Originally Posted by
hhnngg1
I think you're giving Cat3 riders somewhat too much credit. I think a 17ish 5k is more competitive in the running world by a fair amount than the Cat3 cycling denomination, but that's just a guess based on my ability to hang with a good number of Cat3s and my completely inability to run at all at any distance with 17:xx 5k runners.
I was talking specifically about fast marathoners with no fast twitch muscles. You don't need fast twitch muscles to run a fast marathon. Also, 'hanging' with Cat 3s is easier than winning.
I also don't think you're correct about marathoners having a tough time winning Cat3 races. I think as a whole, you'd find more potential in that marathon trained group due to their experience with endurance sports and built up endurance compared to their nonmarathon peers. This whole 'slow twitch' thing limiting performance in cycling is way overhyped, as even in crits where you're doing repeated anaerobic sprints, your endurance is still by far the dominant factor.
Have you won any crits lately? There are a bunch of guys who get to the end of a cat 3 race fresh enough to put out 1200+W. You're going to have a tougher time in a field sprint if you can't put out some decent power over 5 and 30S. It's still possible to win but it's going to take more than a month or two of racing to figure out how.
It's also definitely not true that marathon selects only people with slow-twitch fibers; for the amateurs, it's pretty much a mix of all of them, and test of current elite marathon runners show a real trend toward fast-twitch ratios, meaning they're speedy guys who can run long.
Agreed and I didn't say otherwise. Bigger guys who are fast and have a normal or better than average ratio of fast twitch fibers will do better.
If you look at people's running race results from 5k - marathon, as long as they're trained for the marathon, their performance across race distances are remarkably consistent - it forms the basis for Daniels' VDOT tables and many other similar tables which have very good pedigrees. It's not like guys with fast twitch fibers don't have these Vdot tables apply to them.
True but not in disagreement with what I said.
At a 17:03 5k, you're running a 2:43 marathon. That's faster than the top 0.1% of marathoners in the country, and still in the very top few percent at the qualifier Boston Marathon. I'm pretty sure that's much more competitive than a typical Cat3 performance.
Some guys running 17min 5ks will be good cyclists, some won't. Some will be good climbers, some won't. The requirements for success in a crit are different than for a fast marathon. There is some correlation, but some of what makes a fast runner, i.e. running economy isn't of much use in a bike race.