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Whenever you take a fitness challenge that is relatively extreme compared to your current workouts and fitness level, you are risking injuries that could set you back for months.
That’s the very definition of the law of diminishing returns: The more you do something to an extreme, the fewer results you get from it.

Besides, the term “extreme” is relative. For an advanced-level exerciser, doing 100 pull-ups in a workout is not a problem. However, for a beginner, doing just one might be impossible.

SOURCE:

https://www.military.com/military-fitness/military-workouts/daily-pt-challenges-law-diminishing-returns#:~:text=Whenever%20you%20take%20a%20fitness,results%20you%20get%20from%20it.