By Carolyn Richardson and Mary Hartley, RD

If you are curious about how you can exercise more efficiently and get the best results, a heart-rate monitor may help.  But if RHR, MHR and THR don’t sound familiar, chances are you have some learning to do before buying one.  While professional athletes and heart disease patients are familiar with heart rate monitors, you may benefit from using one too.

We have heard the basic tenets of a good workout: warm-up, moderate to high intensity activity, cool down, and stretch.  This guideline is based on training your body to perform at its best. By monitoring your heart rate during a workout, you can avoid both overexertion and under-performance.  Here’s how to train in the zone.

RMR, MHR and THR

The way to maximize the benefits of a heart-rate monitor is to know your Resting Heart Rate (RHR), Maximum Heart Rate (MHR) and Target Heart Rate (THR).  Knowing these numbers can make it easier to reach your fitness goals.

• RHR is the number of heart beats in one minute when you are at complete rest.
• MHR is the fastest and hardest your heart can beat per minute during exercise
• THR is ideal level heart rate for exercise training where your heart is being exercised but not overworked.  THR is 60-90% of MHR.  The exact number to aim for depends on your training goals.

The Guide to Exercise at About.com explains how to calculate your heart rate using those numbers, and your gym membership may offer a fitness test that provides the information as well.  When you have a heart rate monitor, it does the calculations for you.

Fat-Burn vs. Cardio

Maybe you have seen heart-rate charts on elliptical trainers that display designated “zones” ranging from warm-up, to fat-burn, to cardio, to maximum.  These “zones” mirror the effort that your heart is making to sustain your physical activity.  They are the percentage points from 60 to 90 within your Target Heart Rate zone.

Within the same amount of time, a low intensity workout in the 60 to 70 percent range burns more fat and fewer calories than a moderate intensity workout in the 70 to 80 of THR percent range.  In the low intensity “fat-burn zone” you burn mainly fat for fuel, but in the moderate intensity “cardio zone”, more glucose is burned along with fat. Athletes trying to achieve “peak” performance train in the maximum range for designated time periods to push their performance goals.   In truth, you need different levels of intensity over a typical week of training, modified according to your own fitness level by using the heart rate monitor.  The Guide to Exercise at About.com provides several workout schedules based on your percent of THR zone.

Time to Buy?

The most basic heart rate monitors track heart rate only, while high-tech monitors track calorie output during exercise and give personal workout advice among other things.  Before you decide which one to buy, read this review of heart rate monitors at Consumer Search (disclaimer: owned by our parent company, About.com.)

Who needs a heart rate monitor and how they work has been hotly debated. Casual exercisers don’t need a heart rate monitor.  But if personal feedback motivates you, then a heart rate monitor may be the extra tool that helps you to get fit.  Just as a close friend can give you feedback, an accurate heart-rate monitor can do the same.

Your thoughts.....

Do you exercise with a heart rate monitor?  Do you recommend it?