Physical fitness trumps body weight in reducing death risks

December 5, 2011

even if your body weight has not changed or increased -- you can reduce your risk of death, according to research reported in Circulation: Journal of the American Heart Association.

In a study of 14,345 , mostly white and middle or upper class, researchers found that:

  • Maintaining or improving fitness was associated with a lower even after controlling for (BMI) change.
  • Every unit of increased fitness (measured as MET, metabolic equivalent of task) over six years was associated with a 19 percent lower and stroke-related deaths and a 15 percent lower risk of death from any cause.
  • Becoming less fit was linked to higher death risk, regardless of BMI changes.
  • BMI change was not associated with death risks.
BMI is a measurement based on and height (kg/m2). MET measures the intensity of – specifically, the ratio of metabolic rate during a specific physical activity to a reference rate of metabolic rate at rest.

"This is good news for people who are physically active but can't seem to lose weight," said Duck-chul Lee, Ph.D., the study's lead researcher and physical activity epidemiologist in the Department of Exercise Science at the University of South Carolina's Arnold School of Public Health in Columbia. "You can worry less about your weight as long as you continue to maintain or increase your fitness levels."

Results of the study underscore the importance of physical inactivity as a risk factor for death from heart disease and stroke, said researchers. Researchers also found no association between changes in body fat percentage or body weight and death risk.

Participants, who were an average 44 years old, were part of the long-term, large-scale Aerobics Center Longitudinal Study. They underwent at least two comprehensive medical exams.

Researchers used maximal treadmill tests to estimate physical fitness (maximal METs), and height and weight measurements to calculate BMI. They recorded changes in BMI and physical fitness over six years. After more than 11 years of follow-up, researchers determined the relative risks of dying among men who lost, maintained or gained fitness over six years. They accounted for other factors that can affect outcomes, including BMI change, age, family history of , beginning level, changes in lifestyle factors such as smoking and physical activity, and medical conditions such as high blood pressure or diabetes.

One possible explanation for these results: about 90 percent of the men were either normal weight or overweight at the beginning of the study. Among obese people, changes in BMI might have a significant effect on death risks. So it's unclear whether these results would apply to severely obese people, Lee said.

A BMI score under 25 is considered healthy, 25 to less than 30 is overweight, and 30 or greater is obese.

Because the study was mostly done in white middle and upper class men, it's difficult to know whether the results apply to other racial and socioeconomic groups. Women would likely have similar results as the men in the study, Lee said.

Explore further: Obesity and large waist size linked to higher risk of death in African-American women

Related Stories

Obesity and large waist size linked to higher risk of death in African-American women

September 7, 2011
The risk of death increases with higher levels of overweight and obesity among African American women, according to a new study led by researchers from the Slone Epidemiology Center at Boston University. In addition, a larger ...

Recommended for you

Five vascular diseases linked to one common genetic variant

July 27, 2017
Genome-wide association studies have implicated a common genetic variant in chromosome 6p24 in coronary artery disease, as well as four other vascular diseases: migraine headache, cervical artery dissection, fibromuscular ...

Could aggressive blood pressure treatments lead to kidney damage?

July 18, 2017
Aggressive combination treatments for high blood pressure that are intended to protect the kidneys may actually be damaging the organs, new research from the University of Virginia School of Medicine suggests.

Quantifying effectiveness of treatment for irregular heartbeat

July 17, 2017
In a small proof-of-concept study, researchers at Johns Hopkins report a complex mathematical method to measure electrical communications within the heart can successfully predict the effectiveness of catheter ablation, the ...

Concerns over side effects of statins stopping stroke survivors taking medication

July 17, 2017
Negative media coverage of the side effects associated with taking statins, and patients' own experiences of taking the drugs, are among the reasons cited by stroke survivors and their carers for stopping taking potentially ...

Study discovers anticoagulant drugs are being prescribed against safety advice

July 17, 2017
A study by researchers at the University of Birmingham has shown that GPs are prescribing anticoagulants to patients with an irregular heartbeat against official safety advice.

Protein may protect against heart attack

July 14, 2017
DDK3 could be used as a new therapy to stop the build-up of fatty material inside the arteries

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.