EatQOD

Interesting discussion - while caloric restriction appears to prolong maximal lifespan in rats, exercise does not. Most (all?) of this work has been done by a tremendous researcher, John Holloszy. His work was covered in Life Extension magazine.

Here is a link to an article in LE describing Holloszy's work:

http://72.14.203.104/search?q=cache:vAV ... =clnk&cd=2

The article was a review describing an Ageing conference in 2001 - so it's not new, but I couldn't find any more recent work in this area:

Here is an excerpt:

"Exercise prevents pathology, but does not extend maximum life span

The anti-aging benefits of exercise were a major topic at the conference. Gerontologists agree that exercise plays a starring role when it comes to the extension of health span. But, like nutrition, exercise seems to give rise to various quasi-religious dogmas about which type and amount of exercise is best, and what exercise actually accomplishes, especially in terms of longevity. It was refreshing to have Joseph Holloszy, M.D., of Washington University School of Medicine, a pioneer in exploring the impact of exercise on aging, present some solid research data based on his animal studies.

The first of Holloszy's presentations was devoted to the importance of exercise in preventing abdominal obesity and insulin resistance. His overall conclusion is that while exercise can extend average life span, it does not extend maximum life span (the longest life span in a group of animals). Exercise, however, can dramatically affect "secondary aging"-the incidence and severity of diseases associated with aging. It is the aging-related degenerative diseases that often reduce individual life span, or at least "health span." To put it in simple terms, exercise appears to help prevent disease and extend the number of healthy years in old age, an extremely important benefit.

Exercise helps prevent abdominal obesity; at the very least, it reduces the degree of abdominal obesity. Abdominal obesity is the number one cause of secondary aging, according to Holloszy. It is a very reliable marker of insulin resistance in humans and animals. In the rat model, a fattening diet (either a high-fat or a high-sucrose diet) leads to bdominal obesity and insulin resistance. The question of whether abdominal fat actually causes insulin resistance remains unsettled. Since an excess of either dietary fat or dietary sucrose leads to abdominal obesity and insulin resistance, one could argue that it's a matter of excess calories. There is also the view that chronically elevated insulin levels (caused by the wrong diet and lack of exercise) lead to both insulin resistance, due to the downregulation of the insulin receptor, and to abdominal obesity. What is not in doubt is that a large waist circumference indicates insulin resistance, and a dramatically elevated risk of all the degenerative disorders in which excess insulin is known to play a part."

Looks like a very interesting magazine, Life Extension.

Their website is http://www.lef.org.

JT