Everything You Want To Know About Calories & Max Heart Rate

Understanding Heart Rate & Calories at STRIDE

Are you using your Stride workout data to maximize your fitness? Or do your eyes glaze over when you hear the words "Heart Rate Max"? The information you collect from each workout can be a terrific training tool, but only if you understand it and use it. Read on to have some of your most frequently-asked questions answered. 

I want to lose weight. Should I try to keep my heart rate at 60-70% to be in the “fat-burning” zone?

The term “fat-burning zone” has been a source of confusion for a long time. While it’s true that you burn calories from fat in your lower zones (specifically Zone 1 and Zone 2), working out in that zone is not your quickest road to weight loss.


In lower heart-rate zones, your body burns more fat calories and at higher heart rate zones your body burns more calories from sugar. But, most importantly, at higher heart rate zones, you burn MORE calories altogether. And ultimately, weight loss comes down to burning more calories than you ingest - regardless of where they come from.

From the Polar blog, “When you’re exercising at a low intensity, you may burn fat, but you stop burning anything as soon as you’re finished working out. But when you up the ante – say with a HIIT-style boot-camp class or interval run or ride – you create what’s known as the afterburn effect.

The afterburn effort, also known as “EPOC” (that’s excess post-exercise oxygen consumption) is the metabolic disturbance that burns calories even after your workout is over. (So yes, you’re still burning calories when you’re back home on the couch on your third straight episode of Stranger Things.)

And in this case, science has your back. A University of Southern Maine study looked at the total calorie burn of low-intensity exercise vs. high-intensity exercise, and found that the difference in calorie burn was substantial. The low-intensity group that cycled at a steady rate burned 29 calories in 3.5 minutes, while a group running 15-second sprints only burned four calories. But when it came to the afterburn, the cycling group only burned an additional 39 calories, while the runners burned 65. The cycling group worked out almost five times longer than the sprinters, and the sprinters burned 95 percent of their calories after the workout was complete.

So while sticking to Zones 1 and 2 can be enjoyable and the best way to enjoy a long, chatty run with friends, getting into the higher zones is probably more effective for weight loss. ‘I’ve always found that the best way to drop fat and lose weight is actually to train in short, hard intervals that max out your heart rate,’ says Baugh. ‘Lower-intensity intervals can be useful, but they’re generally less effective for weight loss.’”

Is my heart rate a measurement of how hard I’m working?

While your exertion (how hard you’re working) and your HR Max (how fast your heart is beating) are often related, they are not direct correlates. Technically, your heart rate is a reaction to the work being done, not a measurement of the work. Your HR Max in each workout is affected by a number of factors other than how hard you’re working, such as genetics, hydration, caffeine, sleep, body temperature and a number of other factors.

That being said, there is an approximate relationship between HR Max - as you exert yourself and/or sustain a level of exertion, your heart rate will speed up. As your heart gets stronger, you will be able to sustain high HR zones for longer, and you will be able to recover quicker.


How is my Max HR determined?

Stride’s Polar HR system measures your Max Heart Rate using the equation 220 - your age. For most, this gives an accurate Heart Rate Max. For some people, the estimate will be slightly off, so they will see an unusually high OR low % of Max Heart Rate in class. Don’t worry - this is an easy fix when you notice it. Simply tell the front desk staff and they can adjust your Polar settings.

Here are some other things to know about your Max Heart Rate:

  • Max Heart Rate is determined by genetics.

  • It is not an indicator of fitness. A 50-year-old elite athlete and a 50-year-old who hasn’t worked out in 10 years may have the same Max Heart Rate.

  • Smaller people tend to have a higher Max Heart Rate than larger people.

  • Your MHR can decline with age

  • Training will probably not change your Max Heart Rate

In class today, my Max Heart Rate was at 107% - am I in danger?

No! Your heart rate max is exactly that - a MAXIMUM. Your heart rate max represents the point when your heart can’t eject blood effectively anymore, at which point self-preservation kicks in and you slow down. Thus, it is not possible to exceed 100% - your body’s natural will to survive would never allow it.

If you see your HR Max go above 100% it simply tells us that your max heart rate setting in Polar was set too low for your heart. And that’s easy to fix! Simply tell the front desk and they can help you adjust your settings.

How are my calories calculated?

When you’re wearing a Polar heart rate monitor, your calories are calculated using your weight, height, age, gender, and your individual maximum heart rate (HRmax). Generally, men burn more calories than women (so unfair!), people who weigh more burn more calories than their lighter-weight friends, younger people burn more calories than older people, and harder exertion burns more than moderate exertion.

Because your Max Heart Rate is used to calculate your caloric burn in every Stride class, it’s important to let us help you adjust your HR Max setting if you believe it to be inaccurate. If you can’t measure it, you can’t improve it!

Questions? Email us!

Leanne Pedante