Your heart isn’t the only organ that can benefit from regular running: The more fit and active you are, the less likely you are to develop glaucoma, a serious eye disease that can damage your optic nerve and even lead to blindness, new research set to be published in Medicine & Science in Sports & Exercise finds.
In the study, researchers analyzed data from more than 9,500 people between ages 40 and 81 enrolled in a long-term study at the famous Cooper Clinic in Dallas. The researchers compared the subjects’ aerobic fitness (measured by treadmill tests) and weekly amount of exercise (reported by the subjects) to how many of them developed incident glaucoma during a nearly six-year follow-up period. The researchers specifically looked at incident glaucoma, the more common form of the condition, rather than traumatic glaucoma, which is caused by direct injury to the eye.
The researchers found that those who were the most active and the fittest had only half the risk of developing glaucoma as the least-active, less-fit group. Running 10 miles per week at a 10-minute mile pace would be enough to rank in the study’s fittest, most-active category.
This isn’t the first time scientists discovered a vision benefit to running. This new research builds on a study published in 2009. In that study, which involved only runners, those with the highest mileage and best 10K times had the lowest rate of glaucoma, compared to lower-mileage and/or slower runners. The new study strengthens the pro-running evidence by including sedentary people as well as casual exercisers who are less active and fit than runners, and by showing that modest mileage appears to bring significant eye-health benefits.
So why might running lower your risk for glaucoma? As the new study states, “intraocular pressure is the primary modifiable risk factor for glaucoma.” When pressure in your eye is too high, it can damage the optic nerve in your eye, potentially leading to glaucoma.
Other studies have found that a single workout reduces intraocular pressure, that the reduction is greater following more intense workouts, and that higher levels of fitness are associated with lower underlying intraocular pressure. Taken together, these findings suggest that exercise that’s frequent and intense enough to boost fitness, such as regular running, should lower intraocular pressure enough to make a significant difference.
And the glaucoma reduction might not be the only eye-related benefit to running: Separate research by the 2009 study authors found that the more people ran, the less likely they were to develop cataracts during a six-year follow-up period.
Although few people probably take up running to help their eyes, you have to love research like this that shows just how profoundly regular running improves nearly all aspects of your health.