A new study supports a belief that many people assume is true: You are more likely to live longer if you have remained physically and mentally fit.
But there are complications. The research, which looked at an overwhelmingly white group of people, suggests that simply feeling positive about life will not boost your life span, while avoiding high stress could give you extra years. In addition, people get the best boost from being both physically fit and low on anxiety.
Although further research is still needed, our results suggest that being fit and finding ways to reduce distress are related to better health and longer lifespan, said study lead author Francisco B. Ortega, a physiology researcher with the Karolinska Institute in Sweden and the University of Granada in Spain.
Previous studies have linked physical fitness and well-being to longer life spans. In the new study, published online and in the November issue of the American Journal of Preventive Medicine, researchers tried to better understand how both work together to affect life span.
The researchers looked at a U.S. study of 4,888 people first examined between 1988 and 1997 and then followed for an average of 15 years.
Of the participants, 98 percent were white and most were well educated and worked as executives or other professionals. The majority 80 percent were male, and ages ranged from 20 to 81.
The researchers adjusted their statistics that factors like body weight would not throw off the results.
The results suggest that people with low levels of distress have a 34 percent lower risk of dying prematurely compared to those with higher levels of distress, Ortega said. Likewise, people with high levels of fitness have a 46 percent lower risk of death than those with a low fitness level.
The researchers did not determine how many years earlier a person would die, on average, if he or she were not physically or mentally fit. Overall, 212 people 4.3 percent died during the study period.
The researchers could not find a link between high levels of positive feelings and longer life spans, but negative well-being definitely had a connection to shorter life spans. This is unusual, Ortega said, because other studies have shown that people live longer when they have a positive outlook.
The study results do not impress Felicia A. Huppert, director of the Well-being Institute at the University of Cambridge in the UK. It does not add much because of the relatively small number of deaths and some other odd findings, she said, For one thing, she said, the study findings are unusual because they suggest that age and gender did not affect the likelihood of death.
The study received funding support from the U.S. National Institutes of Health, the Coca-Cola Company, the Robert Wood Johnson Foundation, the Swedish Council for Working Life and Social Research and the Swedish Heart-Lung Foundation.
Explore further: Tobacco firms get partial win over claims on smoking effects (Update)
More information: Ortega F, et al. Psychological well-being, cardiorespiratory fitness, and long-term survival. Am J Prev Med 39(5), 2010.