> You will need to increase that time in order to see continuous benefits

If you don't increase, do you lose any benefits you gained? A few years ago I made a modest workout plan because I wanted to be a bit stronger, a bit more flexible, and have more stamina. I achieved my goals and flipped into a maintenance mode where I basically do just enough exercise to stay where I am. By not pushing for new bests, am I no better off than if I had done nothing?