Cycling and swimming are more complicated than running. Lace up your shoes and head out. We have been opining about form recently, but this is a recent obsession by a bunch of us who had been running for decades before we started worrying about heel strike/forefoot/midfoot strides and hip rotation. Swimming has less gear, but small form breaks can have major consequences. On the bike setup can make major differences, but every body is different.
Max has commented on Chris Froome's awkward position on the bike. Lance Armstrong and Jan Ulrich had markedly different pedaling styles, though both were the best of their highly juiced era.
When I had my tri-bike fitted, I went to an extraordinarily talented fitter who prays at the altar of steep. His goal is to set you up in the most "aggressively aerodynamic" position that you can hold comfortably. I can't really argue with it. At the group workouts I've attended, I've been among the faster riders. At yesterday's workout alternating 3.35 mile laps hard and easy, I averaged 23 miles an hour for the hard laps. For folks who know Prospect Park, my fastest lap was 8:38. My slowest 8:41.
But, and this is a big but, the setup has the seat at the high end of high. This gives me a lot of power, but it also seems to be bothering my hip. My road bike setup is considerably less agressively, with the seat lower and further back. Instead of pulling up on the clips, I tend to pull back with my hamsgtrings. This leads to a quicker cadence, less powerful stroke, but no kink in my hip.
The place where I really noticed the difference was on the spin bike. Spin bikes never fit right. The height adjustment is in 1/2 inch increments. So, when I tried to set up the spin bike to match the tri bike fit, I lost my spin. Last week I went back to my old setup, again, lower and further back. All of a sudden everything feels better (including, knock wood, my heel a bit).
I'm wondering if I should drop the seat a hair on the tri-bike . . .