Too Much Exercise: Too Much of Good Thing?
Many of us made a new years resolution to be more healthy, and activity is one component. Everything you read tells us to be less sedentary, and many of us will try to be less inactive this year. Exercise decreases the risk of cardiovascular disease, diabetes, and metabolic syndrome. The benefits of more exercise are clear, but working out too much may have the opposite effect. When you decide to turn to a healthier lifestyle, we often overdo it, but can you exercise too much?
I have watched active duty Soldiers overdo it at work. They wait too long to get ready for a field exercise, deployment, or physical fitness event and they suffer a heat injury. Heat injuries and compartment syndrome are just two possible overexertion injuries that happen when you overdo it. Most of us will only get a little sore and have trouble getting out of bed in the morning, but people die every year due to increased exercise.
A recently published study, “25-Year Physical Activity Trajectories and Development of Subclinical Coronary Artery Disease as Measured by Coronary Artery Calcium: The Coronary Artery Risk Development in Young Adults (CARDIA) Study” from November of 2017 looked at this very question. The researchers looked at the physical activity and the risk of coronary disease for over 3000 healthy young adults over 25-year history. They used a coronary calcium score to evaluate coronary artery disease risk. The researchers identified three exercise groups based activity level based on 150 minutes per week. The results identified the upper exercise group who exercised three times the recommended level of 150 minutes per week or more as having a 27% higher risk of coronary artery disease. This result is contrary to what would expect.
The bottom line: Exercise is a good thing, but too much exercise can result in injury or harm. The study seems to indicate that more exercise to the point of extreme if not necessarily better. These findings warrant further exploration. I would recommend that you start slow to avoid a heat injury and limit yourself to less than 3000 minutes per week.