How important is using a heart rate monitor when exercising?

One of the reasons so many Americans are overweight is because they aren't training in the right heart rate zone. We have been taught to exercise at a fixed or target heart rate. But it doesn't work for most people, so they are getting less fit and more fat every year. People need to learn a new way of working out by wearing a heart-rate monitor (HRM) and training within multiple zones.

Fat is burned in all the heart rate zones; it's the burn rate that's the key factor. A heart rate monitor serves as a guide to make sure you train according to the demands of your workout in conjunction with your target heart rate. Besides, an HRM is more accurate than taking your pulse from your neck or wrist.

If you are just beginning to train, use a heart rate monitor to be sure that you are not overtraining. Your HRM can keep you at 60 to 70 percent of your maximum heart rate so you don't overdo it. After a few months of training, your HRM may reward you by sending you the message that your resting heart rate has dropped several beats per minute.

Most experts agree that, in order to get the maximum benefits from aerobic exercise, you will want to vary your routines so that you remain challenged. A heart rate monitor can then help you to track the intensity of your effort to make sure you stay within certain heart rate parameters.

Of course you can do a ten second count while taking your pulse (wrist pulses are usually the best area to use) however, doing this repeatedly, especially when you are sweating and trying to put in a good effort can be a bit cumbersome and annoying. You can invest in a heart rate monitor, which typically has 2 components—a strap to put around your chest under your shirt, and a wrist component that looks like a watch. These models give you constant readings that are easy to see. More expensive models may also offer features like a pedometer, stopwatch, heart recovery measurements, beeping alarm when you go above a certain heart rate, backlight for visibility.

Chemicals just can’t move between blood and muscle, or within the muscle, fast enough to keep up with the demand at a heart rate of around 80 percent of maximum. For the fifty-year-old, that’s a heart rate of 136 per minute; at sixty-five, it’s 124. If you go above your number, your muscles become starved of oxygen and the glucose can’t burn all the way down to carbon dioxide. Instead, you build up a sludge called lactate, which is incompletely burned sugar and which shuts down your muscle function after a few seconds of exercise at peak levels (like sprinting the length of a football field). As with the switch from fat to glucose, the switch into “anaerobic” metabolism, where there isn’t enough oxygen, has ripple effects throughout your body.

The only way to tell when you reach and cross these thresholds is with a heart rate monitor. You can’t do it by how you feel. Even Olympic athletes, training six hours a day for years, can’t do it by how they feel. You can certainly get in shape without a heart rate monitor, but you’ll waste a fair amount of your time and effort.

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Using a heart rate monitor during your exercise sessions is important so that you are able to work at the most efficient level for your body. Some exercisers may discover that they are indeed working harder than they need to be or not hard enough and can then adjust their exercise routine based on the heart rate feedback. As your fitness level improves, your heart rate will drop more quickly after a workout. An ideal decrease is 20 beats in the first minute. You can check this by taking your heart rate immediately post workout and then one minute later. With time, your heart rate monitor will quickly become essential in guiding the intensity of your exercise sessions.

If you have been working out for a some time, then more than likely you have created a good cardiovascular base for yourself. A heart rate monitor will help take your program to the next level. The most important part of any fitness program is getting feedback on your progress. This feedback is used to help you adjust your workout program so you keep progressing (weight loss or improved cardiovascular condition) and ensuring you don’t hit a plateau. A heart rate monitor is one way to get this type of feedback. The problem is that the formulas that most people are introduced to don’t work for everyone. This means that a formula may have you training too hard or not hard enough. If you are using a heart monitor, you will need to do one of two things.

  1. Get a VO2 assessment done at a local fitness center. This assessment determines your heart rate zones based on your fitness level and genetics, not just age which most formulas use.
  2. If you are not able to do a VO2 test, use the most basic heart rate formula, 220-age. This formula is very conservative and will help you get started. Use 65 percent (for low) and 80 percent (for high) of 220-age to begin, then make adjustments in the zones based on how you feel. Once you have found your personal heart rate zones, using a heart rate monitor becomes very useful to help you determine and achieve the intensity you want in each workout.
Jonathan Penney
Fitness Specialist

Heart rate monitors are great tools to have and to use. If you are able to check your heart rate then you can simply do that periodically throughout your workout. However, if you are using a heart rate monitor to stay within a certain zone—i.e. 60 to 65 percent of your max heart rate—then having a monitor would make life much easier than having to check your pulse. The choice is truly yours, but it never hurts to have one present.

Using a heart rate monitor is a good way to give you visual feedback of where your heart rate is. It's easy to overestimate or underestimate sometimes, especially if you are just starting out, so a HRM can be a very helpful tool.

I like the HRM's that display calories burned (not all of them have this feature). Even though it's just an estimate, it helps give you an idea of where you are. Sometimes it helps push you to workout harder or a little longer. For example, if your goal is to burn 400 calories, and you have your HRM on, you can see approximately how long it will take you to get to your goal of 400 calories.

You can use your heart rate for a more efficient workout by using cardio zone heart rate training guides to tailor each exercise with your goals. For example, as you may have seen on a treadmill or elliptical machine, optimal heart rates are based on age and a graph can be used to target your training zone. Lower exercise heart rates target fat burning, more elevated heart rates target cardio training and endurance and even higher heart rates may be potentially dangerous.

Luis Alonso, NASM Elite Trainer
Fitness Specialist

I perform quite a bit of metabolic testing and I know the difference using one of these devices can make in your exercise program. Take it from me, if you don’t use a heart rate monitor, then you might not be getting the most out of your workouts. It is one of the first things that I have my clients invest in that I’m usually thanked for later! As long as you’re taking the time to exercise, you might as well stop guessing what your heart rate is and start getting acquainted with a machine whose sole purpose for existing is to help you reach your goals. It is simply one of the best tools to help keep you accountable for training at the intensities that are right for you.

A heart rate monitor is like having a speedometer for your heart on your wrist. It is a device that is worn like a watch and, when coupled with the transmitter, which is a light, thin strap typically worn around your chest, it can provide you with your heart rate, at any given time, during any given activity. When you program it with your vital statistics such as your age, height, weight and gender, it will also calculate the amount of calories you are expending throughout your day, as well as track calorie expenditure during your workouts. Depending on the sophistication of the model, a heart rate monitor can also provide you with personalized heart rate zones; time spent in each zone, target zone alarms, lap counters and a plethora of other information which can be stored in its memory.

On some models, it’s even possible to download the stored data to a laptop computer for tracking progress over time and further analysis. There’s nothing like seeing the proof of your accountability in the form of a graph on your computer screen that shows how your heart rate and calorie expenditure have improved over time and the gratification that you feel when you look in the mirror confirming the fact. All heart rate monitors today can last for years and require very little maintenance. They are simple to use and water-resistant, too.

Also, there is a heart rate monitor to meet almost any budget, and the information about your workouts that they provide can be useful enough to far outweigh the initial cost. It’s one of the best investments you can make for yourself. For more information about heart rate monitors, visit the consumer site for a company called Polar, at They were first in patenting the technology and are still a leader in the field. Good luck!

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.