Are you at work? Are you sitting at a desk? Are you just sitting in general?
Now get up.
Walking around the office will get your blood pumping, your head cleared, and your metabolism back in action.
Reminding yourself to get up once an hour to walk around the office (go get coffee! take the long way to the bathroom! go talk to your coworker instead of emailing them!)
I challenge you to get up at least 5 times a day to stretch, take a walk, etc! Now GO!