Posts Tagged ‘physiology’

h1

#50 – Running a Fever

27 February 2008

Most of the time the word “running” evokes positive thoughts – running with dogs, running on trails, running for fun, running a race, running to be alive.

Notice that “running a fever” is not one of them, nor is “runny nose” or “running to the store to get medication”.  Recently I came down with the flu, apparently for the first time in my adult life because I have never felt so physically miserable before!  Even the low point of my first ultramarathon didn’t feel so bad in comparison.  Also for the first time I had to call in sick at work as my wife and I were both non-functional on Monday.

I awoke that morning after a night of fruitless attempted sleep and staggered down the hallway to the easy chair, where I remained for the next few hours, unable to move.  Despite doing nothing but sitting, my heart rate was around 120 bpm!  More than double my usual resting pulse.  My body was working hard but I wasn’t going anywhere.

Finally I took my temperature and was stunned to see the mercury lined up with 102.5 on the scale!  I drank a couple glasses of ice water and an hour later my temp was down to 101.8 and I was feeling much better.  Another hour went by and the thermometer read 101 flat, which I maintained the rest of the day.

I wonder if my system was overheated due to the fever?  Being unable to thermally self-regulate, an external cooling source (ice water) was required to bring my physiology under control.  The high heat of a fever is beneficial to the immune system and it’s also a more hostile environment for the virus, but apparently 102.5 was borderline too hot for the rest of the body.

Interestingly, according to a fascinating article about exercising in the cold from the bloggers at The Science of Sport, the human body quickly heats up to about 102 degrees during physical exertion.  Maybe running a marathon isn’t quite so different from running a fever after all!

We need look no further than the 2007 Chicago Disaster to realize that 102 degrees of body temperature is very close to our physical limits.  When stressed to the point of being unable to thermoregulate, many marathoners in Chicago required external heat control (such misting fans or ice cubes handed out by spectators) in order to maintain a safe body temperature.

I suppose I could’ve stepped outside into the subfreezing Michigan winter to cool off, but I’ll save my physiological challenges for my foot running not my fever running, thank you.  Besides, hydration is quite important when sick, giving my ice water remedy a double-whammy of effectiveness.

Hydration, thermoregulation, heart rate…  is there any other way to relate the flu with running?  Why of course – body fat.  Two days of no appetite resulted in a net loss of seven pounds, a fat-burning trait that my body would do well to make use of during my next ultramarathon!

Advertisements
h1

#40 – Frazz Understands

28 November 2007

Back in April the inaugural article on this blog was about heartbeats and life expectancy and it has been one of the most popular posts ever since. The concept that we may have a finite odometer attached to our heart is a fascinating one, and it’s one of the best motivations to get out there and run.

FrazzJef Mallet, the creator of the comic strip Frazz, understands this motivation. Mallet is a devoted endurance athlete and that aspect of himself is projected onto Frazz, the main character in his comics. In the October 28th Sunday edition, Frazz explains why burning up your heartbeats in training can lead to a longer life expectancy.

Does this mean that Mallet was one of the readers of my blog? While I’d love to be a source of anyone’s inspiration, evidence in the Sunday comic indicates that Mallet probably got the idea from an article about the theory of aging by the Santa Fe Institute.

If you haven’t heard of Frazz, check it out, especially if you’re a runner or other endurance junkie. You can probably identify with a lot of topics in the comic; my favorite one I sadly can’t find anymore, but it mirrored a conversation I once had with my brother Ryan that went something like this:

Ryan: Did you go running today?
me: Yeah, but I only did an easy three miles.
Ryan: “Easy” and “three miles” make no sense together!
me: But I was running slowly!
Ryan: “Running” is shooting a layup. Anything measured in miles is too far.

ManateeThe actual Frazz comic is way funnier because it mentions a manatee. I should clarify that Ryan is quite athletic – the only thing he and a manatee have in common is that they’re both intrinsically funny – but he only runs within the confines of a basketball or tennis court. I guess that still counts…

h1

#1 – Conserve Your Heartbeats

1 April 2007

One of the interesting facts about land mammals is that their life expectancy is the same – if you measure it in terms of heartbeats. All land mammals will live for about 1 billion heartbeats. A shrew has a heart rate of 600 bpm (beats per minute) and a life expectancy of just three years. An elephant with their 30 bpm heart rate can expect to live over 60 years. The hearts of each animal will beat 1 billion times in their expected lifetime.

Humans, of course, are the exception – we can last for about 3 billion heartbeats. I’m not sure why – maybe medical technology, nutrition, who knows. Marine mammals don’t follow the pattern either, but let’s stick with ourselves and our 3 billion heartbeats. There are 525,600 minutes in a year, and the average human has a resting heart rate of 72 bpm, so divide that into 3 billion and you get a life expectancy of 79.3 years.

I was talking about this topic with a co-worker when he asked me “So how many days of your life did you burn up by running that ultramarathon?” Holy cow. My heart rate was probably around 150 bpm for the 12 hours it took me to run 50 miles, so in half a day I used up just over a day’s worth of heartbeats! More than that, I ran for 180 hours total in 2006 – that’s 7.5 days of extra heartbeats spent on running! Is it really worth it?

Before I started running three years ago, my resting heart rate happened to be the average 72 bpm. Let’s assume that I lived my first 28 years at that heart rate, which means I used up 1.06 billion of my life’s heartbeats in that span. Now let’s assume that I keep running (or cycling or otherwise keeping in good shape) for the rest of my life. My current resting heart rate is about 56 bpm, so if I keep that up for my remaining 1.94 billion heart beats, I would live another 69 years… to the age of 94!

By getting into (and staying in) good shape, I increased my life expectancy by 15 years! Each year I spend as a runner costs me one week of heartbeats, but the improved fitness adds 13 weeks to my life expectancy for a net of +12 weeks. Another way to look at it: Every month of regular running adds one week to my life! Diving deeper yet… assuming I run 3.5 times per week, that means that each run adds 12 hours to my life. How’s that for a good investment?

Yes, it’s worth it. Assuming, of course, that my clock will tick 3 billion times…