karvonen formula

Amarillo_NDN

This method of calculating your target training zone is based on your maximal heartrate and resting pulse.
The correlation here is more directly linear: 60% to 80% of your Heart Rate Reserve, HRR, equals 60% to 80% of your functional capacity.

To determine your target training zone with HRR, do this:

Take your resting pulse three mornings in a row, just after waking up. Add all of them together, and divide by 3, to get the average.

Let's say your average is 60 beats per minute.

(220) - (your age) = MaxHR

(MaxHR) - (resting heart rate) = HRR

(HRR) x (60% to 80%) = training range %

(training range %) + (resting heart rate) = (your target training zone)

so,

220 - 35 = 185 (MaxHR)

185 - 60 = 125 (HRR)

125 x .6 = 75 (60% training percentage)

125 x .8 = 100 (80% training percentage)

75 + 60 = 135 (target training zone, in beats per minute)
100 + 60 = 160 (target training zone, in beats per minute)

So, your target training zone, in beats per minute is 135 to 160. Of course, to get a 15 second target simply divide each number by 4. That would be 34 to 40 beats over 15 seconds. When counting beats, start with the first beat as zero: ie. 0-1-2-3-4...38-39-40.