A Canadian study suggests that regular physical fitness improves cognitive function.

Physicians have fully established that integrating cardiovascular workouts into your daily routine can preserve good health. Now there is evidence that regular exercise also improves mental fitness, especially in adults who were previously sedentary.

A new study presented yesterday at the Canadian Cardiovascular Congress, took a close look at the benefits of exercise on middle-aged adults who were otherwise overweight and inactive. Led by Martin Juneau, M.D., F.R.C.P. and cardiology director of prevention at the Montreal Heart Institute, the study measured patients’ body composition and cardiac output prior to them beginning a regular, twice-weekly exercise regimen. The pilot study also measured patients’ cognitive function and blood flow to the brain, and found measurable improvements after just four months of exercise. The results appear to demonstrate that regular aerobic exercise not only improves cardiac health, but can also improve brain function, executive decision-making, mental stamina, and memory—all attributes that decline as we age.

After four months of high-intensity interval training, heart patients in Juneau’s study had markedly improved cognitive functions: the ability to think, recall, and make quick decisions. Even more exciting is that the study demonstrated that the more exercise patients could tolerate, the better their results—their minds became “sharper.”

“It’s reassuring to know that you can at least partially prevent a decline in cognitive function by exercising and losing weight,” says Juneau. “If you talk to people who exercise, they say they feel sharper. Now we’ve found a way to measure that.”

For the study, Juneau measured blood flow to the brain both before patients began their regular exercise routines. Other comparative measurements were also recorded, including patient weight, body mass index, cardiac function, and their maximum ability to tolerate exercise.

In follow-up testing done four months after patients began a twice-weekly exercise program, which included cycling on a stationary bike and circuit weight training, their positive results fell in line with the amount of exercise they endured. Tests showed the more people could exercise, the greater their cognitive and physical improvements.

“At least 150 minutes of moderate-to-vigorous physical activity per week can make a huge difference to manage risk factors for heart disease and stroke,” said Beth Abramson, M.D., Canadian Heart and Stroke Foundation spokesperson. “There are many benefits of exercise. We know it can make us feel better. This [study] suggests it can make us think better as well.”

We already understand that regular aerobic exercise is essential for optimizing heart and lung function and maintaining a healthy weight. Now growing evidence suggests that exercise also plays a role in preserving brain function.

Even so, only about 30 percent of adult Americans report getting regular physical activity according to the National Center for Health Statistics. Similar reports also suggest that Americans grossly overestimate the exercise goals they do meet.

Similar studies showed that exercise improves brain function in several ways. Those may include neurogenesis (creating new nerve cells), improving the function of neurotransmitters (chemicals that transmit nerve impulses), and improving vascular function (creating new blood vessels).

A 2009 study reported in Trends in Neuroscience showed that “physical activity improves cognition and may delay age-related memory decline.” That same report showed that exercise protects against stroke-related brain damage and promoted faster recovery after surgery.

Other studies, such as this one from 2010, suggest that brain volumes are actually larger in adults who are physically fit. In that randomized control study, aerobic exercise “increased the size of the anterior hippocampus, leading to improvements in spatial memory and increased hippocampus volume by two percent.” The hippocampus is among the first regions of the brain to suffer damage due to Alzheimer’s disease.

Another 2010 study, this one published in the Journal of Psychosomatic Medicine, showed modest but consistent “improvements in attention and processing speed, executive function, and memory.”

In 2011, Harvard Health reported that regular exercise can “reduce levels of the body’s stress hormones, such as adrenaline and cortisol [and] stimulate the production of endorphins, the body’s natural pain killers and mood elevators.”