At the Gym
Throught all of human history until very recent times, people performed far more physical activities as part of their ordinary lives than most of us do today. Today in modern countries it's possible to live with only the very bare minimum of physical exertion.
God didn't build our bodies to function in this way — so it's important to make up for that if you don't have a job (or other activities in your life) where you use your muscles regularly.
