I went through a basic fire fighter course. It was the most physically taxing experience of my life.
Let me say I sweated my a$$ off every day.
We had one guy drop 40 pounds in the last academy. He would have dropped more, except for his eating habits. I took powdered donuts away from him and chewed him out about his diet, but you can only do so much.
Within six months he’ll be back to his donut eating weight.