Medical X-Press – Len Cantor
Working out in a natural environment can also be more physically challenging, making your body work harder and bringing greater fitness results. This happens when, for instance, you’re walking, hiking or running on natural terrain, which can vary in evenness and require more exertion than on a flat surface, such as a treadmill. https://medicalxpress.com/news/2018-12-benefits-outdoors.html