Does Heart Rate Really Matter?

by Jessica Remitz

You may have heard personal trainers and doctors stress the importance of heart rate without ever really answering a simple question: why does it matter? And how should heart rate be measured? We’ve asked an expert to explain why measuring heart rate during exercise is important and how to use it to get the most out of your workout.

Why Measure Heart Rate?

There are a number of reasons why measuring heart rate can help make workouts more effective. Measuring heart rate gives us feedback on our current health status and the recovery time we need, said Lesley Mettler, founder and owner of CoachLesley.com and a premiere triathlete coach in Washington. It also gives us more information about the intensity we’re working at and can help you to compare data between similar training sessions to see what changes have occurred and how your body is responding to certain intensity levels. Mettler also recommends monitoring heart rate to:

• Prevent yourself from working too hard or too fast for too many days in a row, which can lead to injury or burn out.
• Monitor weight loss, endurance training, and cholesterol levels by teaching the body to use fat as a fuel source and stay between certain heart rate ranges.
• Encourage cardiovascular training by keeping heart rate aerobic versus anaerobic.

How to Measure Heart Rate?

Measuring your heart rate can seem tricky without a machine or gadget to do it for you, but it only takes about 30 seconds and two fingers. Start by taking your pulse with your index and middle finger placed on your neck or wrist. Count the number of beats for six seconds then add a zero, or count the number of beats for 30 seconds and double that amount.  Ideal heart rate ranges vary depending on your age and fitness level, but you can use a rudimentary equation of 220 – age = maximum heart rate to create “easy,” “moderate,” and “difficult” zones from there. Mettler recommends this equation for beginner exercisers or those with less-than-average fitness levels but warns that it may be inaccurate for more regular exercisers. She also recommends using the Karvonen formula, which uses your resting heart rate to determine a range for training. Some equipment at your gym may have sensors, but Mettler doesn’t find them to be all that accurate. Your best bet? Use those numbers as a guide and think about if it makes sense against the intensity at which you’re exercising.

“You always need to take into account your Rate of Perceived Exertion (RPE), that internal question of, ‘How hard do I think I am working?'” she said, “because formulas can be off, your RPE along with the formula can give you the best idea of the range you want to be in when exercising.”

Heart Rate Tools and Tips

Exercising with the proper intensity level will help improve your overall fitness and, as a result, boost your fat burning ability and heart health, Mettler said. Once you’ve determined your ideal heart rate zones, Mettler recommends interval training to increase the intensity of your workouts while maintaining easy warm ups and rests throughout. Here are her fitness tips and favorite tools to measure heart rate:

• Use a five point system to determine where you are in terms of RPE then match it to your heart rate numbers. The five points throughout your workout should be “very easy,” “easy,” “moderate,” “top moderate,” and “hard.” At the first level, you should be able to have a full conversation. At the top level, you should be unable to talk.
• For a 45 minute workout, begin with a “very easy” to “easy” warm-up for 10 to 15 minutes then, depending on your fitness level, do 10 to 20 minutes of short intervals with 15 to 45 seconds of “moderate” to “hard” exercise with “easy” rest in between. Finish with an “easy” 10-minute cool down. This routine can be done on an elliptical trainer, bike or running.
• Trigger your intensity levels with a trail run, short hill repeats or stair running, which can be a great way to add intensity if you don’t have access to hills.
• Remember that heart rate is just one tool at your disposal and can be affected by heat, dehydration, altitude, lack of sleep, caffeine and pain. Learn to listen to how you feel.
• Retest yourself often. As your fitness level improves, your heart rate ranges will continue to get better.
• Try investing in a watch to help monitor your heart rate during exercise. Mettler says Polar or Garmin brands are her favorite.