Heart rate is a measure of how many times your heart beats per minute. During exercise your heart rate increases in proportion to the intensity of the activity being performed. The harder we exert ourselves, the more oxygen we need, and the faster the heart will beat–but only up to a point. At a certain level of exertion, your heart rate begins to plateau and will no longer increase no matter how much harder you exert yourself. This is called your maximum heart rate.
Unlike your resting heart rate, your maximum heart rate does not vary much with your level of fitness and is more dependent on age and genetics. Finding your maximum hear rate can be a useful tool for figuring out how hard you are exercising. Knowing the intensity of your workouts helps to effectively design and progress your exercise routine. It is also useful for ensuring that you’re working out hard enough to improve your cardiovascular fitness.
Maximum Heart Rate Calculation
Estimates of maximum heart rate can be made based on your age, since maximum heart rate shows a small but consistent decrease of about 1 beat per year beginning at around 15 years of age. The easiest and best known way to calculate your maximum heart rate is the following formula:
HRmax = 220 – Age
Based on this formula, a 30 year old would have a maximum heart rate of 190 beats per minute (bpm). Subtracting your age from 220 is a relatively simple method, but it only provides an estimate and individual values can vary widely from this average. In 2007, researchers developed a slightly more accurate formula, but one that’s a little more difficult to compute in your head.
HRmax = 206.9 – (0.67 × age)
So using this formula, a 30 year old individual would have a maximum heart rate of 186.8, pretty close to the value we got from the first equation. Again though, these are only rough guides to follow and don’t guarantee the number you calculate will be close to your individual maximum rate. Two athletes of the same age can likely have max heart rates that are 20 bpm apart from each other, and possibly as big a difference as 60 bpm.
Measuring Max Heart Rate During Exercise
It’s sometimes helpful to compare the estimated values from the calculations above with an actual heart rate value obtained from high intensity exercise. Cardiac stress testing is the most accurate way to arrive at your maximum heart rate, but it is also the most taxing and requires supervision from a medical professional to be done safely. Checking your heart rate after a hard bout of exercise probably will get you fairly close to your maximum, and can be used in comparison to see how accurate the calculations were. Before attempting any heart rate testing on your own, be sure to get clearance from your physician for high intensity exercise, or have the performance testing done at a medical center that offers the service.
Sub-maximal exercise testing can be done running on a treadmill, outside on a hill or track, or also by using cardio equipment like an elliptical machine or rower. It should be noted that your heart rate will be slightly different depending on what activity you are doing, because different exercises engage different muscles. A portable heart rate monitor can be used to make recording easier, but checking you pulse works well too. To manually check your heart rate, place your index and middle fingers on your wrist below the base of your thumb and count your pulse for 15 seconds, then multiply that number by four to get the number of beats per minute.
One method for exercise testing is as follows:
- Start with a 5-10 minute warm up at a comfortable pace.
- After the warm up, continue exercising but at an intensity level that causes your breathing to become heavy enough that it would be difficult to carry on a normal conversation. Try to keep up this pace for another 10 minutes.
- When those 10 minutes are up, immediately go into a full-out sprint for as long as you can maintain that pace (usually no more than 1-2 minutes). After the sprint, stop completely and record your heart rate.
Values recorded using this method usually fall just short of the maximum, so adding 5 or 10 bpm to whatever number you get may give a better estimate.
How to Use Max Heart Rate
One of the most common uses for maximum heart rate is to set training zones of intensity. For example, the American College of Sports Medicine recommends adults should get at least 150 minutes of moderate-intensity exercise per week. This equates to about 30 minutes of exercise, 5 days a week. The Centers for Disease Control says that for moderate-intensity a person’s target heart rate should be between 50% and 70% of their maximum heart rate. So once we have an estimate of what our maximum is, we can calculate percentages of that and work to keep our training within those set zones.