How to Use Your Heart Rate Monitor

Your heart is the most important muscle in your body, and most of us are aware of the importance of getting enough cardiovascular exercise. Using a heart rate monitor can help assure that you are working your heart properly as you exercise. Like any muscle, the heart needs to be exercised, and serves as a barometer for the rest of your body by telling you how hard you are loading it during various functions. It circulates blood, rich in oxygen from breathing, from your lungs to your trunk and lower extremities. Monitoring your heart rate is the easiest way to keep yourself working in the right "zone," reducing your chance of injury and overtraining, and increasing the odds that you'll get the results you want.

Heart rate monitors can measure your cardiovascular and physiological stress during training sessions. They provide you with an accurate gauge of the intensity of an exercise, which is reflected in your heart rate. The harder you exercise, the higher the heart rate should go. When your heart rate changes, it's a sign that something is happening, which can be something good or something bad. In either case, having this information will allow you to properly react. By constantly monitoring your heart rate, you will learn to tell when your workouts are effective, when you are over or undertraining, and even when you may be getting sick and need to back off.

The Basics
Heart rates are measured in beats per minute (bpm). Your resting heart rate indicates your basic fitness level and is defined by the number of times your heart beats per minute while your body is at rest. The more well conditioned your body, the less effort and fewer beats per minute it takes your heart to pump blood to your body at rest. Measure your resting heart rate immediately after awakening and before you get out of bed. Take these measurements for five consecutive days and find the average. This average is your actual resting heart rate. Resting heart rate is dependent on your living habits and a number of factors such as quality of sleep, stress level, and eating habits.

Your average heart rate is the number of times it beats in a certain period, like over the course of a workout.

Your maximum heart rate (Max HR) is the highest number of times your heart can contract in one minute. Max HR is the most useful tool to be used in determining training intensities, because it can be individually measured and predicted. Unfortunately, the only way to get a true accurate reading is to have an exercise test clinically administered. Without this option, you are forced to use a ballpark figure, which can be calculated using this formula:

Women: 226 - your age = your age-adjusted Max HR
Men: 220 - your age = your age-adjusted Max HR

For example, if you are a 30-year-old woman, your age-adjusted maximum heart rate is 226 - 30 years = 196 bpm (beats per minute). Keep in mind that these formulas apply only to adults and are not accurate. The generally accepted error in age-predicted formulas is +/-10 to 15 beats per minute, which is due to different inherited characteristics and exercise training. If you want to exercise/train at your most effective levels, your Max HR should be measured, but this formula will work fine for your immediate purposes, and self-knowledge will allow you to make the necessary adjustments.

Your anaerobic threshold is the physiological point during exercise at which muscles start using up more oxygen than the body can transport (the point where lactic acid accumulates and you get "pumped"). It's also worth noting that while you can train your max heart rate and your anaerobic threshold (so that they are always changing slightly), the actual numbers don't correspond to fitness versus another individual. Some people have naturally higher maximum heart rates than others.

A target zone is a heart rate range that guides your workout by keeping your intensity level between an upper and lower heart rate limit. There are various target zones that are suggested for an individual to follow that correspond with a specific exercise.

The Fat-Burning Zone. You'll notice the lack of something called the fat-burning zone in the table below. The reason for this is that it's misleading because people feel the need to stay in this low heart rate zone in order to burn fat. This is not even close to being true. This misnomer is based on your body being able to use a higher percentage of fat for fuel at low outputs. It is true, however, that your body will lose far more fat at higher outputs (more on this below).

In the lower zones, or cruise zones as they are sometimes called, you can train for longer periods of time. But, as you move up to higher-intensity zones, you need to decrease the amount of time that you spend there, particularly in the top two (the Threshold and Redline Zones). To put it simply: you can walk farther than you can sprint, and overdoing it is nearly a guarantee of injuries or burnout.

Zones are relative. Your five heart rate zones are specific to your maximum heart rate, not anybody else's. With two runners, each maintaining a heart rate of 160 bpm, one might well be in their Z4 Threshold Zone and the other may be in their Z2 Temperate Zone.

Each heart zone burns a different number of calories per minute based on how fit you are:

Zone 1 = 3-7 calories per minute
Zone 2 = 7-12 calories per minute
Zone 3 = 12-17 calories per minute
Zone 4 = 17-20 calories per minute
Zone 5 = 20+ calories per minute

Fat is burned differently in each of the heart zones. You'll burn a different ratio of fat to carbohydrates in each of the heart zones. And once you've crossed over the exercise intensity threshold called the "anaerobic threshold," you are burning no additional fat, though you still burn fat. That's because oxygen has to be present for fat to burn. If there's no additional oxygen present, there's no additional fat burned during this period. However, don't confuse this with meaning that you won't lose body fat in higher zones. Another factor that results from training in these zones is a reduction in body fat, such as an elevated metabolism over time caused by muscular breakdown and/or increased muscle mass, which raises the metabolism.

Because of the example cited above, you want to do each workout to the maximum of your ability. This means that you don't back off so that your heart rate falls into a lower zone on purpose. The only exception is in our rare "doubles" routines, where one of your two workouts is supposed to be at "low to moderate intensity," meaning that you don't want to exceed Z2. But our programs are based on efficiency, and in most cases, intensity = efficiency. Heart rate zones are used to base training on when volume becomes a consideration. Remember, the higher the intensity, then less time you need to spend. Low-intensity outputs are important to train for high-duration activity and for recovery.

For many people who are not "hardcore" fitness enthusiasts, the concept of intensity to get results might not be clear. Your heart rate monitor will be a great tool to help you follow along and track your progress, and make sure you are working hard enough to get the cardiovascular and fat-burning results you want.

In general, you should see a pattern throughout the course of each workout. Most of us will find that our max heart rate and average heart rate will be higher in the workout at first. As you get into better shape and your neuromuscular coordination becomes more in tune with resistance training, this should change. You will be able to push harder while weight training and your cardiovascular shape will improve. Soon your max heart rate will be higher on the Sculpt days. If this isn't happening, then you probably aren't using enough weight. Your average heart rate overall should go slightly down the longer you do Sweat tapes and slightly up on Sculpt tapes. Besides what you see in the mirror, this is best way to see if you're making improvements in your health and fitness.

You will also learn that by tracking your progress, you'll be more in tune with external factors that are upsetting you. You will be able to tell when you are getting sick or overtraining by one of two ways. Either you won't be able to get your heart rate to maximums that you've seen prior, or your heart rate at rest will be too high. This is an indicator that something isn't quite right.

The best way to stay ahead of the game is by getting into the habit of checking your resting heart rate each morning before you get out of bed. As you get into shape, it should continually drop. If it reverses this pattern for more than a couple of days in a row, it's telling you that your body is stressed, which could be due to overtraining, the onset of an illness, or some other negative environmental impact. In any case, it's time to back off until your resting heart rate goes back down. So once you learn your body's patterns, you'll be able to anticipate your body's needs rather than just reacting to them.