The 4'th best way to exercise your brain.
Meditate .
"I wish I could say that meditation and intensive prayer were number one, because that's where our research has been focused. However when it comes to enhancing spiritual experiences, it certainly takes first place. If you stay in a contemplative state for twenty minutes to an hour, (practicing tai chi) your experiences will tend to feel more real, affecting your nervous system in ways that enhance physical and emotional health. Antistress hormones and neurochemicals are released throughout the body, as well as pleasure-enhancing and depression-decreasing neurotransmitters like dopamine and serotonin. Even ten to fifteen minutes of meditation (tai chi) seem to have significantly positive effects on cognition, relaxation, ans psychological health, and it has been shown to reduce smoking and binge-drinking behavior.