Here is question 18 of 25 from Brain Fitness 101: Answers to Your Top 25 Questions.

Question:
Is physical fitness important to your brain fitness?

Key Points:

• Exercise improves learning through increased blood supply and growth hormones.
• Exercise is an anti-depressant by reducing stress and promoting neurogenesis.
• Exercise protects the brain from damage and disease, as well as speeding the recovery.
• Exercise benefits you the most when you start young.

Answer:

Yes. According to Fred Gage, PhD, of the Salk Institute for Biological Studies, “We now know that exercise helps generate new brain cells, even in the aging brain.”

According to the research of Richard Smeyne, PhD at Saint Jude Children’s Research Hospital in Memphis, with just two months of exercise there are more brain cells and that higher levels of exercise were significantly more beneficial than lower amounts, although any exercise was better than none. He also found that starting an exercise program early in life to be an effective way to lower the risk of developing Parkinson’s disease later in life.

As little as three hours a week of brisk walking has been shown to halt, and even reverse, the brain shrinkage that starts in a person’s 40s, especially in the regions responsible for memory and higher cognition. The exercise increased the brain’s volume of gray matter (actual neurons) and white matter (connections between neurons).

Increased blood flow to the brain triggers biochemical changes that spur the production of new brain neurons. Brain exercise then protects these fledgling neurons by bathing them in nerve growth factor and forming functional connections with neighboring neurons.

Dr. Kramer said “After only three months, the people who exercised had the brain volumes of people three years younger. This is the first time anyone has shown that exercise increases brain volume in the elderly. It suggests that aerobic exercise can stave off neural decline, and even roll back some normal age-related deterioration of brain structure.”

Further Reading

• How to Keep Your Aging Brain Fit: Aerobics by Sharon Begley, Wall Street Journal, Nov. 16, 2006.
• Buff and Brainy: Exercising the Body can Benefit the Mind by Christen Brownlee, Science News, Feb. 25, 2006;169(8):122.
• Colcombe SJ, Erickson KI, Raz N, Webb AG, Cohen NJ, McAuley E, Kramer AF. Aerobic fitness reduces brain tissue loss in aging humans. J Gerontol A Biol Sci Med Sci. 2003;58:176-80.
• Cotman CW, Berchtold NC. Exercise: a behavioral intervention to enhance brain health and plasticity. Trends Neurosci. 2002;25:295-301.
• Ding Q, Vaynman S, Souda P, Whitelegge JP, Gomez-Pinilla F. Exercise affects energy metabolism and neural plasticity-related proteins in the hippocampus as revealed by proteomic analysis. Eur J Neurosci. 2006;24:1265-76.
• Heyn P, Abreu BC, Ottenbacher KJ. The effects of exercise training on elderly persons with cognitive impairment and dementia: a meta-analysis. Arch Phys Med Rehabil. 2004;85:1694-704.
• van Praag H, Shubert T, Zhao C, Gage FH. Exercise enhances learning and hippocampal neurogenesis in aged mice. J Neurosci. 2005;25:8680-5.
• Vaynman S, Gomez-Pinilla F. Revenge of the “sit”: how lifestyle impacts neuronal and cognitive health through molecular systems that interface energy metabolism with neuronal plasticity. J Neurosci Res. 2006;84:699-715.