Do you get more exercise than the average person? If you answered yes to that question, you are likely in better health. Even if it isn't actually true.

Surprising new research led by Alia Crum, who heads the Mind & Body Lab at Stanford, shows that people's beliefs about their exercise levels have a measurable effect on their health, with those who believe they're getting lots of exercise showing physical effects that match that belief.
It all began with a study Crum conducted in which she and her team interviewed 84 female hotel housekeepers. They asked the housekeepers how much exercise they got. Most of them didn't have gym memberships or anything like that, so their answers amounted to: "not much." However, the very nature of their jobs meant that they were getting the recommended minimum 30 minutes of exercise every day. Crum and her team explained this to half the housekeepers, but not the other half.
A month later, there were some distinct differences between the two groups. Those who were told they'd been getting the recommended amount of exercise reported that they were getting more exercise than before, even though that wasn't objectively true. Amazingly, their bodies were responding as though their exercise level had indeed increased: They had lost both weight and body fat, and their blood pressure had decreased.

The physical benefits of exercise belief

Crum wondered if this was a more widespread phenomenon, so she and her team decided to dig into the National Health Interview Survey and the National Health and Nutrition Examination Survey, both conducted by the federal government in 1990 and 1999, respectively. More than 61,000 Americans participated in the surveys, answering questions about how much they exercised. Many also wore accelerometers that tracked their actual physical activity. The feds followed up with participants in both studies through 2011, which means they were tracked for up to 21 years after their initial surveys.

The results were stunning, and they mirrored what Crum had seen with the hotel housekeepers. People who described themselves as not getting much exercise were 71 percent likelier to die during the follow-up period than those who said they got lots of exercise, whether or not that assessment was accurate. This finding held true even when adjusting for "covariates" such as smoking, chronic illness, and family history of disease.

The finding "suggests that perceptions about health behaviors may play an important role in shaping health outcomes," according to the study's authors. They don't say exactly why believing that you're fit makes you more fit, and without further study it's impossible to know for sure. But there are several possible explanations:

1. The placebo effect

The placebo effect is the reason for double-blind studies and the need to give some participants in medical research fake pills, or placebos. People's tendency to have pain or illness actually improve when given any kind of pill, even one containing no medicine at all, is well documented. Clearly, our belief that we're doing something to improve our health actually can improve our health.

2. A positive attitude

Research shows that people with a generally positive attitude live longer than those with a negative one. So it could be that people who claim to be exercising lots are simply looking at their own lives and habits with the same sunny outlook that they have about everything else.

3. A different identity

Some experts say that you are more likely to become who you believe yourself to be. So if you believe you're someone who takes care of your health and gets lots of exercise, you will tend to behave like someone who takes care of your health and gets lots of exercise. To do otherwise would cause cognitive dissonance, which is a notoriously uncomfortable mental state. Most of our unhealthy habits result from looking for some form of comfort, whether spending the evening stretched out on the couch in front of the TV or eating food that we find yummy and satisfying even though we know it's bad for us. If those activities cause mental discomfort, we're less likely to choose them.
We may never know, or not for a long time, exactly why believing you get lots of exercise improves your actual health. For now, the important thing is to understand that it does. So next time someone asks you if you get lots of exercise, the correct response is to say, "You bet I do!" and to believe it with all your heart. Your heart will benefit, and so will the rest of your body. (Via Inc)