Hypothetically (no treadmills in sight)
Bicycle: Well built 26 inch commuter bike with tough tyres and simple 8 or 9 speed drivetrain. No suspension or fancy stuff.
Motorbike: I'm no expert - good quality mid range bike you'd use for everyday riding.
If you had a 10 mile commute to and from work each day - which would totally fail first. By fail I mean, to the point you could no longer ride it normally and would need to push it or get it on a lorry.
Neglect punctures and fuel.