Forest Bathing (Shinrin-yoku)

Japan's practice of immersive forest walking has been studied extensively since the 1980s. Phytoncides — antimicrobial compounds released by trees — measurably boost natural killer cell activity for up to 30 days after a single forest visit. A 2019 meta-analysis of 143 studies found significant reductions in cortisol, heart rate, and blood pressure compared to urban environments. It's not hiking — it's slow, sensory engagement with the forest. And it works.