Doing the Math for Fat Burning

Let's talk about weight loss.

For weight loss, the American College of Sports Medicine (ACSM) recommends maintaining a heart rate of 70-75 percent of the maximum heart rate for 45 minutes a day.

That's great, but how do we determine that heart rate range? How do we know what 100 percent of our max heart rate is?

The good news is you don't have to know these things. Just use the Karvonen Formula.

The Karvonen Formula for 70 percent of your max heart rate:
Start with 220
Subtract your age
Subtract your resting heart rate
Then multiply this by .70 (which is 70 percent)
Then add back in your resting heart rate.

Let's do mine for practice. I am 47 years old and my resting heart rate is 68.

For me, the formula looks like this (for 70 percent):
220-47=173
173-68= 105
105 x .70=73.5
73.5+68= 141.5

for 75 percent:
220-47=173
173-68= 105
105 x .75=78.7
78.7+68=146.7

My target heart rate is 141.5-146.7 for 45 minutes for weight loss.

For Chris, who is 43 with a resting heart rate of 60:
220-43= 177
177-60=117
103 x .75=87.7
87.7+60=147.7

220-43= 177
177-60=117
103 x .70=81.9
81.9+60=141.9

Chris' is 141.9-147.7 for 45 minutes for weight loss.

Go ahead -- do yours!