Running has always been associated with a slew of health benefits, but a new study suggests that excessive running can lead to earlier deaths. In a recent survey, researchers found that people who participate in high amounts of running tend to have shorter lifespans than moderate runners or even those who don’t run at all. The study, called the Masters Running Group, took responses from 3,800 runners. Their sample was of people 35 years and older, with the average age floating around 46. Of those runners, over 70% of respondents ran over 20 miles a week. Although the results point to excessive running as being linked to earlier death, the reasons for the results are unclear at this point in time. According to one of the head researchers, Dr. Martin Matsumura, they found no differences in cardiac health. They also ruled out medication differences as problems, as both of these variables were prominent factors in the survey. The questionnaire asked participants questions about their running habits, age, use of medications, cardiac history and overall health. They were unable to link any of these factors with an earlier death. If no running and excessive running are out of the question, then what is the optimal length for running? Dr. James O’Keefe, director of preventive cardiology at the Mid-American Heart Institute in Kansas City, suggests 2 to 3 times a week, at a slow to moderate pace, for a grand total of 2 to 3 hours. That’s a far cry from the 70% of respondents who said they ran 20 miles or more a week. Dr. O’Keefe also suggested a possibility that the earlier death rates might be down to the extreme wear-and-tear that the impact-heavy practice of running involves. So if you’re one of those people who runs more than 20 miles a week, it might be time to cut back. Feeling too much pent-up energy? Mix up your workout routine by doing different exercises besides running. Get more involved in weightlifting or yoga – try something that isn’t so tough on your heart and joints. Or, lower your pace and challenge yourself by hiking or going mountain-biking. More than anything, it appears that moderation is pivotal, and finding the right balance in your workout life is key.