Exercising in nature is superior to exercising in the city or at the gymExercise Exercising in green surroundings improves mood, reduces stress levels, and improves heart rate compared to exercising in the city or indoors. This is shown by new research from the University of Copenhagen. The study provides new insights that can be used to improve public health. An hour of brisk walking in the forest, on the beach, or in a green park reduces stress hormones, improves mood, and makes exercise easier to enjoy.