Imagine a few dozen female housekeepers from seven hotels participating in a study aimed at measuring how the mind affects physical fitness and health. One group continued their daily routine after being physically examined and told that their workday provides enough exercise to meet the requirements for a healthy, active lifestyle. The control group was told nothing. Four weeks into the study, researchers reassessed the women’s health.

Surprisingly, the study found that the women in the informed group had lost an average of two pounds, lowered their blood pressure by almost 10 percent, and appeared healthier in terms of body mass index and waist-to-hip ratio. The housekeepers in the control group, on the other hand, did not show the same positive changes. Researchers concluded that health is significantly affected by mind-set, and that the mind plays an important role when it comes to both realizing health and treating disease. 

Source: Association for Psychological Science, 2007