Sunday, September 22, 2013

Playing with my heart rate

I am newly energized to look at my heart rate when exercising, thanks to my friend's recommendation to read Younger Next Year. I remember I got my first heart rate monitor in 1998, during the time of my Big Loss, in Texas on a business trip. I was fanatical about daily workouts on my Nerdic Trak in those days, but not ready to go to a hotel gym where I might see someone I knew. So I was out for a walk in the not-pedestrian friendly suburbs, and found a sporting goods store. I was extremely ignorant, looked at the watches, and didn't even realize it came with a chest strap till I got to my room and unpacked it.

It did open my eyes about how hard I was or was not working. I was extremely surprised how little correlation there was between my subjective feeling of how hard I was working and what showed on the heart rate monitor. Likewise, the NT has a speedometer but on different days the same speed took different levels of effort on the heart. A couple of times, I couldn't push the heart rate up high at all, and later that day I realized I was sick with a cold. I would have figured differently, that the heart would race when ill, but at least in these cases, not so.

Today I was down on the treadmill for a serious workout. I still have illusions about doing a 5K in less than a month but I haven't even been walking that far, so I need to buckle down. Intervals are the way to go, but I'm not able to progress as fast as my Couch-to-5K schedule I used last time. Still, I dream of running easily along a trail, smiling, working, but not killing myself.

Heart rate zones have gotten more complicated than back in 1998 when I applied the classic formula to understand my workout zones. The classic max heart rate is 220 minus your age (which yields 162 for me). Then simple percentages give zones: 65% is 107, 75% is 121, 85% is 138, and 150 is 93%.

I think these are too low for me now. Fifteen years ago, I comfortably worked out on the NT with the heart around 135 beats per minute, which should have been around 75%. I can still do that rate, but now that is around 85%, by the classic formula. There are many other formulas, and I have no doubt I'll read up and figure it out, but not today.

Today's fabulous workout was focused on working my heart rate, but I pushed it up higher than the formula would have recommended, but it felt right. First, I ran four intervals, aiming for 3 minutes running and 90 seconds walking, but adjusted to what my heart was saying about how hard I was working. I slowed down the speed on the treadmill, because at 6 miles per hour I just work too hard too fast. So I only went to 5.5 mph. The first three minutes got me up to 138 only. After a minute of walking, I was down to 120. After that, for the next three intervals, the heart realized I was serious and climbed higher. Each time, I let it get to 150 and then kept on pounding along for 30 seconds and then slowed down.

After the intervals, I walked. I do not like to walk fast. 3.2 miles per hour, or 3.3, is a very comfortable cadence for me. I just don't get comfortable at faster speeds, and the classic 4 mph has me breaking into an uncomfortable jog. Must be short legs. But I've learned I can get the heart rate up by increasing the incline of the treadmill. So I finished out the 3.11 miles by holding my heart rate around 135 by varying the tilt at a constant speed. I started out at a steep incline, and the heart rate drifted up so I backed off. As it went down, I could bump it back up by making a bigger hill. I got into it, and I found the pace quite comfortable, like I could keep it up all day. Except, not really. I was thrilled to come to the end.

A shower and stretching and I feel great. Blew the dust out of the pipes. The trick is to keep moving for the rest of the day.

- Posted using BlogPress from my iPad

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