Morning Rounds: What's good for the heart

CBS News chief medical correspondent Dr. Jon LaPook and Dr. Mark Pochapin, head of gastroenterology at NYU Langone Medical Center, join “CBS This Morning: Saturday” to discuss a new study examining the link between exercise and cognitive decline in older adults. Also, March is National Colorectal Cancer Awareness Month; and a long-running Harvard study may provide an answer to what keeps us happy and healthy as we go through life.