Unless you have rollers fitted with some kind of resistance unit, I agree with what Carleton just said. Does anyone here train with this kind of set up? I've often wondered how it would work. I like riding rollers, but the conditioning is limited as carleton said, and I find a fixed trainer to feel unlike actually riding a bike. Maybe this would be a winning combo? I've never tried, but will be in the market for a new set-up soon.