The Mind-Exercise Connection: Part 1

A bike ride or a morning at the gym is good for your muscles (and your waistline), but it turns out that exercise is good for the brain, as well. In recent years, there’s been an explosion of scientific evidence pointing to a powerful connection between physical activity and long-term brain health. In fact, the latest research shows that just 30 minutes of aerobic exercise three to five times a week can lead to significant brain benefits:

Enhanced Memory and Learning – Cognitive abilities normally decline as we age, but numerous studies have shown that more physical activity is associated with better cognitive functioning. For example, one study showed adults older than 55 who had lower levels of cardiovascular fitness had worse global cognitive function, attention and executive function six years later compared to individuals who had higher cardio activity levels (Barnes, et al., 2003). Clearly, it is never too early or too late to start being active!

Better Blood Flow and Oxygen to the Brain – The human brain is less than 2% of body weight, but it uses 15-20% of the body’s blood supply to obtain nourishing oxygen. In his book: “Spark: the Revolutionary New Science of Exercise and the Brain,” John Ratey discusses the many ways that aerobic exercise increases blood flow and oxygen to the brain. For example, exercise generates nitric oxide, a gas that enlarges the blood vessels’ passageways, allowing more blood and oxygen to be pumped into the brain. Contracting muscles releases a fibroblast growth culture (FGF-2), which activates a molecular chain reaction that manufactures the endothelial cells that line blood vessels and are important in building new ones. The more blood vessels in our brain, the more we protect our brain from stroke damage by “creating redundant circulation routes that protect against further blockages.” If blood flow to the brain stops, the brain dies. Makes a set of jumping jacks sound a bit more appealing, doesn’t it?

Improved Mood, Anxiety Relief – Chronic stress takes its toll on the brain, causing physical changes with long-term consequences such as fearfulness, pessimism, moodiness and even depression. But exercise is one proven way to exert control over the physical and emotional feelings of stress.

Exercise literally changes our memory of what stress feels like. The physical manifestations of exercise – quick breathing and a pounding heart – mimic the physical reaction to stress. By exercising, we re-train our brains to associate the physical signs of stress and anxiety with something positive that we control. Habitual aerobic exercise helps the brain perceive the thumping heart not as a sign of an impending panic attack but with walking on a treadmill.

Exercise also affects one’s mood through the release of endorphins and the production of a protein called Brain-Derived Neurotrophic Factor (BDNF). Endorphins, which are stress hormones, are produced by the body and help calm the brain and alleviate muscle pain during exercise. Runners often report feelings of elation, an example of the link we see between the general feeling of well-being and exercise. In the Alameda County Study, researchers followed 8,032 people for over 26 years and questioned them about their lifestyle habits and healthfulness beginning in 1965. They re-surveyed the participants twice more in 1974 and 1983. The results showed that people who had no depression at the beginning of the study and who were inactive for the last nine years of the study were 1.5 times more likely to be depressed than active participants. Additionally, those who were inactive to begin with but increased their level of activity were no more likely to be depressed at the end of the study than were those who were active at the start. (Camacho, T.C., et.al., 1991).

Recent studies have pointed out that exercise increases Brain-Derived Neurotrophic Factor (BDNF), a nerve cell protein which helps support the survival of existing neurons by keeping them functioning and growing, and even spurs the growth of new neuron cells in the brain. Decreased levels of BDNF may contribute to the atrophy of the hippocampus and prefrontal cortex, and has been observed in depressed patients. So a regular jog around the block may contribute to the alleviation of depression, protection against nerve cell death, the stimulation of new brain cell growth and the strengthening of connections between brain cells.

Now that it’s obvious that pumping up actually pumps up your brain, how about some proof that exercise actually makes you smarter? Check out these exciting findings in The Mind-Exercise Connection: Part 2.