Measure Cardio Intensity—with Cautions
Now we come to the fact that heart rate gives good results, that is, it measures the intensity of cardio activities such as running and cycling.
So how do you turn the number of heartbeats into a measure of intensity? The easiest way is to use an app that converts your heart rate into a set of heart rate zones . In a five zone system, if you go for a LISS (low intensity at steady state) run, you should expect your heart rate to be in zone 2 most of the time.
These zones are useful when training because each zone has a slightly different training effect. Zone 2 workouts are great for building aerobic capacity without getting too tired. Zones 3 and 4 teach your body to work a little harder, but these zones are hard to work that much. So if you’re going on a long run, you might want to wear a heart rate monitor to make sure you stay in zone 2 to get the benefits you want; on another day, you can do a shorter workout where you ride the line between zone 4 and zone 5 to train your body to handle heavy effort.
However, you don’t need to measure your heart rate to be able to train at these levels of effort. Before smartwatches and heart rate monitors were commonplace, trainers advised runners to start with an “easy jog” and recreational runners tried to keep their pace “conversational”, literally at an effort level where you could breathe easily enough that you could hold on. talk. Meanwhile, if you’re doing high-intensity intervals, you don’t need a heart rate monitor to tell you when you’re running your best. You can feel it.
How to train with heart rate, if you still want to
If you’re just getting into cycling, running, or other stable cardio activity, you can train by effort level rather than relying on heart rate. And if you want to pay attention to heart rate, I would advise you to just pay attention to what heart rate you see at each level of subjective effort:
- What number do you see when you are walking or warming up, but not yet putting in much effort?
- What number do you see when you’re exercising at a pace where you can still easily carry on a conversation?
- What number do you see when you’re working at a level of effort that’s hard to maintain, but that you could do for maybe half an hour or more if you really needed to?
- What number do you see when you go all-in? (Perhaps there is no number at all, because you are too tired and distracted to look at the clock, but you can check later.)
These numbers roughly correspond to Zones 1, 2, 4, and 5, with Zone 3 somewhere between that easy pace and grueling, but I can resist.
The reason I ask you to notice rather than count is because when you are new to exercises, your calculations are likely to be wrong. The standard description of heart rate zones is expressed as a percentage of your maximum heart rate, but if you’ve never run as hard as you can and vomit on race day, you have no idea what your maximum really is.
There are various formulas to find your maximum; the simplest is to subtract your age from 220 so that a 30-year-old person has a maximum heart rate of 190. The problem with this approach is that this is a universal formula that fits almost anyone .
Here’s an example: I’m 41 years old and my actual maximum heart rate is somewhere north of 205. If I were to rely on the formula, a heart rate of 152 would be in zone 4, although I actually know it’s a good easy pace. for zone 2. for me. When I did this ten minute kettlebell set, I spent half of it with a heart rate above what the formula thinks is physically possible for me. And then some people have a lower maximum heart rate than the formula predicts and have the opposite problem. They will choke, choke, their legs will burn, and their watch will show that they are in Zone 3. This is also wrong. Training with incorrectly calibrated zones can lead to exhaustion or undertraining.
Your heart rate will also change depending on your body position, for example, as I noticed that when cycling, the heart rate cannot be as high as when running. (Swimming when your body is in a horizontal position tends to score even lower.)
So don’t worry about the exact pulse at first. Higher means your cardiovascular system is working harder; lower means it’s easier for you. See how your effort feels at a given heart rate and adjust “max.” in your app settings to any number that makes the zones reasonable. And remember that heart rate is only a tool to help you get in the right frame of mind for your workout. Your body knows how hard it works, whether you’re wearing a smartwatch or not.