Movement breaks are designed to get you up and moving every clock hour (the mission resets on the hour). The goal can be completed in a variety of different ways:
Getting a glass of water
Taking a bathroom break
Doing an active stretch
It can be anything that gets you and your phone up and moving for a short period of time. It is important to remember that it only takes a small number of steps every hour to complete this goal!
In order to remind you to take a break, it is helpful to set a reminder on your phone. If you have an iPhone, the automatically downloaded app "Reminders" allows you to receive a notification every hour!