Positive thinking may push a body beyond what we once thought were its physical limits. British researchers discovered that when physically fit men and women gave themselves repeated motivational talks on stationary bikes, they rode 18 percent longer before hitting the point of total exhaustion.

While it's long been known that positivity can help our focus in skill-based sports such as golf or tennis, researchers are just now finding evidence that it can also push bodies past previously measured physical limits. "The mind is wired to remember negative experiences, such as 'Fire burns,' " says Jane Ehrman, a behavioral health specialist at the Cleveland Clinic who was not an author on the study. "When an activity or experience begins to feel uncomfortable, we want to stop. Those who are motivated to achieve a goal can push past the discomfort."