Heart Rate Monitors

Wearing one won’t help unless you abide by what it tells you

Everyone reaches a point in their training and racing where they plateau. No
matter what you seem to do, you’ve leveled off. You’ve changed intensity or
varied the length of your long runs. You’ve added weight training to your regiment or perhaps you’ve incorporated aerobic cross training activities to provide active rest and variety. You’ve even tried stretching. Still no improvement. Could it be you’re getting older? No, that can’t be it. What’s to be done?

In any exercise program, there are four factors a person can "manipulate" to try to bring about change: frequency, duration, intensity and progression.

Frequency is the number of days per week you exercise. Frequency equals consistency.

Duration is the length of time you exercise. For runners, this can be measured in minutes or miles.

Progression means starting slowly and building gradually — trying not to add more than 10 percent to your weekly exercise program, in either time or distance.

Intensity means the level at which you exercise. How hard is the workout? At what pace are you doing your long, slow, steady runs? How fast are your intervals?

The one factor that is common to all aerobic activities is heart rate.

Heart rate is a barometer a professional athlete or weekend warrior can use to measure exercise intensity. Whether you run, swim, cycle or do aerobic dance, your heart rate during exercise (training heart rate) can tell you if you’re pushing too hard or not hard enough.

It’s simple: you can take your pulse for 10 seconds immediately after you stop exercising and multiply it by six to get your heart rate in beats per minute. The problem is that it takes time to find your pulse, and pulse is not always counted accurately. (Have you ever tried to take your pulse when your heart is racing along at 160 to 170 beats per minute?)

Also, after exercise is stopped, your heart immediately begins to recover to a resting level, the pulse you find and count won’t accurately reflect what your heart rate was during actual exercise.

Heart rate can be determined most accurately by using a heart rate monitor.

A heart rate monitor is a wireless, two-piece device consisting of a transmitter (worn around your chest) and a receiver (generally worn as a wrist watch). Electrodes in the transmitter pick up your heart rate and transmit the signal to the wrist receiver for an ongoing display of heart rate during rest or exercise.

The heart rate monitor can provide you with ongoing feedback from each exercise session. It allows you to train smarter — not necessarily faster.

You first need to determine your maximum heart rate or the maximum number of beats per minute that your heart is capable of beating. This can be estimated by taking 220 and subtracting your age. For a 40-year-old, for example, the maximum heart rate would be 180 beats per minute.

Remember, this is an estimate and the only way to accurately determine an individual’s true maximum heart rate is through scientific testing: running an individual to his maximum limits on a treadmill or track can determine "true" maximum heart rates. These evaluations should be performed under qualified supervision (physician, exercise physiologist, coach) as they require maximal effort. These "true" maximum heart rates can vary as much as 15 beats per minute from the "estimated" values, and that can make a difference when you try to determine your training heart rate range.

Once you’ve figured your maximum heart rate — true or estimated — you can calculate target heart rate ranges for different levels of exercise.

For an individual just starting an exercise program or coming back to one after a long layoff or injury, 50 percent to 60 percent of the maximum heart rate is an appropriate starting intensity. If, for example, your maximum heart rate is 180, 50 percent of your maximum is 90 beats per minute and 60 percent equals 108 beats per minute.

During the initial stages of training, to gradually adapt to the new level of activity, you’d want to exercise at a level that allows you to maintain a heart rate between 90 and 108 beats per minute for the duration of the workout.

If your heart rate goes above 108, slow down; less than 90, speed up. Your target heart range should be 90 to 108 beats per minute, whether the activity lasts 10 minutes or an hour.

By staying within this range, you’ll reap the maximum cardiovascular benefit.

For distance training, a target heart rate range between 60 percent and 80 percent of your maximum heart rate should be maintained. If your maximum heart rate is 180, your target heart rate range is 108 to 144 beats per minute.

So, when you heard out the door for a 12-miler on Sunday, you should try to keep your heart rate in this range. That way you’ll know you’re exercising aerobically, using oxygen as your main energy source and fat as your primary fuel.

Interval training requires a different level of intensity. It requires you to focus on increasing your anaerobic threshold so you can run faster for a longer period of time, so it necessitates an increase in training intensity.

If your maximum heart rate is 180 beats per minute, your target heart rate range for interval work will range from 80 percent to 90 percent of your maximum heart rate, or 144 to 162 beats per minute. If you exceed 90 percent of your maximum heart rate, you’ll produce lactic acid faster than you can diffuse it. If you work out at less than 80 percent of your maximum heart rate, you’ll activate your aerobic system.

The harder you work without exceeding your target heart rate range, the more efficiently you’ll function. Recovery should allow your heart rate to lower to a rate of 80 percent or less of your maximum heart rate — 144 beats per minute in this case — before you start your next hard repeat.

For a heart monitor to work, it’s important that you pay attention to what it’s telling you.

The other essential: patience. Staying within your target heart rate range will help you realize maximum improvement — and improvement will translate to faster times on the race course.

By maintaining your heart rate within your target heart rate range, you’ll be able to adapt to the increasing demands of your workout sessions, increase your speed and the efficiency of your cardiovascular system. By listening to what your heart rate monitor tells you, you can evaluate the effectiveness of each training session. Training and your target heart rate range can be affected by temperature, altitude, fatigue, hydration or dehydration, illness and nutrition. Each of these factors can affect whether you are training smart to realize maximum benefits, or if you’re overtraining and becoming tired.

Be advised that there are different types and models of heart rate monitors. All come with instructions to help you get the most benefit. Some monitors will provide only a readout of heart rate, while others will double as a wrist watch, stop watch and have the ability to store data. Top-of-the-line heart rate monitors allow you to download workout data onto a home computer.

Transmitters come with adjustable chest straps and some transmitters can be fitted into special sports bras.

The batteries in the watches and transmitters are generally waterproof and can be worn in the rain or while swimming. You can buy special attachments for your watch/receiver that enable you to attach it to your bicycle or other indoor exercise equipment — that way, heart rate can be viewed head-on rather than having to glance down at your wrist.

Many software companies offer fitness programs that can be used with a PC that will allow you to interface the heart rate monitor via external modem with their program. Heart rate data can be entered manually as well. This software can help tailor a fitness program to your individual needs.

To get the most out of training with a heart rate monitor, you may want to check out these selections:

"The Heart Rate Monitor Book" by Sally Edwards, Fleet Feet Press, 1996.

"Training, Lactate, Pulse-Rate" by Peter G.J.M. Janssen, Polar Electro Oy, 1997.

"Serious Training for Serious Athletes" by Rob Sleamaker, Leisure Press, 1989.