The target heart rate represents the intensity level at which you should exercise to produce cardiorespiratory benefits. This amount of exercise (overload) is enough to condition the heart, lungs, and muscles but is not overly strenuous. Monitoring intensity during a workout is done by measuring the heart rate. For fitness to occur, your heart rate must be raised to approximately 60 percent of the difference between the resting and maximal heart rates. The difference is called the heart rate reserve (HRR). An increase in heart rate equal to 80 percent of the difference between resting and maximal rates (i.e., HRR) is a reasonable upper intensity level for most exercises. This is the target heart rate range (or training heart rate range). The Karvonen formula for calculating your target heart rate is as follows:

THR = (maximal HR* - resting HR**) Intensity % + Resting HR

*Maximal HRmax = 220 minus age **Resting HR = count your pulse at rest for 60 seconds

When estimating your target heart rate range, two factors are involved:

Your age:

Your resting heart rate (RHR):

Use these numbers in the formula that follows:

1.

220

-

_

=

0

your age

(estimated maximal heart rate [MHR])

2.

0

-

_

=

0

MHR

(resting HR)

HR reserve

3.

0

X

.60

+

_

=

0

(HR reserve)

(lower intensity)

(resting HR)

(lower target heart rate)

0

X

.80

+

_

=

0

(HR reserve)

(higher intensity)

(resting HR)

(higher target heart rate)

4.

Target heart rate range is

0

to

0

beats per minute.

5.

For a quick pulse check during exercise, my THR 10 is

0

to

0

beats.

Example: Jeff is 23 years old and has a resting heart rate of 72 beats per minute.
1.	220 - 23 = 197 MHR (estimated)
2.	197 - 72 = 125 heart rate reserve
3.	125 .60 = 75 + 72 = 147
	125 .80 = 100 + 72 = 172
4.	THR range is 147 to 172 beats per minute.
5.	THR 10 is 15 to 17 beats.