86Thousand400: The Underlying Connection

We learned in the early 1990s that Brain Derived Neurotrophic Factor (BDNF) protects neurons against cortisol in areas that control mood, including the hippocampus.

Extremely high levels of cortisol can decrease BDNF, however exercise directly increases BDNF. BDNF is the rope in a tug of war between chronic stress and adaptability. The Miracle Gro molecule became the new serotonin.

In postmortem studies of people with depression who died of suicide, their brains showed significantly decreased levels of BDNF. Even in healthy people, low BDNF levels have been correlated with personality traits that make them more vulnerable to depression, such as neuroticism and hostility.

One study showed that combining exercise with antidepressants spiked BDNF by 250%. And in humans, we know that exercise raises BDNF, at least in the bloodstream, much like antidepressants do.

Today, research focuses on BDNF as well as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF-2), insulin like growth factor (IGF-1), and all the related chemicals involved in encouraging neuroplasticity and neurogenesis.

BDNF turns on genes to produce more neurotransmitters and neurotrophins, puts the brakes on self-destructive cellular activity, releases antioxidants, and provides the proteins used as building material for axons and dendrites.

Exercise clearly elevates BDNF. What makes aerobic exercise so powerful is that it's our evolutionary method of generating that spark. It lights a fire on every level of your brain, from stoking up the neurons' metabolic furnaces to forging the structures that transmit information from one synapse to the next. Exercise also immediately improves the highest form of thinking.

The beauty of exercise is that it gets us moving, naturally, which stimulates the brain stem and gives us more energy, passion, interest, and motivation. We feel more vigorous.

Exercise shifts our self-concept by adjusting the chemicals serotonin, dopamine, norepinephrine, BDNF, VEGF, and so on. (Without exercise all these sit placid). And unlike many antidepressants, exercise doesn't selectively influence anything - it adjusts the chemistry of the entire brain to restore normal signaling.

It frees up the prefrontal cortex so we can remember the good things and break out of the pessimistic patterns of depression