Chances are, if you’ve been to enough fitness classes, you’ve heard the phrase “target heart rate” tossed around. But what does it really mean? Simply, your heart rate is the number of times your heart beats per minute, according to the American Heart Association (AHA). Normal and healthy heart rates vary among different people, and there are a few key things to remember when determining your personal goals.

Learn how to measure:

Doctors’ offices are equipped with fancy, digital machines to read your heart rate, but you can get a pretty accurate on your own. Just place the tips of your first two fingers over your pulse (on either your wrists, inside of your elbow, side of your neck, or top of your foot) so that you can feel each beat, and then count the number of beats within a 60-second span. The total is your heart rate.

Start with your resting heart rate:

Heart rate isn’t just something to be measured at the gym—knowing your resting heart rate is an important factor in understanding your target number during exercise and recognizing when there may be a problem. Measure your resting heart rate when your body is inactive (sitting or lying down), you’re not sick, and you’re calm. According to the AHA, the average normal resting heart rate is between 60 and 100 beats per minute. For those who are incredibly fit, that number could dip to 40.

Know your maximum heart rate:

On the other end of the spectrum is maximum heart rate, or your beats per minute when you’re exerting yourself. Maximum heart rate decreases with age, and is approximately 220 minus your current age, according to the AHA. If you’re 30 years old, your maximum heart rate would be 190.

Determine your target heart rate:

Your target heart rate should be about 50-69% of your maximum during moderate activity, and 70-90% during intense exercise. Don’t want to do the math? The American Cancer Society website offers a target heart rate calculator tool to take out the guess work. If you go above your target heart rate, you’ll overexert yourself and could trigger any underlying heart health issues. If you find yourself consistently below your target heart rate zone, even when working out pretty intensely, it may just be a sign of your level of fitness, as your heart doesn’t have to work as hard to keep up its steady beat. Chances are, if your resting heart rate is a bit on the low side of normal, your target heart rate will be too, and vice versa. But fitness isn’t the only thing that affects the number…

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Be aware of other potential factors:

Yes, a low heart rate may mean a person is extremely fit, but that’s not a blanket rule. Some people in amazing shape still have higher heart rates, while others who don’t exercise much could be on the lower end. This could be in part due to a few other factors that affect the number, according to the AHA:

  • Medicine: Most commonly, adrenaline (beta blockers) has been known to slow the pulse, as do some blood pressure medications, while high doses of thyroid medication can increase heart rate.
  • Temperature: Dealing with a sweltering summer? Your heart struggles with the heat and humidity too, and reacts by pumping more blood, in turn increasing your heart rate.
  • Body Position: If you’re lying on the couch watching TV, your heart rate will probably be on the low end. But if you’re walking around the house doing chores and going for a walk to the grocery store, your pulse could increase.
  • Emotions: Stress and anxiety can have an impact on your heart rate, too, as those unsettled emotions can keep your heart beating pretty fast.
  • Body Size: In general, size and weight doesn’t affect heart rate, but those who are obese may experience an increase.

The better you know your own body and resting heart rate, the more likely you’ll begin to notice when something is off, so try to measure both your resting and active beats per minute on a fairly regular basis. If you have any existing heart conditions, or experience any episodes of inexplicable slow or fast heart rates (which may come with dizziness and weakness), consult your doctor to determine if there’s any cause for concern.

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