Originally Posted by
TimothyH
Wind resistance has less to do with it than people here imagine.
You are not accelerating your body mass on a trainer, nor is energy required to keep that mass in motion.
It takes less energy for 150 or 200 lb to remain stationary than it does for the same mass to stay in motion.
-Tim-
Uhhh... inertia is a property of all matter. An object in motion stays in motion unless there is an opposing force to slow it down. In our case, that opposing force is mostly gravity (on climbs), atmospheric drag (wind), rolling resistance, and mechanical friction of the bicycle's drivetrain.
On a flat road, the biggest energy sink is drag, followed by rolling resistance, then drivetrain friction.