Originally Posted by
zacster
But here's the thing I still don't get, how is it I can put out more watts on the road using the same power meter for both? And I can understand that the outside riding is less consistent than the trainer, but I just checked average watts over similar timed rides and the outside rides are always a good 20w greater, and these are frequently less grueling and include easy street riding. I'll feel totally beat up on a trainer, and it worked wonders over the winter. My HR also bears this out. I have a higher HR on the trainer for the same watts.
What's been explained to me in the past is that, among other things, poor heat dissipation and oxygen depletion can be problematic indoors, even with a multi-fan set-up, and that it's fair to assume that outdoor performance will better than on the trainer. I would also imagine that the freedom of movement on a ride would allow for the recruitment of other muscles vs the trainer, too, but that's just a WAG.