Healthy living starts with standing up. You certainly wouldn’t know that from the way Americans operate. We sit on our commutes. We sit at our jobs. We sit in front of our home entertainment systems. These behaviors must change, though, if we want to lead heart-healthy lives. Earlier this year, researchers published a report in the Annals of Internal Medicine demonstrating that sitting extensively increases the likelihood of life-threatening illnesses – even for those who work out regularly.