Resting on your laurels - aka your butt - can kill you, experts say. Sitting for long periods of time, even if you exercise regularly, can harm your health. Whether it's at the office, in the car, in front of the TV, on the phone, reading or at school, the more hours you spend reclining increase the likelihood of being obese or even having a heart attack. Researchers have already figured out that we need to move more - preferably 30-60 minutes daily - but new studies have revealed the dangers of sitting, even for those who meet daily fitness requirements. Taking breaks and getting up while sitting at your desk or in front of the TV can help offset the effects of being on your butt long-term. Instead of e-mailing or IMing a coworker, why not get up and go speak to him or her?