Understanding heart rate and health

Your lungs are begging for air. Your legs are pumping. Sweat has beaded across your forehead and drips dangerously close to getting in your eyes.

As you bear down on the treadmill, your heart feels like it’s singing in your chest (or wait, is it crying?). You look down at the metal handles and decide to grip them to measure your heart rate, curious as to whether this workout is as effective as it feels.

This has to be good for my body — my heart — right?

The pixels pop up on the screen, indicating that your heart is ... well, it’s pumping. That’s for sure. But in reality, you have to admit to yourself that you aren’t really sure what the number on the screen means. How do you know your heart is really pumping at a good rate?

What can your heart rate really even tell you?

Resting heart rate and your health

A person’s resting heart rate is how many times their heart beats per minute when they are otherwise resting or inactive.

A healthy resting heart range, according to local Sarasota cardiologist Dr. El Shahawy, is anywhere from about 50 to 75 beats per minute.

“At rest, you should have a nice heart rate in the 70s. At max, in the high 70s,” he said. “Over the years, we’ve learned that the lower the resting heart rate, the better you are.”

Typically, he says, resting heart rates as low as 40 or 50 beats per minute are indicative of a healthy heart, so long as a person achieves that rate through regular exercise or an otherwise healthy lifestyle.

A consistently high resting heart rate, on the other hand, can indicate fever, infection, high levels of stress or the presence of diseases that affect the heart.

After all, the heart shouldn’t be straining to pump blood while the body itself is just sitting at a desk or on the couch.

Maximum heart rate and knowing your limits

Maximum heart rate is the maximum number of times the heart should beat per minute while engaged in exercise. To calculate this number, Shahawy says a person can typically subtract their age from 220.

For example, if somebody is 50 years old, they wouldn’t want their heart rate to exceed 170 beats per minute while exercising (220 - 50 = 170).

But while this formula can at least give a rough estimate of maximum target heart rate, Shahawy also warns it is not entirely accurate. In reality, maximum target heart rate is based on age and gender, as well as other factors, such as how in shape a person is or whether they might have health conditions that affect their ability to push themselves.

Thus, it is important to never exceed that number.

“Anybody who does exercise in excess of [their] maximum heart rate is looking for trouble,” Shahawy said. “Any doctor won’t do an exercise test with a patient without knowing what [their] maximum heart rate should be, otherwise that can cause a problem. You should never ever try to go on a treadmill or exercise program without knowing what your exercise maximum heart rate is.”

For this reason, he stresses that people need to see their physician to know what their heart’s true exercise tolerance is. Otherwise, it can be easy to accidentally surpass that number and do harm to the heart.

If a person exceeds their maximum heart rate, they could be at risk of having a heart attack or otherwise injuring their cardiovascular system.

That being said, the time it takes to reach the heart’s maximum rate is also important. If a person’s heart rate tends to immediately skyrocket while at the gym, for instance, they should probably contact their physician.

“If you achieve your max heart rate at a low exercise load ... well, that’s no good. So, if it takes time to reach it, that means you are ‘conditioned,’” Shahawy said. “Exercise conditioning gets you to be able to get a lot of exercise without [your heart rate] jumping right away.”

Heart rate zones and exercise

Speaking of exercise conditioning, knowing where and when to stop isn’t the only thing people should be concerned about. People should also be aware of what different heart rate “zones” or “ranges” they can reach. This way, they can effectively meet a variety of fitness goals at a healthy pace.

“Ideally, reaching 85% of your expected maximum heart rate would be a good way to push yourself,” Shahawy said. “While you can push to your max heart rate, I don’t think you would like that stress.”

Similarly, the American Heart Association defines reaching 70-85% of a person’s maximum heart rate as “vigorous” exercise, where it defines reaching 50-70% as “moderate.”

So, let’s break that down.

Assuming somebody is 50 years old, they would need to know their maximum heart rate is 170 beats per minute. But what if they wanted to engage in some vigorous cardio to lose weight? In that case, they’d want to aim to reach an average heart rate of around 120 to 145 beats per minute.

But if they’re just looking to ease their way back into shape, build on an exercise foundation or just take it easy for the day, reaching a moderate heart rate of 85 to 119 beats per minute should be just fine.

In all, though, Shahawy encourages people to find a form of exercise they actually like.

After all, it doesn’t matter how intense or beneficial a workout trend may be — if it’s a form of exercise a person hates, their body isn’t going to reap the benefits because they’re putting themselves under stress.

Instead, even if it’s considered a “less demanding” fitness outlet, a person should always opt for something they enjoy.

“If you’re doing exercise under stress, that’s also no good,” Shahawy said. “Your heart rate is going up, but it’s not good in the long run. Fun exercise is always good.”