A new study show that just five minutes in a natural, green environment—rather than an urban one—can improve our mood and self-esteem. "The study shows, for example, that being in a green environment is better than being in an urban one in terms of a measurable positive effect on blood pressure, hormones and stress levels. Intriguingly, it also concludes that the biggest beneficial boost from exposure to nature is gained within the initial five minutes of each encounter with the great outdoors."