Four studies of Oppezzo & Schwartz ( 2014 ) suggests that walking, on average, increases creativity by 60 %. This increase occurs while walking and shortly after. It is the activity of walking that makes the difference and not the surroundings. Therefore, it also helps to walk indoors ( e.g. on a treadmill ), and not only in natural landscapes. It is said that e.g. Steve Jobs and Mark Zuckerberg have meetings on their feet, so it might not be a bad idea. Other studies suggest that physical activity also has anti-depressive effect and helps against some types of anxiety (generalized anxiety disorder, agoraphobia and panic disorder).