According to one 32,000 person study in the American Journal of Clinical Nutrition (1999), "fit persons with any combination of smoking, elevated blood pressure, or elevated cholesterol level had lower adjusted death rates than low-fit persons with none of these characteristics". The same study found that aerobic fitness had a far more important impact on longevity than obesity did.
Fantastic Voyage, Kurzweil and Grossman, Chapter 22.
What about those who were not smoking, had no elevated blood pressure or elevated cholesterol AND ALSO were fit? I would expect them to be better off compared to both groups mentioned. It's not like one has to choose between smoking and obesity ...
How "fit" or "obese" were the people, and how "elevated" was the blood pressure and cholesterol?
If the study showed that incredibly "fit" people who smoked occasionally and had a sightly elevated blood pressure and/or cholesterol had a "lower adjusted death rate" (what is that, exactly?) than people who sat in front of the computer all day but had none of the above factors, that would be one thing.
If the study showed that slightly "fit" people who smoked heavily and had an extremely elevated blood pressure and/or cholesterol had a "lower adjusted death rate" than people who sat in front of the computer all day but had none of the above factors, that would be something else.
The same could be asked of the fitness vs obesity results. How fit and how obese?
Also, have the results of the study ever been replicated? Or do they conflict with the results of other studies?
The conclusions of the study were strong, and dose-dependent. I.e. casual exercisers did much better than couch potatoes and heavy exercisers did much better than casual exercisers.
The groups were significantly different. The "obese" people in the study had BMIs of over 30. The "very obese" group had BMIs over 35. The "thin" people had BMIs under 25. Similarly, people with diagnosed hyper-tension were compared with those of low-risk blood pressures. A variety of fitness levels were examined, ranging from couch potatoes to daily (but not competitive) runners.
The study found that fitness had a protective effect against each of the other risk factors. In fact, the only other statistically independent predictor of mortality for men and women was smoking.
>Also, have the results of the study ever been replicated?
Yes. There have been a number of very large studies that have produced similar results.
S.N.Blair et al. 1989 "Physical fitness and all-cause mortality" JAMA Nov;262: 2395-2401 (over 13,000 subjects)
I.M.Lee 2003 "Physical activity in women: how much is good enough?" JAMA Sept 10;290(10) 1377-1378
C.D. Lee, S.N.Blair, and A.S. Jackson 1999, "Cardiorespiratory fitness, body composition, and all-cause cardiovascular disease mortality in men." Am J Clin Nutr. Mar;69(3):373-380.
Fantastic Voyage, Kurzweil and Grossman, Chapter 22.