If you are looking to start the semester off on the right foot, researchers advise placing exercise high on your to-do list. Although you may be familiar with the positive effects of exercise on the body, a growing collection of research suggests exercise cannot only make you physically fit, but smarter too.
Recent studies show that exercise can help people to process information faster, help the brain to produce new cells and strengthen memory throughout life.
Across all ages, we see cognitive benefits related to fitness,"" said Charles Hillman, associate professor of kinesiology and community health at the University of Illinois Urbana-Champaign.
""Fitness helps to create a healthier mind and body.""
Hillman, an avid athlete since childhood, should know. For years, he has studied the physical activity of the young and old, closely examining the ways that exercise affects the ways that people think. In his most recent set of experiments, Hillman looked at how physical fitness affects cognitive performance in young children, ages seven to ten.
Cognitive performance is determined by the way that children perform on a computerized game that tests the speed and accuracy with which they process information. Hillman tests how ""in shape"" children are through a series of aerobic tests.
Hillman found that children who are in good physical shape respond faster when asked to discriminate between two different images that flash quickly upon the computer screen.
In another study, Hillman looked at the relationship between academic performance and physical activity in third- and fifth-graders. Results from the study showed that active children were more likely to perform better inside the classroom than their less-active classmates.
""The more fit [you are], the better your performance on cognitive tests,"" Hillman said. While most scientists agree that exercise has a positive effect on the brain, scientists continue to search for an explanation as to how exercise changes the brain to improve cognition.
One of the greatest clues as to how exercise affects the brain comes from decades of animal research, said Ronald Kalil, UW-Madison professor of neuroscience. Although scientists once believed that the brain was unable to produce new brain cells following birth, researchers now recognize that at least two regions of the brain generate thousands of new nerve cells daily throughout life by a process known as neurogenesis. Strong evidence also suggests that certain behaviors, such as exercise, lead to an increase in neurogenesis.
According to Kalil, previous animal studies show that exercise leads to increased generation of new nerve cells in the hippocampus, the region of the brain we have largely to thank for the ability to learn, remember and more.
""Neurogenesis in the hippocampus is highly influenced by behavioral circumstances,"" Kalil said. ""A rodent in a cage with access to a running wheel will show a significantly higher number of new nerve cells in the hippocampus than one without.""
Because there are currently no good techniques for studying neurogenesis in humans during our lifetime, scientists continue to closely examine animals to gain a better understanding of neurogenesis. So far, rodent studies have revealed that in addition to exercise, problem solving and social status also lead to increased levels of neurogenesis, while stress and alcohol can reduce levels of neurogenesis.
Animal studies may also help lead researchers to develop new techniques for studying neurogenesis in humans. At Columbia University last spring, a group of scientists zeroed in on a specific region of the brain that appeared to change after a group of inactive adults demonstrated increased memory skills following a 12-week exercise program. The study was also tested in mice, who displayed similar improvements in memory.
Using a functional M.R.I., a machine that allows scientists to monitor brain activity, researchers discovered human and mouse exercisers showed a higher number of new blood vessels to the hippocampus than those who did not exercise. According to Scott Small, Columbia University associate professor of neurology, and senior author of the study, the number of new blood vessels in a region signifies how well an area is functioning.
""Exercise appears to have the greatest effect on a small part of the hippocampus implicated in age-related memory decline,"" Small said. ""If exercise affects memory cells in aging, it gives us hope that we can ameliorate age-related memory decline.""
Additional studies of the mice revealed high levels of new blood vessels correlated with increased levels of neurogenesis, suggesting researchers may be able to use information about new blood vessels, visible by fM.R.I. to measure neurogenesis in humans. In the future, Small said he plans to look for molecular explanations as to how exercise causes neurogenesis and what this means for the brain.
Kalil is also working hard to solve the mystery of the role neurogenesis plays in the brain. In the future, he hopes to determine ways to create and redirect newly generated cells to replace cells damaged by injury or disease.
""In the future, it may be possible for neuroscientists to take advantage of the ongoing neurogenesis that occurs in the brain to redirect newly generated nerve cells to help overcome brain injury,"" Kalil said. ""If this can be accomplished, we open up huge possibilities for future therapeutics.""
""We have the behavioral means to improve our cognitive health across the lifespan,"" Hillman said. ""What's disappointing is that it's not easy to get people to exercise. In fact, we're moving in the wrong direction.""
In the future, Hillman plans to study whether or not exercise intervention can improve the cognitive function of kids. Previous studies in adults have shown exercise intervention works and even small amounts of aerobic exercise improve cognitive performance.
So, how do you get started? Hillman suggests incorporating small changes into your daily routine.
""Take the stairs over the elevator, walk instead of riding a bus, and most importantly, [since] exercise comes in many forms, find something you enjoy and you are likely to stick with it longer,"" Hillman said. ""We have to make time for exercise everyday. It's good for your brain and body.
