There are some weird results in exercise science related to this. For example, if you perform exercises only on one side, unilateral strength on the other side improves (something that seems like a pointless novelty until you consider training while injured). There's a huge amount of strength that relates to 'neural' factors.

Conversely, apparently elevated heart rate due to gaming does not improve aerobic fitness.

So I'm thinking that, broadly, there will be no such thing as a free lunch here (as per usual).