What's the Latest Development?

At least once in your life, you have probably had that familiar feeling of fatigue mixed with alertness after exercising. The fatigue is your tired muscles, the alertness is your brain, somehow awakened by physical activity. A recent study carried out in Ireland confirms that exercise improves cognitive performance: After half an hour on a bicycle, individuals did much better on memory tests which associated names with unknown faces. Blood samples were taken in order to look for a biological corollary.

What's the Big Idea?

Scientists believe a greater quantity of a special protein known as brain-derived neurotrophic factor, or BDNF, is released in greater quantities during and after strenuous physical exercise. Individuals who have an especially low output of BDNF have often found it difficult to remember past learned behavior—piloting a jet, in the case of one experiment. "The evidence is very, very strong that physical activity will increase BDNF levels and improve cognitive health," says Dr. Ahmad Salehi, a behavioral scientist at Stanford.