I do some hard exercise on Mondays. I work out with a group of colleagues, who have arranged a personal trainer to come to school and run a session with us at 5pm. As a reward after a hard workout, I have been buying (during my lunch duty at the canteen) a little box of chocolate milk. I have been enjoying it on my way home.
Today I had a brainwave. I brought in my empty water bottle, with a scoop of vanilla protein powder in it. Then I poured in the chocolate milk, shook it up, and stashed it in the staff room fridge. Then afterwards I had a wonderful, cold, creamy drink; a great reward!