Previous studies have found that prolonged sitting can raise the chances of heart disease, various cancers and an earlier death. In the new research , experts combed through 13 papers with data on factors including how long people spend sitting, their physical activity levels and their television-watching habits. Researchers found that people with the highest levels of moderate physical activity — 60 to 75 minutes daily— erased the higher risk of death linked to being seated for more than eight hours a day. Lars Bo Andersen, who co-authored an accompanying commentary , called the new research "very convincing," explaining that too much sitting increases the risk of problems including diabetes and heart disease because it can make insulin levels spike and might slow the body's metabolism.