According to psychologists, running is the best way to relieve tension; it boosts serotonin levels, releases endorphins (the happiness hormone) and burns calories and stress. Barcelona-based ad agency Villarrosàs created a campaign for Nike to encourage the young people of Madrid, a particularly stressful city, to get out and run as an antidote to the problems that beset their age group. Each execution in the campaign, launched in Madrid’s underground, has a dual action indicating the problem (a young person in a stressful situation) and its solution (having fun while running). All the situations are explained through oppposing headlines and end with the tagline, “If something's burning you up, burn it off by running.”