My wife and I recently attended a lecture by a man who claims that we can improve our brains by following certain natural methods (exercise, nutrition, etc.). He said that if we exercise and get our heart rate up to 80% - 85% of our maximum rate, we will have an increased level of Human Growth Hormones, and the higher level of HGH will improve the functioning of our brains. He said it isn't necessary to sustain that rate; just get the HR up to that level and then walk to let the HR come down, and then repeat the sequence for 10-15 minutes per day. He said to use a HR monitor to monitor the HR. He didn't say this, but I would suggest that non-runners start out at 40-50% of max and then slowly (maybe 5% per week) increase the rate up to 80%. Of course they should get an ok from their doctor before trying to increase the amount of HGH in their system.
My wife thought she would like to try his suggestion, so we bought a Polar HR monitor. She is a good walker and shouldn't have a problem with 50% of max.
I tried the monitor on my run today. It was interesting to see my various heart rates throughout the morning and then during my run.
The speaker we listened to used the traditional formula 220 - age as the maximum. That value isn't quite accurate, but it is close enough for most of us, and it is an easy formula to use. For my age (71) here is a table of HR rate values and percentage of maximum.
During the first mile, my HR slowly climbed up to 70%, and it remained at 70% for the next mile and a quarter when I reached my turn around. On the way back, my HR was at 71% until the last half mile where it was at 73%. I ran a little bit faster on the way back.
I was running at my comfortable speed, and the HR numbers show that I was running at a restful, LSD pace. I've been running via "feel" for 34 years, and it was nice to know that my "feel" agrees with recommendations for a restful run. I won't be using the HR monitor as a normal thing, but starting in January, I will use it to check on my "feel" during my speed work during the spring. I want to continue running via "feel" but would like the assurance that my "feel" is about right.
By way of information, my wakeup HR was 49 this morning, 32% of max. While using my computer, my HR is about 39% of max. While walking around it is about 47% of max.
By way of observation, I was surprised how quickly my HR came down after I stopped running and began walking for a cool-down. Within 100 feet of walking, my HR dropped about 10 points. I walked about 1/4 mile and did stretches for a couple of minutes. When I finished all of that, my HR was down to my "walking" value.