Climbing up the ladder help works your leg and arm muscles.
Carrying a toddler on you hip while talking on the phone. helps with your hips, stomach, arms, and legs.
Using a bow and arrow would help with your arm and upper body strength.
Scoring goals is often helpful
Well... A complicated risk has to do with your metabolism. Under most normal circumstances your body will use glucose and oxygen to make energy. When however you don't have the glucose your body is able to use fat for energy. However if there is to little fat and your body needs energy than you run the risk your body metabolizing your muscles. Of course this is dangerous and quite unpleasant, but an even more dangerous complication is the acid waste that results which can cause acidosis.