A study found that people who said that they weren't exercising as much as their peers were much more likely to live shorter lives, even if they get plenty of exercise.

People who believe they are not exercising enough are more likely to suffer the consequences of inactivity whether or not they are sedentary, while those who believe they are active are more likely to be healthy even if they aren’t working out, according to new Stanford University research.

Powerful effects of perception

Crum, an assistant professor of psychology,  and Zahrt, a doctoral candidate at the Graduate School of Business, analyzed surveys from more than 60,000 U.S. adults from three national data sets. The surveys documented participants’ levels of physical activity, health and personal background, among other measures. In one of the samples, participants wore an accelerometer to measure their activity over a week.

Zahrt and Crum were interested in one question in particular: “Would you say that you are physically more active, less active, or about as active as other persons your age?”

The researchers then viewed death records from 2011, which was 21 years after the first survey was conducted. Controlling for physical activity and using statistical models that accounted for age, body mass index, chronic illnesses and other factors, they found that individuals who believed that they were less active than others were up to 71 percent more likely to die in the follow-up period than individuals who believed that they were more active than their peers.

How mindsets influence us

Zahrt and Crum offer possible explanations for mindsets and perceptions having such powerful effects on health. One is that perceptions can affect motivation, both positively and negatively. Those who are made aware of their healthy activity levels – like the hotel room attendants in Crum’s 2007 study – can build on them and exercise more. Those who deem themselves unfit are more likely to remain inactive, fueling feelings of fear, stress or depression that negatively affect their health.

The researchers also cite the established influence of placebo effects, where patients who think they are getting a treatment experience physiological changes without receiving actual treatment. In the same way, people who believe they are getting good exercise may experience more physiological benefits from their exercise than those who believe they aren’t getting enough exercise.

“Placebo effects are very robust in medicine. It is only logical to expect that they would play a role in shaping the benefits of behavioral health as well,” Crum said.

The researchers emphasize that the study is correlational in nature and thus does not prove that perceptions of inactivity cause earlier death. However, other experimental research – such as Crum’s 2007 study – does suggest a causal nature to the link between perceived amounts of exercise and health outcomes.

Taking mindsets seriously

“So much effort, notably in public health campaigns, is geared toward motivating people to change their behavior: eat healthier, exercise more and stress less,” Crum said. “But an important variable is being left out of the equation: people’s mindsets about those healthy behaviors.”

In fact, a growing volume of research from Crum and other labs shows that perceptions and mindsets predict health and longevity, for example, in the domains of stress, diet and obesity.

That our mindsets could have such potent effects on our physiology may seem provocative and unlikely at first glance, but Crum reminds us that we shouldn’t be surprised by these results considering the “everyday experiences where our beliefs or a simple thought have very palpable and physiological effects.”

“In the case of stress, a thought about something going wrong can make us sweat or [become] shaky or increase our heart rate,” Crum continued. “With sexual arousal, a simple thought or idea can have immediate physical effects. We experience these things regularly, and yet we’re not cataloguing them as something that matters. For whatever reason – dualism or a prioritization of the material – we tend to ignore the fact that our thoughts, mindsets and expectations are shaping our everyday physiology.”

Source: Stanford University