"Physical fitness is not only one of the most important keys to a healthy body; it is the basis of dynamic and creative intellectual activity."   —John F. Kennedy

"To keep the body in good health is a duty... otherwise we shall not be able to keep our mind strong and clear."  —Buddha

The "Keeping Fit" column in an October 2009 Press discussed the effects of physical exercise on cognitive abilities. At that time most researchers were looking at aerobic activities like walking and running, which compared favorably to slower paced activities like stretching. In the past year and a half, more research has been done on different populations and on the effects of different types of exercise on mental functioning, with interesting results.

Much of the previous research dealt with two distinct populations: school-age children and older adults. In both cases, aerobic exercise has been found to improve cognitive function. Typically, the end points looked at for students were scores on standardized tests, and, in study after study, it was shown that kids who participated in aerobic exercise prior to test-taking did significantly better than those who did not. In older adults, studies looked at how a group of people who walked 45 minutes a day, three days per week performed on tests of mental acuity as compared to sedentary people. At the end of the trial, the active older folks were much better able to perform basic mental functions, like staying on task, and had better working memory than did the sedentary ones.

In 2010 a group of scientists in Michigan made a big splash by reporting the results of a study that correlated improved grade-point averages (GPAs) of college students with vigorous exercise. They analyzed the activity levels and academic performance of students, adjusting for factors like socioeconomic background, major field of study, and gender. They found that students who participated in at least 20 minutes of vigorous activity at least five days per week had, on average, a GPA 0.4 points higher than students who did not exercise at all, or did so only moderately. These results were presented at the annual meeting of the American College of Sports Medicine in June.

Many reports indicate that aerobic exercise offers cognitive benefits, while weight lifting and stretching exercises do not, but more recent studies suggest otherwise. One study, presented at the 2010 meeting of the Society for Neuroscience, showed that resistance training also has beneficial effects on brain function. Researchers increased the resistance of the wheels available to some of their laboratory rats. The extra resistance would be akin to a human dialing up the resistance on a stationary bike. Laboratory rats are usually kept in cages with wheels, because running is a natural and pleasant activity for these creatures. The rats' running was completely voluntary. They found that the total time the animals spent running decreased when resistance was added, but the overall work performed increased substantially. Rats that ran on either low- or high-resistance wheels had increased levels of brain-derived neurotrophic factor (BDNF) in their blood compared to sedentary controls, which was expected. However, these researchers showed that the amount of BDNF increased as a function of the actual work performed, suggesting that shorter, more intense workouts may offer an even better benefit on brain function than longer, moderate aerobic exercise. BDNF is well known to play an important role in regulating memory, learning and mood in humans.

A study in Florida looked at the effects of weight training on college-aged men. They, too, found that resistance training led to a demonstrable increase in BDNF circulating in their blood after each workout. A study involving women living in a senior community concluded that those who did a regimen of weight lifting only once or twice per week showed marked improvements in cognitive function as compared to those who participated in light stretching exercises. The particular endpoints looked at were things that are well known to deteriorate with age, such as executive functioning skills, decision making, conflict resolution, and staying on task.

The bottom line seems to be that most types of exercise are good not only for your body, but for your mind as well.

For more fitness information visit http://sitzmarkfitness.health.officelive.com.