Training With A Heart Rate Monitor

Submitted by Rickshaw :: Wed Dec 29, 2004 9:56 am

With basic heart rate monitors like the Polar F1 now selling for under $50, they've become a popular training tool for runners. But while the devices make it simple to measure your heart rate, it's not always clear how to use that information to help guide your training. Some of the biggest names in coaching even recommend against HRM-based training. So are these monitors really worth the trouble? How can they be used most effectively?

Measuring your max: Because normal heart rate values vary from person to person, you'll need to know your maximum heart rate before you can get much benefit from any HRM. Workout intensities can then be expressed as a percentage of max HR, rather than as a specific HR value. A rough formula for approximating your max HR is 220 minus your age, but there's enough variability among people that it’s better to do an actual performance test. Most HRMs and training books contain instructions for a high-intensity workout designed to push your HR as high as it will go. This is the only reliable way to determine your max HR.

Setting the pace: Once you know your max, you can use it to determine appropriate ranges for various types of workouts. Here are the HR ranges recommended by Pete Pfitzinger and Jack Daniels, two well-known running coaches:

VO2max intervals: Pfitzinger 94-98% of max, Daniels 98-100%
Lactate threshold runs: Pfitzinger 80-90%, Daniels 90%
Easy/Long runs: Pfitzinger 73-83%, Daniels 70-75%

These ranges are a general guide, but it can be dangerous to rely on them too literally. A wide array of factors can affect your HR on a given day: temperature, wind, altitude, illness, hydration, and even whether you're indoors or outdoors. Additionally, your HR will drift several beats per minute higher during the course of a long run at a steady pace. All these variables can make it difficult to interpret HR results with any accuracy, which is why Daniels in particular advises against HR-based training in most circumstances.

Putting it to use: So when is a HRM useful? As long its limitations are taken into account, it can still be helpful for setting appropriate training paces, especially for beginners who lack a feel for the right pace. It can also checkpoint your current fitness. If you run the same workout at the same pace every few weeks, and observe your average HR for the workout decreasing from week to week, then you'll know you're improving.

Another good use of a HRM is for judging recovery periods during interval training. Rather than waiting a fixed amount of time between intervals, you might instead wait until your HR drops below a particular level.

Resting HR: Measuring your resting heart rate can also provide you with valuable information. RHR is best measured first thing in the morning, immediately after you wake up. When measured regularly, a slower RHR can indicate increasing fitness. An abnormally high RHR can be a sign of overtraining or illness.

HRMs and racing: Most coaches do not recommend the use of a HRM during races as a way to keep pace. Thanks to the excitement and adrenaline of race day, your HR may be elevated due to reasons other than physical exertion. However, measuring your HR during a race and reviewing the data afterwards can be a good way to gain insight into the race, and prepare better for the next one.

If you'd like to learn more about HRM-based training, there's a wealth of detailed programs and advice to be found on the internet. There are also a number of books devoted to HRM-based training, such as Heart Monitor Training for the Compleat Idiot, by the popular author John L. Parker.