Frequency and sleep are certainly important factors. Stressing your bones from time to time lead to hairline fractures that get repaired and cause your body to strengthen the area, leading to stronger bones. But doing it faster than the repairs catch up leads to a stress fracture [1]. That happens even from what we consider normal loads (running, jumping, etc) if you aren't used to them and then suddenly experience them very frequently.

The same is true for countless other physical and psychological processes. Some stress is great, but you have to be very careful if you lack buildup or recovery periods.

1: https://en.wikipedia.org/wiki/Stress_fracture