A really strange morning for weather. These two pictures were taken minutes from one an other, the first at 12:45:58pm, and the second 12:47:44pm. All morning it alternated from whiteout blizzard-like conditions to bright and sunny separated by minutes of one an other.
Tonight was a skating night, and my first with my Bluetooth heart rate monitor. I've wanted a detailed set of data from a full skating session for a long time, and tonight I would get my first one. Overall the session was slower than I would have liked. There were two parties in the evening session and a lot of novice skaters meaning I had could not keep speeds high. There were two time, however, I was able to open up. Because of the crowd the rink did a song of only advanced skaters where we all formed a line and moved pretty good. Then at the end of the night when the session ended I continued to skate with a small group of people on the floor. At this point I was at 2,400 Calories burned--100 short of my 2.5k goal. With a mostly empty floor and opened up and at an average heart rate of 186 BPM (101.6%) for 4 minutes 15 seconds, burning 100 Calories. For my weight and height, 100 Calories is about what I normally burn in one hour, and I did it in less than 5 minutes after already skating for 3 hours.
Now, the part I've been looking forward to: data analysis. The pure graph of my heart rate over time isn't terribly interesting. I was able to see times I skated pretty fast, and times were I clearly wasn't on the floor. What is more interest is the histogram of the times I spent at various heart rates.
Here is a histogram of how much time was spent at various heart rates. Most of that the time I was between 150 BPM (82%) and 180 BPM (98%). The lower times would be when there was a slow song or a game where I couldn't be on the floor.
This cumulative histrogram shows what percentage of the time was spent at or above some heart rate. For example, I was at or above 97% (177 BPM) of my maximum heart rate for about 15% of the total session or around 27 minutes. Half my time (an hour and a half) was spent at or above 87% (160 BPM). According to Haskell and Fox formula, 80%-90% of one's maximum heart rate is anaerobic exercise, and anything above 90% is "maximum effort" (whatever that means). This data tells me I spent 67% of my time (2 hours) in this zone. That isn't possible because anaerobic means "without oxygen" and anaerobic exercise means the heart cannot keep up with the oxygen demands of the body. Clearly I cannot be doing that for 2 of 3 hours and live. Everything I've learned about fitness seems to differ depending on who is writing it, so this doesn't surprise me. And without good data to compare my own against, it is hard to get a sense of how good my body is actually preforming.
The last bit of data: heart rate recovery. At the end of the night I did a hard push, holding my heart rate beyond it's estimated maximum. I've read that this is safe as long as your heart slows down quickly afterward.
Here we have my heart rate starting at the high point of 188 BPM when I stopped my head push, falling over 2 minutes (x-axis in seconds). In that time my heart rate dropped 64 BPM, well in excess of the 22-52 BPM for normal recovery. Based on this information I can conclude my heart is able to deal with the heavy demands placed on it by skating.
I really like having the raw data like I do, although my spread sheet software isn't fond of working with 10,000+ rows of data. I may have to write some custom software to better break down the numbers. There is more data in the numbers and I've just started to play with it. Looking at the numbers from when I started skating in the evening, it took about 4 minutes 20 seconds to warm up and get my heart rate to 170 BPM (93%). I can tell because after I warm up, I take off my dress shirt, and I can see a drop in heart rate as I place my shirt in a locker. So lots of data--just need to analyses it more.