If you go to the gym, don't forget to work your placebos

According new study reported in the WSJ:

The mere belief that you are getting a workout affects physiology much as the workout itself does. That is, exercise may affect health in part through the placebo effect: You believe you are doing your body good, and that belief leads to some of the well-documented benefits of exercise.

A group of hotel workers were told that their cleaning work was a fitness routine while a control group was told nothing. The first group "lost an average of two pounds, saw their systolic blood pressure (the first number) drop 10%, lost about 0.5% of their body fat, and reduced their body-mass index by .35 of a point." The control group showed no such changes.

What does this mind-over-body observation tell us? Plenty.

As with everything, attitude matters. Believing you are accomplishing something is an important factor in actually accomplishing it. It appears that science is once again proving that "going through the motions" is a flawed strategy.

It also shows the "power of the placebo", which the article notes is showing up in all kinds of other studies:

A 1998 analysis of 2,318 clinical trials of antidepressants, for instance, showed that half of the therapeutic responses came from the placebo effect: Believing that the pill would relieve depression caused it to do so. (This is why the placebo effect drives drug companies crazy: A drug has to be really good to come out better than the placebo.)

The power of the mind also shows up in conditions that involve the immune system. Exposing people to what they thought was poison ivy caused them to develop a real rash, a 1998 study found, and giving people what they thought was a caffeinated drink (but was decaf) raised their heart rates just as real caffeine does. The mere sight of a doctor can raise blood pressure.

So how what might the power of positive thinking be doing to the body to affect the weight loss?

By believing that you are working out may reduce stress. This would lower blood pressure. The researchers noted that the weight loss is harder to explain but it may reflect a rise in the women's baseline metabolic rate.