Understanding Your Maximum Heart Rate

If you exercise regularly, you may be aware of what your target heart rate zone is to be able to maximize the effects of your workout. Finding out what your target heart rate zone is, involves discovering your maximum heart rate. While maximum heart rate may sound scary, it's really not. It's the fastest rate that your heart will beat in one minute. 

Importance of Knowing Your MHR

Maximum heart rates are unique to each person and aren't necessarily an indicator of physical fitness. As your physical fitness increases, it doesn't mean that your maximum heart rate rises. When you're exercising, a target heart rate is about 50 to 85 percent of your maximum heart rate. To calculate your maximum heart rate, you can subtract your age from 220. When you perform a workout at this pace, your endurance improves. Knowing your target heart rate can help you correctly pace your workouts. When you exercise at the correct intensity level, you will spend your time at a pace that will help you meet your fitness goals. 

When you use the scientific way of calculating your maximum heart rate, you can have a more accurate method of determining your exercise intensity. Here are examples of different workout intensities:

  • Low intensity: 40% to 50% of your maximum heart rate
  • Moderate intensity: 50% to 60% of your maximum heart rate
  • High intensity: 60% to 70% of your maximum heart rate
  • Maximum intensity: 85% to 100% of your maximum heart rate

Cardiovascular exercise is very effective in helping you reach your target heart rate because it's aerobic exercise. Cardio is the best type of exercise for getting your heart pumping faster for sustained amounts of time. When you perform cardio workouts, you're getting your heart rate up and burning more calories at the same time. 

What Affects Your MHR?

The majority of formulas calculate a general maximum heart rate by taking into consideration your age and gender. Still, it's actually a lot more involved than that to calculate it correctly. When calculating your maximum heart rate, it's important to know that the following factors can have an effect on your maximum heart rate:

  • Age: As you age, your maximum heart rate can decline
  • Altitude: When you're exercising at higher altitudes, you can have a lower maximum heart rate
  • Genes: Maximum heart rate is affected by your genes
  • Individual differences: Even among people with similar age, gender, and fitness level, maximum heart rate can vary widely.
  • Size: In smaller people, the maximum heart rate is usually higher. It's common for women to have a higher maximum heart rate than men. 
  • Working out: Physical activity doesn't immediately change your maximum heart rate, but when people notice a change, it can get lower as the body's heart and blood volumes expand. 

You may be shocked to find out that about 50% of your maximum heart rate is influenced by your individual genes. Larger hearts beat slower than smaller ones. Your maximum heart rate can also be affected by certain drugs and antihistamines. When you keep your heart rate up, it strengthens your heart, so it's possible to improve your heart health using cardiovascular exercise. 

Ways To Measure Your MHR

While there are many formulas available to calculate your maximum heart rate, the formulas that have been studied the most are:

  • Fox formula (the most common formula for women and men): 220 - age
  • Gulati formula (only for women): 206 - (0.88 x age)
  • Hunt formula (for active women and men): 211 - (0.64 x age)
  • Tanaka formula (women and men over 40 years of age): 208 - (0.7 x age)

The most common formula for years was the fox formula, but as time went on, experts realized that this formula doesn't take into account the way the heart rate changes with age. As humans age, the maximum heart rate decreases naturally. The fox formula doesn't take into consideration that aging depresses the sinoatrial node, which is the natural pacemaker of the heart.  

Some of the formulas were also found to greatly overestimate the maximum heart rate for women, which can cause issues for women and in certain cases can be dangerous. Therefore, a female-specific formula was developed to be able to more accurately calculate a woman's maximum heart rate based on her age. If you don't want to calculate your maximum heart rate yourself, there are heart rate monitors you can use to track both your heart rate and maximum heart rate.

Is Everyone's MHR the Same?

Everyone's maximum heart rate is not the same, and so many different factors are taken into consideration when calculating it. Some of the things that affect maximum heart rate are: gender, age, fitness, genes, and a person's size. A young woman athlete is going to have a very different maximum heart rate than a young man that doesn't exercise regularly. It's important to have an accurate calculation of your maximum heart rate so you can exercise at your peak performance and get the most out of your workouts. 

When you know your maximum heart rate, you can push yourself to work as hard as you physically can, but it's also important to remember that you can't sustain this maximum effort for extended periods of time. If you exercise above your personal anaerobic threshold, your body can produce excess amounts of lactic acid, which can lead to post-exercise muscle soreness. To get the best results from your workouts, it's best to alternate workouts between different heart rate zones.