Indoor vs Outdoor

I always hear that riding indoors on a trainer is equivalent to riding outdoors for a longer duration. Every podcast on cycling I have listened to, or YouTube cycling channel, seems to mention this at some point. I understand the thought process behind the statement but have yet to hear of any studies to actually back up this claim. So the question(s) are: Are there any studies to prove this, and if so, what is the ratio of indoor versus outdoor duration? Thanks @trevor @ryan

There are studies showing that power indoors tends to be lower, but I’m not aware of any that compare the adaptive response of indoor and outdoor training directly.

Apart from the convenience aspect, my understanding on the effectiveness of indoor training is largely down to the constant pressure on the pedals without the freewheeling and stop/starting you get outdoors. I don’t think you could ever give a set ratio though as it would very much depend on the route/terrain you are comparing it to and what specifically you are targeting to train.

Hi @Gravity_Cat,

That’s a good question and unfortunately, I’ve never seen a study on the subject. From my understanding, the claim is based on two things:

  1. When you’re outdoors, you’re going to have a lot more non-pedaling time. When you’re on the trainer, you’re going to be pedaling pretty much the whole time. So, at the same effort, you’re actually going to generally do more work in an hour.

  2. The biomechanics are different. Outside on flats, you’re going to have a dead point in the pedal stroke and be able to use inertia a lot more. On a trainer, there’s little inertia and you’re going to get resistance throughout the pedal stroke which will increase the length of your power stroke. So, theoretically more work per stroke.

That’s the theory. But, haven’t seen any research to actually prove it.

Hope that helps!