Muscular Atrophy?

Increased muscle activity under a load will cause the muscle fiber to increase in size… hypertrophy. Though hypertrophy of the muscle decreases after a workout, some of the increase in size will be longer lasting. However, prolonged lack of overload or muscle activity will result in a decrease in the size of the fibers. Atrophy can result from lack of exercise in as little as 48 to 72 hours and will continue if the muscles are not exercised in regular intervals.

Since atrophy will be proportional to the stress put on the muscles, does anyone know if the amount of stress is proportional to atrophy? In other words, would working the muscle more intensity than normal also cause it to rebound the other way if left inactive for a certain amount of time?