Here's a shocker: Prolonged sitting is bad for your health – and bad for your back, thanks to too much spinal flexion. Counter the effect by standing every 20 to 30 minutes while at work or lounging at home. To help remind yourself, McGill recommends standing every time the phone rings, you get new email, or a commercial comes on while you're watching TV at home. Then, several times a day, stand up, push your hands toward the ceiling, and inhale fully and deeply for 30 seconds. The exercise will help stretch your lower back and "reset its stress clock," says McGill.