Physically active
When you do exercise, it increases your heart and respiratory (breathing) rates, and speeds up pretty much all of the functions inside your body (including metabolism). It also lowers your blood pressure long term. Staying still and not doing anything lowers rates such as food absorption, and also means that you build up fats, making it harder to become active again. The slower your metabolism is, the harder it is to lose weight and make it faster. So you are better off staying active and not letting it slow down in the first place.
