Resting vs exercise

I know that when fasting it is generally good to rest as much as possible so that your reserves will be conserved for healing. However, when fasting to remove a tumor such as a fibroid, wouldn't you want your body to be forced to dig into those reserves more quickly so that it will use the tumor faster? If so, would that mean you should exercise more than for other kinds of healing? (I am speaking of light exercise of course).