A study by Brandon Irwin assistant professor of kinesiology at the Kansas State University says that those who exercise with a friend post better workout time and intensity by as much as 200 percent. He and his colleagues tested whether individuals engage in more intense physical activity when alone or with a virtual partner or while competing against a team mate. ‘People like to exercise with others and make it a social activity. We found that when you're performing with someone who you perceive as little better than you you tend to give more effort than you normally would alone’