This short guide is about tonus and stat capping.
Tonus Explanatory Guide
Some punches or kicks reduce your attributes while using it, it says that in the description.
Like -1 per round of fighting. So if you use a strength kick that has -1 str per round and put it 4x in your slots you have -4 str after one round.
The complete reduction is shown above your attribute with the current value.
To regain your str you need to train, this first puts your tonus back to 0, then it continues with your stat increase.
Training your tonus back up is faster than normal training.
Tonus refills really fast, don’t worry about using it during fights if needed.
I would usually just use the broken machine that you need to repair in Silver’s Gym to also refill tonus, however it’s way less effective late-game.