“If I walk 3.5 miles in an hour on the treadmill, is that fast enough?” I asked my doctor.
“That’s the wrong question,” he replied. “You need to know your heart rate. It needs to be working at 70 to 80 percent of its maximum.”
My doctor, David Tanner, is professionally a doctor of osteopathic medicine (D.O.) and personally an athlete. He was working on my neck, which was stiff from too many hours at my computer, when he suggested that I need a heart rate monitor for my exercise program.
I used to have a heart rate monitor made by Polar Electro. But eventually the battery died. I never replaced it and lost track of the monitor when I moved to Colorado.
That heart rate monitor cost me more than $100, so I was surprised that Dr. Tanner told me that I could buy a Polar heart rate monitor for under $30 now. I went right out to the chain store he recommended, Performance Bicyle, and bought the basic Polar B1 model for $29.97 plus sales tax.
My doctor and I agree that Polar makes the most reliable heart rate monitors. A professor of electronics at Oulu University in Finland named Seppo Säynäjäkangas in 1982 patented the first portable heart rate monitor, and today the company that he founded is still the leading manufacturer of heart rate monitors.
When you use a heart rate monitor, the first step is to calculate your maximum heart rate. This is the fastest that your heart can beat for one minute.
The easiest calculation is to subtract your age from 220. Then, multiply the result by 0.7 and then by 0.8 to find out what 70 percent and 80 percent of your maximum heart rate is.
The other common way to calculate your maximum heart rate is the Karvonen formula, which uses your age and your resting heart rate. Polar has a neat calculator on its website.
It turns out that the speed that I was walking on the treadmill was fast enough to give my heart a good work out. It was not too fast or too far either either. Dr. Tanner says that it’s too much when you doubt if you couldn’t go any faster or farther.
Everyone needs regular exercise, but people like me with type 2 diabetes have to take special care of our bodies. Exercise, eating less, and medication are the three keys to increasing insulin sensitivity, which is the problem for most people with diabetes. And for most folks, exercise is probably easier than eating less and has fewer side effects than any pill.
I wear my new heart rate monitor whether I walk on the treadmill or the trails around here. With it I’m confident that the exercise I’m getting is the right intensity for my heart.
This article is based on an earlier version of my article published by HealthCentral.