Friday, May 4, 2007

Marathon Recovery and Twitchy Fibers

Monday: Off
Tuesday: 3 miles
Wednesday: Off
Thursday: 5 miles
Friday: Off
Saturday: 8 miles (projected)
Sunday: Off

Marathon recovery is a bit like a big dessert. Months of sweat, miles, and considerable pain culminate into one race. Hopefully, that race produces a desired result. If so, the recovery can be an enjoyable time of easy miles and loads of food. That is precisely what I have been up to this week in regards to training: resting sore muscles and weakened tendons along with consuming ridiculous amounts of high-carb, high-protein recovery foods.

The next race goal will likely be the Memorial Day 3k, which is three weeks from Monday. That will give me another 1-2 weeks of recovery, then 1-2 weeks to sharpen up with a few speed sessions and see how much my marathon training impacted my speed in shorter races. Certainly, all that running would make a runner faster at any distance, right? Well, that's not quite the case, biologically speaking.

A person has two general types of muscle fibers: "fast-twitch" (better for sprinting and shorter races) and "slow-twitch" (conducive to distance running). For most, the ratio is about 50/50, but elite sprinters could have as high as an 80/20 fast/slow twitch ratio. Conversely, some elite marathoners have 80/20 slow/fast twitch ratio. This seems to be determined genetically.

Research has shown that by marathon training, some fast-twitch muscles fibers can be trained to take on the characteristics of slow-twitch fibers. They only way to know an individual runner's ratio is to have a cross-section of their muscled taken for research. Even at that, there is not much that a person can do about it.

All this to say that training for the marathon could conceivable make a runner slower in shorter distances. I will find out if I have been made fast or slower within the next month in the upcoming 3k and the Summer Classic 5k in Brownsville (Edmonson County) in June.

1 comment:

Travis said...

Sometimes reading your blog makes me hurt.

The thought of a cross section of my muscle fibers made me cringe. And I don't even have much muscle fiber.

Is it possible to have "no twitch" muscle fiber?