Target Heart Rate? 4 Reasons Not to Sweat It

If you wear a fitness tracker or use fitness equipment, you’ve probably noticed your heart rate going up and down with your activity. Maybe you’ve wondered what number is ideal for your fitness, or even tried to hit a “target” heart rate. 

Is that the magic number for losing weight or gaining strength?  As a cardiologist, I assure my patients that unless you’re a marathoner or a serious athlete working toward a specific goal, you need not add heart rate math to your weekly workouts.  The simple fact is determining a target heart rate can be complicated and even deceiving for most people. Here’s four reasons not to sweat over that not-so-magic number. 

1.) Heart rates vary widely.

To determine your resting heart rate – when you’re not being active – find your pulse on your wrist with your finger and count the beats for 60 seconds. That’s your resting heart rate. 

Generally, taller people have lower resting heart rates and shorter people have higher resting heart rates. It’s similar in the animal kingdom – smaller animals run higher and larger animals have lower heart rates. 

Unfortunately, this is simply a generalization. The reality is some people can have a higher or lower number compared to someone of the same height and weight. 

What’s important to remember is that what’s normal for you is normal for you. My advice is to resist the urge to compare your heart rate to someone else’s or get too hung up on that number. 

2.) Your peak heart rate is a complicated equation.  

The most common way to determine your maximum or peak heart rate is to subtract your age from 220. So if you’re 40, your peak heart rate is 220 minus 40, or 180. The logic behind this equation is that, generally, as we have more birthdays our peak rate decreases. Unfortunately, this benchmark doesn’t take into account your physical conditioning and other factors that influence your heart rate.

The most precise way to figure out your peak heart rate is to undergo a supervised laboratory test during what’s called a VO2 max test. This analysis pushes athletes to their absolute maximum, which is why it’s done under professional supervision. 

As you can imagine, you have to be rather determined to undergo this test. Unless you’re a serious athlete, there’s not a great advantage to figuring out your peak heart rate in this manner. 

3.) Heart rate is situationally driven. 

The problem with trying to calculate your target heart rate is that 100% of the time, your heart rate is going to be affected by a variety of factors, including: 

• Air temperature and humidity
• Level of hydration
• When and what you ate last
• How well and how long slept night before
• How much alcohol you consumed night before
• Current level of health condition and weight
• Emotional state 

With so many factors at play, focusing on that target heart rate can be deceiving and is not a definitive way to gauge the quality of your workout.  

4.) Target heart rate isn’t necessary for most people. 

So what should heart rate be when you’re exercising? Outside of a couple of scenarios, I don’t care what your heart rate is from a physiological perspective because I know everyone has a different heart rate, and those numbers are always fluctuating. 

If you’re trying to get fit and increase your cardiovascular health, then if you’re breathing a little harder and sweating some while working out, then there’s no need to focus on your heart rate.

It’s more important to listen to your body. If you exercise regularly, you’ve probably noticed some days are better than others. Try to notice what factors – from sleep and diet to what’s going on in your day – impact how good your workout feels.

One exception to this advice is for people who are cardiac patients who have had a recent heart attack or heart failure. We prescribe cardiac rehab so they will be monitored while exercising until the heart has recovered. This is when heart rate is essential. Once a patient is fully healed, I tell them to just listen to your body. 

The other exception is for serious athletes or those who are striving for a specific goal. In that case, my recommendation is to work with an athletic trainer who can help you take all the contributing factors into consideration.

In the meantime, simply keep moving. Make sure you’re sweating a bit and breathing a little harder. Regardless of your numbers, it will do your heart and health good. 

Reach out to your provider if you have more questions!