You Gotta Have Heart

A heart rate monitor is to a TOJ what a telescope was to Galileo. It provides another insight beyond speed, reps, weight, or distance to measure exercise intensity.

While elite athletes use heart rate monitors as a precision instrument with which to train their bodies the the their max, this TOJ uses one because it is fun to explore how heart rate correlates to the spectrum of sensations experienced between exertion and exhaustion during intense or prolonged exercise.

I've made some interesting discoveries with my Polar heart rate monitor. I was surprised to find that when trudging up a mountainside my heart rate rises, but rarely gets as high has it does on the flats. Even more surprising was the tremendous drop in heart rate coming down. Though my thighs throb, my heart rate drops into a zone where it's not clear there's much training effect, at least according to the conventional calculations for the so-called aerobic zone. My heart also beats slightly harder on a bicycle going uphill than when I run.

Whenever I do intervals where my heart beats close to its maximum rate, I watch to see if it drops a minimum of 30 beats within a minute after completion of the interval. That's a reliable indicator of a good fitness level, and when it doesn't drop that fast after an interval, I'm nearing exhaustion. Sometimes when I workout hard several days in a row, I leave the monitor on after the workout to see how long it takes for my resting rate to return close to normal. If it doesn't return to normal within an hour or so, from my experience, that means I've not recovering between workouts, and that can lead to inflammation and a weakened immune system, making me more susceptible to colds and flu.

Typically heart rate monitors are used to determine some number, based on age, close to maximum heart rate and then the aerobic and fat-burning range between 65% and 80% of maximum heart rate. Truth be told, determining optimum aerobic zones is an inexact science.

For years, dogma was that your maximum heart rate is 220 minus your age, but the calculation has become more elaborate than that. In fact, it's difficult to determine exactly what your max heart rate is, although if you sprint to the point of exhaustion and capture the highest value on your heart rate monitor, you'll be close enough. (Note: Make sure your doctor has cleared you to exercise at that level of intensity, especially if you're a TOJ.)

Online you'll find a plethora of heart rate/aerobic zone calculators. One included a factor that differentiated between the rates for men and women. Here are three good examples: the Mayo Clinic, a fitness site, and a gear (like heart rate monitors) site. I found the gear site correlated the best with mine. Yours may be different.

Using a heart rate monitor during any kind of exercise will make you think about all kinds of things. Recently the NY Times had a good article that raised questions about whether it's best to train in the morning or in the afternoon. The author had discovered a pattern: according to her heart rate monitor, her heart rated tended to be lower in the morning and higher in the afternoon when doing the identical exercise. Some chrono-biologists chimed in that the body may be more primed for hard exercise in the afternoon.

By itself, heart rate is not very useful because it is affected by age, temperature and humidity, how rested your muscles are, what you've been eating, among many other factors. But I've found if you frequently wear one, you develop a sense of how all these are related and reflected in that number. WebMD has an informative summary of the myths and facts regarding heart rate, including the fact that your maximum heart rate declines 7 beats per decade of life. If you really want to learn a lot about it, check out Joe Friel's Total Heart Rate Training.

If you've been a good TOJ this year, ask Santa for one. It's a perfect recession gift -- good for your health and cheaper than a new pair of running shoes.

Merry Christmas!

No comments: