system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does driving exhaust you so much? You’re sitting, barely moving any muscles in a comfortable air conditioned rectangle.

Thinking about exercising for 3+ hours versus driving for 3+ hours. 
I’d have more energy it seems after the exercising.
Driving makes me tired.
gpt
Part of it is mental. Driving typically takes a lot of constant concentration and small adjustment. You're also more or less sitting immobile for that whole time, so your body gets stiff.

After a few hours of that, stiffness plus mental exhaustion feels pretty similar to physical exhaustion.