but is it because they are stronger, or because they have a healthier life in general, filled with more exercise than average? I mean, is the effect the same for 100m runners (=strength) and 10000m runners (=less pure strength)?
They corrected for "age, physical activity, smoking, alcohol intake, body mass index, baseline medical conditions, and family history of cardiovascular disease" and cardiorespiratory fitness.
I don't understand how they do that (never been into statistics); suppose two persons are alike for the above factors, and they do the same amount of training, but one trains for muscle strength and the other to be able to do longer runs. Does this study conclude then that the first one is likely to outlive the second one?
