I honestly don't think that there is enough conclusive evidence to say either way. The general population is a pretty bad measure to compare (think of the SAD and all of the rampant obesity). I feel like any change in exercise would prove to be beneficial when measured against the general population. I think there's too many other factors that would skew the data.

A better study would be to follow two populations with controlled diet (paleo is great for this) starting at the same age and to see the difference in longevity between endurance athletes and power athletes, following up every couple of years. Of course, this study would take decades to complete, and it would be impossible to control the level of exercise, among other confounding factors.

The only other option that may come close is an animal study, but even that would be only an approximation. So I guess the best we could truly do is try to understand the physiology of exercise and what endurance or power actually does to our core components. Your own body is also a great source of evidence. If it makes you feel amazing and it doesn't burn/tire you out or have negative side effects, then it's probably good for you as an individual.

I like Colpo alot but he is dead wrong. I have no idea what data he is sourcing because over all endurance athletes die a lot earlier. Take a look at this study that has all the professional sports teams i work with really re evaluating what they are asking them to do.

J Appl Physiol. 2011 Feb 17. Diverse patterns of myocardial fibrosis in lifelong, veteran endurance athletes. Wilson MG, O'Hanlon R, Prasad S, Deighan A, Macmillan P, Oxborough D, Godfrey RJ, Smith G, Maceira A, Sharma S, George KP, Whyte G.

1ASPETAR- Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.

http://www.ncbi.nlm.nih.gov/pubmed/21330616

Abstract

Aims - This study examined the cardiac structure and function of a unique cohort of documented life-long, competitive endurance veteran athletes (> 50 years). Methods and Results - Twelve lifelong veteran male endurance athletes (mean ± SD [range] age: 56 ± 6 yr [50-67]), 20 age-matched veteran controls (60 ± 5 y; [52 - 69]) and 17 younger male endurance athletes (31 ± 5 years [26-40]) without significant co-morbidities underwent cardiac magnetic resonance (CMR) imaging to assess cardiac morphology and function, with CMR imaging with late gadolinium enhancement (LGE) to assess myocardial fibrosis.

Results - Lifelong veteran athletes had smaller LV and RV end-diastolic and end-systolic volumes (p0.05), but was significantly associated with the number of years spent training (p50 miles) marathons (p

Conclusion - An unexpectedly high prevalence (50%) of myocardial fibrosis was observed in healthy, asymptomatic life-long veteran male athletes, compared to zero cases in age-matched veteran controls and young athletes. This data suggests a link between life-long endurance exercise and myocardial fibrosis that requires further investigation.

Read more from the MESO-Rx Steroid Forum at: http://forum.mesomorphosis.com/mens-health-forum/when-exercise-too-much-134303829.html#ixzz1Mu6dCYmO

  J Appl Physiol (February 17, 2011)Diverse patterns of myocardial fibrosis in  

lifelong, veteran endurance athletes Wilson, M.1, O’Hanlon, R.2,3, Prasad, S.2, Deighan, A.4, MacMillan, P.5, Oxborough, D.6, Godfrey, R.7, Smith, G.2, Maceira, A.8, Sharma, S.9, George, K.10 and Whyte, 4

They compared age cohorts of those who did life long endurance training and those who did regular exercise. 100% of the endurance athletes had myocardial fibrosis. 0% in the other group. I can tell you this one paper has all athletes and trainers rethinking their ideas on how to train. It also explains why cardiac death is the number one reason that endurance athletes die.....and cancer is two.

This is will be a focus for me to write about. I think its critical that this paper get read by every paleo athlete. I hand it out to all my patients who fit the bill.

Edit: by Dexter to show study.

Endurance running and the like was discussed here:

http://paleohacks.com/questions/37979/does-strenuous-endurance-exercise-induces-hormonal-and-other-changes-which-might#axzz1Mou8mEOr

And here:

http://paleohacks.com/questions/33826/do-you-aspire-to-be-an-elite-runner#axzz1MovhPUEQ

this study is only about correllations. it is kind of like taking a survey of americans and concluding that those who eat highly processed tofu products from wholefoods have less disease than the general population. not persuaded that there is causation here.

These are broad correlational studies and don't say much. Again, what's your benchmark. Longevity is relative because we're all gonna die some day. Better longevity compared to whom? If you say the average American, well, then, the average endurance athlete is in much better shape than someone who mindlessly follows the standard American diet, who is obese, near diabetic and eats food toxins with impunity these days.

Think about it. An elite endurance athlete who keeps in shape, probably eats well (though carb-heavy), burns all he eats, and is in running shape is miles ahead of the average American. Now, you compare that athlete to a sample of BMI-fit low carbers or Paleo followers who exercise moderately, but not for endurance. Then you can make a point based on these results.

Some of these tests are not worth the paper they're printed on. But do take note that it is hard to design a rigorous test that will screen such variables and keep a pure sample of low carbers. You have to go by their words.

There is a built-in bias in all these studies. Elite athletes are by definition more fit, have more endurance, more atheletic, and more coordinated than the general population. What does this imply: they probably have lower FBG, lower BP, lower pulse, more fit cardiovascularly, and free from autoimmunity than the general population. At least when they were athletes, since they would have expended whatever they took in - so what they ate a carb-heavy diet. It is highly probably, though, that such athletes, especially ednurance athletes, stuck to an active lifestyle after their career and probabe ate a better diet. Would a general population?

By comparing elite athletes to any sample in the general population, you're getting a biased result. Of course, they would be more fit. And they're expected to live longer than the general pop. But would they had they not stuck to their endurance fitness regimen? That is the relevant question, not the idiocy that Colpo has cooked up.

It's like comparing a group of people with IQs of 150 to those with 90. Which group is more likely to have finished high school education? Which group is likely to have higher-paying jobs? The results are self-evident and tests like these are designed to be self-fulfilling and confirm prejudices, not true hypotheses.