Wednesday, May 26, 2010
Muscle Fiber Composition, Exercise and Learning
I hate push-ups but I like the bench press - essentially the same exercise. Now that I only do bodyweight exercises I've come to re-examine the push-up but I doubt it will ever be something I look forward to. I attribute this to learning, since I did a lot of benching in high school and college - starting in the early eighties when the bench seemed to replace the overhead press as the macho gym benchmark.
My wife's family are endurance ninjas, I'm convinced they are all 98 percent slow twitch fiber. When I go hiking with them it just sucks, I'm always the straggler, and I grew up at 6000 feet damnit! I think Slavs in general have a high composition of slow twitch fiber. There are lots of different types of muscle fiber, and the categories still seem to be in flux. My composition seems to be biased towards speed and certainly not strength or endurance. I ran 200 and 400 meters in high school and seem to have inherited much of this from my Father who was a world class quarter-miler in his day although he can put on muscle much easier than I.
So where is this all going? Well, I'm wondering what natural inclination, i.e. fiber composition has to do with preferred exercise. I like to bench press because I spent (i.e. wasted) plenty of hours of my youth laying on a sweaty, red plastic bench (usually with sparkles - yeah the 80s). But I also like sprinting a lot more than jogging. I did a lot of interval training in high school so that could be a big factor. Or it could just be that I prefer exercises that match my fiber composition, certainly it is some combination of the two. But what is the proportional contribution of learning and inclination?
When I switched from jogging to sprints, mostly thanks to Mark Sisson, running seemed like less of a chore, was reduced in frequency, and I tended to feel better afterwords (which I mostly attribute to the fact that sprints are more difficult to overdo, at least at my age, so intensity tends to fluctuate according to what the bod is ready for).
I've been subtly trying to get my wife to add sprints to her jogging routine ("Cardio sucks, it is making you less healthy"). She's been fiercely resisting my sage advice ("Could you change the cat box while I am gone?"). So I've begun wondering whether she likes endurance exercise more than me because that's what she's designed for (and the opposite for me), and how much early experience of specific types of exercise influence one's exercise decisions later in life.