tortoises and hares

[anotheranon]

Ever since I started exercising (semi) regularly, I've bitched about how crap my endurance is (one example). As I kept going on I started wondering whether some people aren't just inherently suited for one type of exercise or another - long, marathon-type activities or short, sprinting activities - myself being mostly suited for the latter, because I seem to burn out fast and modern fencing is, after all, largely short sprints while holding a weapon....

Conversations about this have revealed to me the existence of slow- and fast-twitch muscle fibers. D. says he first learned of this in junior high and I'm sure almost everyone else who has ever pursued a sport seriously has heard of this, but it was news to me! A hideous oversimplification of what's at the link: skeletal muscles all have some combination of slow twitch (slow/high endurance) and fast twitch (fast/low endurance) muscle fibers. Most people have more of one type than the other (I'm not even getting into medium-fast twitch muscles - look at the chart at the link).

There seems to be some confusion over whether one fiber type can be changed to another with training, or just how much influence the fiber combination has on actual performance, but it seems the only conclusive test of what proportion of fast/slow you have is a muscle biopsy.

Seeing as I'm not curious enough about this to get a needle rammed into my leg, I'm going to guess based on past experience that I'm mostly fast-twitch - my limit for fencing (both small, fast foil and heavy, precise rapier) tends to be about 2 hours before my technique goes to hell and there's little point in continuing. Hell, even standing hurts after only a couple of hours :(

So what to do? The first link seems to suggest that trying to be a "tortoise" when you're built like a "hare" won't work well and will likely ruin your hare-like strengths: in other words, I could work on my endurance only at the expense of speed/power, and would never build really good endurance anyway. On the other hand, the connection between muscle fiber type and performance isn't completely clear and it would be nice to be able fence without wiping out so fast.

No conclusions as yet, but I've found reading up on this to be fascinating.

Comments

[anotheranon.livejournal.com]

You may be no expert, but you've done serious exercise longer than I have! You do make an excellent point - endurance is, by it's very definition, something that likely isn't going to come naturally.

Still, it's interesting to consider the possibility that everyone has to start somehwere, and there might be a physical influence on where different people start.