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In this 2004-03-10 article, Dean presents and discusses a study from several years ago showing that from a mortality perspective "fat & fit" beats "thin & unfit". This would seem reason enough to motivate CRONies to exercise.

Someone wrote:

> How fat was "fat"? How lean was "lean"?

[...] I went back in my
personal archives and found the reference (and free full text!) of the "fit
& fat beats thin and unfit" we've discussed in the past [1]. I think the
details you are looking for are in the full text.

What follows is the commentary I provided on 7/29/02 during the discussion
of [1] in a thread called "fit & fat beats thin and unfit":
--------------------

Another CRONie noted:
> I agree and was hoping someone might critique the study,
> since it obviously runs contrary to key assumptions about CR,
> especially the view that being thin and doing little exercise
> might be the path to maximum longevity. The study in question
> was very large, with around 22,000 subjects over 8 years. It
> concludes that there was no morality reduction attributable
> to thinness per se, only to cardio-respiratory fitness.
>
> PMID: 10075319
> http://www.ncbi.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubM
> ed&list_uids=1
> 0075319&dopt=Abstract

I've never bought into the idea that sedentary CRON is the way to go to
maximize benefits. This study seems like at least *weak* support for this
personal belief. Looking at the full text, the results were really quite
striking. Here is a quote:

"Unfit men in the lowest quartile of waist girth had 4.9 times (P < 0.001)
the risk of all-cause mortality of their peers who were fit. In contrast,
fit men in the highest quartile of waist girth had no elevated risk of
all-cause mortality and had much lower mortality risk than unfit men in the
lowest quartile of waist girth."

Put more bluntly, the unfit skinny men (lowest waist circumference) had
*twice* the risk of all-cause mortality of *any other category* including
unfit men with the highest girth. Among fit individuals, risk of all-cause
mortality was virtually independent of waist girth.

More generally, eyeballing the graphs in the paper, it appears that the
relative risk of all-cause mortality (in decreasing order) was:

* Obese & unfit - most deaths
* Lean & unfit
* Normal & unfit
* Obese & fit
* Lean & fit
* Normal & fit

For Cardiovascular Disease mortality, the order was similar, but slightly
different. Basically, for risk of CVD death, being fit was most important,
and once you were fit, having less fat meant less risk of death:

* Obese & unfit - most deaths
* Normal & unfit
* Lean & unfit
* Obese & fit
* Normal & fit
* Lean & fit

One possible explanation (besides the obvious one - that exercise conveys
tremendous health benefits) for this dramatic result could obviously be that
the unfit men were unfit because of some preexisting health condition. Here
is what the author's said on the subject:

"The possibility of bias due to baseline health status is a consideration in
all observational studies, including this one, but we think that serious
bias is unlikely in this case because all study participants were given
extensive medical examinations at baseline, which enabled us to exclude
those with a history of myocardial infarction, stroke, or cancer. In
addition, men who failed to achieve 85% of their age-predicted maximal heart
rate on the maximal exercise test were excluded; this should have eliminated
men who did not have a history of disease but were not feeling well as a
result of an undiagnosed condition. We also adjusted the analyses for
presence or absence of an abnormal electrocardiogram result. This exclusion
eliminated men with angina, arrhythmia, or electrocardiographic
abnormalities on the treadmill test, as well as resting electrocardiographic
abnormalities. The effect of all these exclusion criteria was to minimize
the possible bias of baseline subclinical disease."

Another potential explanation is that these results don't apply to CRonies,
since there is no (direct) evidence that the lean individuals were CR'ed in
any way relative to their own "setpoint" or relative to the fatter subjects
in the study. Similarly, the diet of the vast majority of all participants
in this study was likely woefully inadequate - as it is with most Americans.
Again, may not apply to CRonies.

But then again, the evidence seems to suggest that CR'ed organisms die from
the same causes in approximately the same proportions as AL-fed organisms,
just at a later age. So anything we CRonies can do to prevent the common
killers, like CVD, is a good thing. If this study is any indication,
maintaining physical fitness may be far-and-away the best thing we can do in
this regard (other than CR - maybe).

No question in my mind - I'm sticking with my (moderate) exercise regime.

-Dean

-------------
[1] Am J Clin Nutr. 1999 Mar;69(3):373-80

Cardiorespiratory fitness, body composition, and all-cause and
cardiovascular disease mortality in men.

Lee CD, Blair SN, Jackson AS.

Free full text:

http://www.ajcn.org/cgi/content/full/69/3/373

BACKGROUND: Cardiorespiratory fitness and body fatness are both related to
health, but their interrelation to all-cause and cardiovascular disease
(CVD) mortality is unknown. OBJECTIVE: We examined the health benefits of
leanness and the hazards of obesity while simultaneously considering
cardiorespiratory fitness. DESIGN: This was an observational cohort study.
We followed 21925 men, aged 30-83 y, who had a body-composition assessment
and a maximal treadmill exercise test. There were 428 deaths (144 from CVD,
143 from cancer, and 141 from other causes) in an average of 8 y of
follow-up (176742 man-years). RESULTS: After adjustment for age, examination
year, cigarette smoking, alcohol intake, and parental history of ischemic
heart disease, unfit (low cardiorespiratory fitness as determined by maximal
exercise testing), lean men had double the risk of all-cause mortality of
fit, lean men (relative risk: 2.07; 95% CI: 1.16, 3.69; P = 0.01). Unfit,
lean men also had a higher risk of all-cause and CVD mortality than did men
who were fit and obese. We observed similar results for fat and fat-free
mass in relation to mortality. Unfit men had a higher risk of all-cause and
CVD mortality than did fit men in all fat and fat-free mass categories.
Similarly, unfit men with low waist girths (<87 cm) had greater risk of
all-cause mortality than did fit men with high waist girths (> or =99 cm).
CONCLUSIONS: The health benefits of leanness are limited to fit men, and
being fit may reduce the hazards of obesity.

PMID: 10075319