Hundreds of studies have linked spending time outside to better health outcomes like decreases in incidences of diabetes and cardio-vascular mortality, lower blood pressure and heart rate, and better immune system function. In fact, these positive effects that are so well-documented that more and more doctors are issuing 'nature prescriptions' to help treat a range of conditions from heart disease, hypertension, high cholesterol, and diabetes, to chronic stress, depression and anxiety, insomnia and even PTSD.
Forbes