Middle-aged people who do not frequently exercise may have lower brain volume over time. Brains shrink as they age and this fact may be unavoidable. However, recent research suggests certain things can speed up the shrinking: “the new findings add inactivity to a growing list of factors like smoking, obesity, diabetes and high blood pressure that are thought to accelerate the process… The study included 1,583 people enrolled in the long-running Framingham Heart Study who took a treadmill test to assess their fitness levels…two decades later, people with below average fitness in the first test had smaller total brain volume than the others. Each 8 mL/kg/min of exercise capacity below the average performance level in the first test was associated with enough reduction in brain volume by the end of the study to amount to two extra years of brain aging, according to the results in Neurology.” The study urged older people to start to exercise—at least 2-3 hours per week—to prevent any rapid aging.