Being Out of Shape Almost as Bad for You as Smoking

Only smoking ranks higher than poor physical fitness as a risk factor for premature death, according to a new Swedish study that followed participants for almost half a century.

“We found that low aerobic capacity in middle-aged men was associated with increased mortality over several decades,” says lead study author Per Ladenvall, MD, PhD, a researcher in the department of molecular and clinical medicine at the University of Gothenburg in Sweden. “The effect of low aerobic capacity, as a measure of fitness, was the strongest predictor for mortality second to smoking.”

Past research has suggested that physical fitness and aerobic capacity can prolong lifespans. Most of those studies followed people for only 10 to 15 years, and some used self-reported questionnaires to measure fitness levels.

This new study, published in the European Journal of Preventive Cardiology, investigated fitness levels and longevity of 792 white men for 45 years, providing a wealth of data. (Further study is needed on women and other racial groups.)

Beginning in 1963, researchers performed baseline measurements, including weight, serum cholesterol, and blood pressure, on a randomly selected group of healthy 50-year-old men in Gothenburg who agreed to be studied for up to 50 years. In 1967, they conducted an ergometer exercise stress test to measure their maximum aerobic capacity, or VO₂ max. Every 10 years, researchers reexamined the participants.

Aerobic capacity is a more objective measure of fitness than subjective self-reporting, and it’s affected by genetics and lifestyle. Both a sedentary lifestyle and obesity are known to lower VO₂, while exercise increases it.

When the study period ended in 2012 and many of the participants were deceased, researchers were not surprised to find that smoking had the greatest impact on longevity. Poor fitness did not lag far behind smoking, however.

“I was somewhat surprised by the strength of the association,” Ladenvall says. “This finding makes me even more convinced that we should encourage people to stay fit.”

The men with the lowest aerobic capacity (2 liters per minute) had a 21 percent higher risk of early death than those with moderate VO₂ (2.26 liters per minute) and a 42 percent higher risk of dying prematurely than the most fit participants (VO₂ of 2.56 liters per minute).

Poor physical fitness was also a greater health risk than high serum-cholesterol or blood-pressure levels, the researchers found.

“In conclusion, a low exercise capacity during a maximum exercise ergometer test in middle-aged men predicted increased mortality risk over more than four decades, adjusted for traditional risk factors [including smoking, high blood pressure, and high serum cholesterol],” the study authors write.

Public health officials have made great efforts to reduce the number of smokers worldwide;the next challenge, notes Ladenvall, is to encourage people to get active and stay fit.

“We should encourage people to stay fit,” he says. “Even though intense physical activity has the best effect to increase fitness, even moderate physical activity can have a positive effect, especially in those with low fitness. Everyday physical activity should be promoted. This can be done in several ways, including infrastructure with walkable neighborhoods, and being able to commute by walking and bicycling.”

Cardio testing can help you lose weight, streamline your workouts, and boost your overall fitness level. Check out “Fitness Testing 1, 2, 3: Cardio Capacity” in our May 2006 issue.