Numerous studies have shown that people move less skillfully and learn motor tasks more slowly when they are required to focus their attention on their body. A few of these experiments have involved running. A 2009 study by German researchers, for example, found that runners were less economical when thinking about the movements of their body as they ran than they were when focusing on their breathing, and were less economical when focused on their breathing than they were when they paid attention to the environment around them.
