This study showed a relation between “strenuous” physical activity as reported by participants and cognition two years later. Strenuous activities walking, bicycling, swimming, gardening, “or other exercise,” so the types of physical activity were diverse. The inclusion of walking and gardening in the definition of physical activity suggests that even moderate activity may be useful in helping older adults avoid cognitive decline. Persons who said they did some form of activity three times a week were classified as “moderately active” while those who were active more frequently were classified in a “high activity” group.

The bottom line: Another study shows that even moderate activity may help prevent cognitive decline as people age.

Reference:

Etgen T et al. (2010). Physical activity and incident cognitive impairment in elderly persons: The INVADE study. Archives of Internal Medicine, 170, 186-193. Free full text is available at the journal website.

A recent study in the Archives of Internal Medicine shows that strength training can improve executive functions. Executive functions are important because they are a mental ability that helps us make decisions and do several things at once (like driving). Executive functions get worse as we get older, so finding a way to maintain or improve them may be a way to keep your brain fit as you get older. This study evaluated the effects of resistance training compared to balance and tone training on older women’s abilities on several cognitive measures. The researchers evaluated whether weight training (generally thought to improve muscular strength) or balance training (thought to improve balance, but also such things as walking ability and risk of falls) also had an effect on participants’ mental functioning.

Compared to the balance and toning group, the strength training group showed small but significant gains in their performance on the Stroop Test. The Stroop measures a person’s ability to deal with conflicting stimuli – someone’s tendency to read a word (a habit) compared to their ability to resist the habit and say the color of the type used to print the word. Performance on this measure is often interpreted as an aspect of executive functions, a group of mental abilities that includes such things as coordinating two mental activities at once (think about driving).

The study only included older women (average age about 70 years), so it’s not clear how strength training would affect younger persons’ or men’s functioning. On the other hand, the study adds to the growing body of research that shows that strength training may be important for  maintaining your brain fitness.

Reference:

Liu-Ambrose T et al. Resistance training and executive functions. Archives of Internal Medicine, 170, 170-178.

The mice who ran performed much better on several tasks that required that they tell the difference between two visual patterns.The effect of running was very clear in adult mice. In mice who were very old, though, running didn’t make much difference, and they didn’t get much boost from the exercise.

John Grohol at PsychCentral also posted about the article, noting that some newspaper accounts barely mentioned the fact that the study was done with mice. He even points out that it was done with a specific variety of mice, and suggests that the relevance of the study may be limited. It’s true that it is very hard to know whether studies about mice really mean much for humans, since findings in animals often don’t generalize to humans.

As Grohol notes, the research is pretty clear that exercise can improve cognitive functioning in people as well as animals.But I’m not as concerned as he is that the results of this study will only apply to one strain of mice. Animal research has its problems when we apply it to human research, but in this case studies in humans have consistently shown similar results to those in animals. It may still be true that the reasons for changes in cognitive function in humans and animals may be different, but that means we would have to come up with two separate mechanisms for change. That’s actually making the situation more, rather than less, complex.

Dr Grohol makes an excellent point about human and animal research. Too often, we jump from preliminary findings to the real world. In areas in which animal and human studies generally agree,though, animals studies can extend and help find new directions for research at considerably less cost than similar studies in humans.

Reference:

Creer DJ et al. Running enhances spatial pattern separation in mice. Proceedings of the National Academy of Sciences, published online first January 19,2010 doi:10.1073/pnas.0911725107

A recent study in the Archives of Neurology shows that muscle strength is related to risk for Alzheimer’s disease. In a group of persons with an average age of 80 years, those with the greatest muscle strength had the lowest chance of developing Alzheimer’s over up to six years. About one in five of the people with the lowest muscle strength (the lowest 10%) developed Alzheimer’s disease over the study follow up, while fewer than one in ten of those with the greatest strength (the highest 10%) developed Alzheimer’s in the same time – about half the risk.

Does this mean that weight training will keep you from getting Alzheimer’s or other memory problems? It’s not clear. Endurance training has been shown to increase brain-derived neurotrophic growth factor (BDNF), a substance that facilitates the growth of new nerve cells in the brain. This increase in BDNF may be part of the reason why exercise improves cognition. But a recent study of weight training with middle-aged men and women didn’t show any change in BDNF with weight training.

Given the association of mood, cognition, and loss of muscle tissue in frailty (see another blog post about frailty here), though, maintaining muscle mass through weight training may be an important way to maintain and improve physical and cognitive functioning.

References:

Boyle PA, et al. (2009). Association of muscle strength with the risk of Alzheimer disease and rate of cognitive decline in community-dwelling older persons. Archives of Neurology, 66, 1339-1344.

Levinger I, et al. (2008). BDNF, metabolic risk factors, and resistance training in middle-aged individuals. Medicine and Science in Sports and Exercise, 40, 535-541.

I think one of the biggest challenges for many people in changing or maintaining a change in their fitness program is focus. When you’re managing a complex project at work, a social life, maybe worrying about getting the kids to  school play on time, and who knows what else, it’s easy to let other things slide. Sometimes it’s just basic prioritizing, but sometimes it’s because you can’t focus.

If you want to stick with a brain training program  during the season, do something to help you focus on what you want to accomplish every day, and include brain training:

• Take a few moments every morning to review your daily to-do list before beginning the day.
• Set a reminder in your cell phone or computer calendar that will pop up every day.
• Put your daily to-do list on a 3 x 5 card and post it on your refrigerator or on a mirror in your dressing area.

The key idea is not to make your brain have to remember things in a time when your life is most complicated. Figure out a way to off load some of the memory tasks to your cell phone, computer, or environment.