Exercising outdoors increases vitamin D and testosterone from sunlight, improves mitochondrial function from infrared light, and reduces nervous system stress from full-spectrum light.

“You're getting ultraviolet light from the sun, which has actually been connected with more vitamin D and more testosterone. You're getting infrared light from being outdoors, which improves mitochondrial function. Melatonin in all of your mitochondria come from infrared light. You're getting full spectrum light without the enriched blue like you get indoors. And the light outside is not flickering. That's stressful for our nervous system.”