What are those conditions? Gage's and other scientists' studies confirm that your middle-aged brain's hippocampus can create new brain cells when you

• engage in a physical routine regularly such as swimming, yoga, bicycling, or racquetball
• that involves repetition
• that is practiced with intention and attention
• and that gets your heart beating faster.

Regularity. Repetition. Attention & Intention. Pulsing Heart. Gage cannot yet explain the mechanism for why these conditions grow new neurons. But they do.