So, you’re ready to use a heart rate monitor—but how do you find your zones?

The Karvonen Formula is one of the most effective ways to determine training zones because it takes the resting heart rate into account, which is a good indicator of fitness levels. To find your heart rate training zones, follow the procedure below.

1. Find your average Resting Heart Rate (RHR) by taking your heart rate first thing in the morning (before even getting out of bed) for at least 3 days in a row. Place a heart rate monitor on your bedside table or use the tried and true method of taking your pulse for an entire minute. Take the average of three days to determine your RHR.

2. Find your Maximum Heart Rate (MHR) by using one of the following methods:

• Age Predicted Max Heart Rate: Use the standard formula of 220 minus your age (which only holds true for a small part of the population.)
• 5 Kilometer Race Test: Enter a 5K race (cross-country ski, snowshoe, bike, run, whatever) and during the last 1-2 minutes, go to a full sprint. Add 5 beats to the highest number recorded during this period to estimate your MHR (because of muscle fatigue, you cannot drive yourself all the way to true max.)
• The Two-to-Four-Minute Test: Perform this test with a partner. Warm up for at least 15 minutes. Gradually increase speed and resistance so that HR increases by 5 beats every 15 seconds. At each 15-second interval, your partner shouts your exercise time and HR. Keep going until, even with increased effort, your HR no longer increases. At this point, your breathing is labored and difficult. Remember, Max HR is very uncomfortable! It should take you 2-4 minutes if your partner has helped you set the pace correctly.
• Biggest Number Test: If you have been wearing a heart rate monitor for a while, go with the biggest number you have ever seen on the monitor.
• Talk Test: Exercise until you find talking uncomfortable. Add 30-40 beats as a “guesstimate” of MHR.

3. Determine your Heart Rate Reserve (HRR) by subtracting your RHR from MHR:

  MHR – RHR = HRR

4. Transfer the HRR you just calculated into the HRR column below, multiply it by the listed percentages and then add your RHR back into the second column.

ZONE	HRR	xINTENSITY	+RHR	= TRAINING HEART RATE
55%		X .55
60%		X .60
65%		X .65
70%		X .70
75%		X .75
80%		X .80
85%		X .85
90%		X .90

 

Remember, if you want to exercise at a moderate intensity level, you will spend most of your time in the 65-80% range.