In a fitness-crazed land of spin classes and CrossFit gyms, Octavia Zahrt found it can be tough to feel as though you’re doing enough. “When I was in school in London, I felt really good about my activity. Then I moved to Stanford, and everyone around me seems to be so active and going to the gym every day,” she says. “In the San Francisco Bay Area, it’s like 75 percent of people walk around here wearing exercise clothes all day, every day, all the time, and just looking really fit.”
She wasn’t less active than when she lived in London, Zahrt says, but in comparison she began to feel a bit like a slacker. “I felt unhealthy. I was very stressed about fitting in more exercise,” she says.
And just feeling less fit in comparison to others might trim away years of life, says Zahrt, a Ph.D. candidate in health psychology at the Stanford University Graduate School of Business. That’s the conclusion of a study she co-authored, published Thursday in Health Psychology.
Past studies have suggested that mindsets concerning one’s own health can have physiological consequences. In 2007, Stanford psychologist Alia Crum ran a study on hotel attendants. “These women were getting lots of exercise, but when we asked them they didn’t have the mindset that their work was good exercise,” Crum says.
She gave some of the hotel staff a presentation explaining that their work, which involves heavy lifting and walking, is good exercise, and then tracked them for a month. “The women who started to look at their work as good exercise had improvements in blood pressure and body fat,” she says.
Crum and Zahrt collaborated on the new study, which looks at what might happen decades down the line. They analyzed data from two large national health surveys, the National Health Interview Survey and the National Health and Nutrition Examination Survey. Along with a litany of health metrics including activity, weight and smoking status, these surveys also ask participants to assess how much they believe they exercise compared to others their own age.
“Individuals who thought they were less active than other people their age were more likely to die, regardless of health status, body mass index, and so on,” Crum says.
That was true even though the researchers looked at people who were roughly the same in every way, including how much they actually exercised based on self-report and step-tracking data, obesity and heart health, except for how much they thought they worked out compared to others.