How to Live Longer: Stop Thinking You're an Inactive Slacker—it Can Kill You

Everybody loves a slacker. In Clueless, Travis Birkenstock, an adorable skateboarding stoner, attracts Tai, the new girl. In My So-Called Life, Angela Chase falls for Jordan Catalano, a hunky musician who can't quite keep up in school. Wayne's World, which chronicles two delinquent music fans as they try to cash in on a cult-ish local access show, was so beloved it became the highest grossing of the movies based on Saturday Night Live skits.

While being a slacker may have paid off in 1990s rom-coms and TV shows, new research shows that self-professed slackers may die earlier.

Men and women who believe they're less active than their peers may be more likely to die younger than those who simply think they're more active—even if their activity levels are equal, according to a new study published in Health Psychology.

Doctors tell us to exercise regularly, and for good reason: Around the world, 1 in 10 deaths is related to lack of physical activity, according to a 2012 study by Harvard researcher Dr. I-Min Lee. Despite a slew of recent health campaigns to get kids and adults moving, 79 percent of American adults still do not exercise enough. Now, two Stanford University scholars found that people who perceived themselves to be less active than others their age were 71 percent more likely to die during the study's follow-up period than people who believed they were more active.

"Most people know that not exercising enough is bad for your health," Octavia Zahrt, a doctoral candidate at the Stanford University Graduate School of Business, said in a press statement. "But most people do not know that thinking you are not exercising enough can also harm your health."

Zahrt and her co-author, Alia Crum, an assistant professor of psychology, analyzed data from three nationally representative samples, totalling 61,141 U.S. adults. Participants were asked to assess their general health on a scale of 1 to 5 (excellent to poor), and answer questions about their activity level. Some wore a fitness tracker for one week to track their real-time physical activity, and others were asked to note their recent activities and keep track of details like frequency and intensity. After adjusting for factors such as age, gender, race, education, employment, disability, mental health and household income, the study's findings stayed the same: Individuals who perceived they were less active than others still were more likely to die earlier.

People's impressions of their own activity level can be affected by everything from where they live to who they hang out with. "For example, if you live in an area where most of your peers are really fit, you might perceive yourself as relatively inactive, even though your exercise may be sufficient," Zahrt said. "Or if you believe that only running or working out at the gym count as real exercise, you may overlook the exercise you are getting at work or at home cleaning and carrying kids around."

If exercise is so critical to our health, how do we explain the powerful role of these perceptions? The study suggests that people who believe they're living an active lifestyle often make healthier choices. Meanwhile, people who believe they're out of shape compared with their peers are less likely to exercise a year later. Second, people's fears or negative feelings towards their own perceived lack of activity can lead to less physical activity, even depression. A woman who works as a waitress may not think she's getting a lot of exercise (even though she's walking and climbing stairs throughout her shift), and that belief leads to fewer physiological benefits.

Jeff Spicoli and David Wooderson ruled in the '80s and '90s, but today, pop culture is all about overachievers, from Mark Zuckerberg in Social Network to Brian Cooper in Limitless to Frank Underwood in House of Cards. Maybe Hollywood knows something we don't.