The deterministic-coupling-between-exercise-and-fitness thing is a good idea, but I'm worried that the OP has ignored the vital, crucial importance of doing something wise with your daily hour of fitness. If you're a fitness n00b and spend an hour a day doing steady-state cardio on the treadmill, your results will be hilariously worse than if you implement a formal fitness plan that has worked for lots of other people such as [0-1] or similar. All "exercise" activities are not created equal.

[0] Mark Rippetoe's Starting Strength [1] Lynn MacDonald's Body Recomposition