Your leader makes you lift heavy loads with all your power, since this is what you do for work. Why do you do this kind of work? Well, you're good at it and the leader makes you do it, I guess.

Where do you get the power to do all this work? From doughnuts (どう). You eat nothing but doughnuts. If you had no doughnuts, you couldn't work. In fact, your leader pays you for your work… in doughnuts.