A base layer of short sleeve Under Armour, a layer of long sleeve Under Armour, an Under Armour turtle neck, two Nike long sleeve pull overs, bottom Under Armour shorts and tights, a pair of running shorts, two hats, and two pairs of gloves. This was the amount of clothing that I needed to wear to be able to run outside today…and it still wasn’t enough (my legs were a little wind burned by the time I was done). When I left the athletic center this afternoon, it was 1 degree Fahrenheit and very windy. Many friends believe that it was crazy to run outside for eighty minutes today. Maybe it was, but running inside breaks one of my cardinal rules about running. I believe that unless you are really sick or injured, there isn’t an excuse to stay inside and use the stationary bike, elliptical, or treadmill. Running outside today definitely took a toll on my body but I’m too stubborn to reconsider training indoors.
The weather today got me thinking about what we had learned in class the other day about the mammalian diving reflex and how when the human body is submerged in the cold or, more specifically, cold water, heart rate slows down up to twenty five percent. I definitely don’t think that my heart rate dropped a full twenty five percent, but I do believe that it slowed a little bit due to the cold today. My junior year of high school, my high school coach used to have me wear a heart monitor while running. I calculated my max heart rate based on a VO2 max test and then used it to find out what 50%, 60%, 70%, etc of my max heart rate was. I ran most of my mileage back then around 60-70% of my max heart rate, which equated to roughly 150-155 beats per minute (not sure what my max heart rate was calculated to be at the time, but I do remember that most of my runs were about 150-155 bpm). Today, I ran at my perceived 60-70% of my max heart rate for ten miles. I came up with the idea to check my heart rate just after finishing the run to see how close it was to my predicted 150 beats per minute. Unfortunately, as I approached the athletic center, I was too focused on getting in and getting warmed up as soon as possible, so I initially blanked and took my heart rate slightly after I had stopped running.
I did a more general version of finding my heart rate after my run. I simply counted the number of heartbeats over a six second period and multiplied the number by ten. I counted 13, meaning that my heart rate at the time was roughly 130 beats per minute. This is interesting because I estimated that my heart rate while running should be between 150-155 beats per minute at my perceived 60% of my max heart rate. It’s too hard to tell if my heart rate was at 130 when I measured it because of the temperature or if it was because I didn’t take my heart rate immediately after stopping. I’m assuming that the sudden decrease was because more because of the extra time elapsed between stopping and checking my heart rate.
While I realize that there are too many unknown variables and estimates to draw any definite conclusions, I wouldn’t be surprised if my heart rate dropped a little bit because of the temperature today. I guess the only way to truly find out would be to try to get my hands on a heart monitor and try it again in the near future.
And yes, I realize that trying to tie mammalian diving reflex into the title was a huge stretch.