I never ride my bike indoors so I shouldn’t really have any opinion. But to me it seems like a completely different thing. Not because “real” riding is more difficult (actually, in my opinion riding on a trainer would be more challenging! what do you look at for all those hours?), but because it’s a different experience (and I think more fun).

So my opinion is that you should do both and you will have two different achievements :)

it’s like masturbation is to making love with your sweetie – it takes care of a certain physical need, but isn’t the Real Thing.