Much
has been written about the "caveman," or "Paleolithic," diet. The
basic theory behind it is that while many changes
have occurred in human society over the course of thousands of years,
the human body remains the same as it was
during the Stone Age. According to proponents of Paleolithic nutrition,
most degenerative diseases common today, such as cardiovascular disease,
cancer and diabetes, result from the
introduction of foods incompatible with
human genetics. A less publicized aspect of the Paleolithic concept is
how exercise enters the picture. A recent review discussed the relationship between human genetics and
exercise.1
One relevant point is that
ancient man and woman were far more active
than modern people. Those who lived
in the Paleolithic era not only burned far more calories than we do today, but by necessity they also had to do
things like move heavy loads, which they alternated with getting sufficient rest so they could tackle another day of hard physical labor. The average
ancient human had a physique that
was on the muscular side. The activity level made the occurrence of obesity
extremely unlikely. The problem today is that all humans still harbor
genes that interact with intense physical activity. Paleolithic experts contend that the humans today who most resemble their Paleolithic forbears are champion athletes.
Since the body is designed for
activity, bad things happen when it doesn't
get it regularly.
Studies examining
hunter-gatherer societies that exist today, the so-called primitive peoples living
in places such as Africa and New Guinea, show that cardiovascular disease,
obesity and diabetes simply don't exist there. Yet when those
people do move into a more modern society, they, too, become
prone to the same degenerative diseases.
Sensible
weight training provides many of the benefits of a Paleolithic lifestyle.
Bodybuilding interacts with genetic factors that prevent diseases.
Examples include the upregulation of glucose use in the body by
exercised muscle, which prevents type II diabetes. Another example is
the continued promotion of hormonal activity that would otherwise decline with
age, such as the maintenance of insulinlike growth factor 1 (IGF-1), which
helps to preserve both muscle and connective tissue.
A loss
of muscle with age or disease is now considered a harbinger of
impending death. It's called sarcopenia, and when sufficient muscle is lost,
death is not far off. Most people who live in nursing homes are there
because they have become so weak from loss of muscle that they can no
longer care for themselves. Doctors know that when cancer or AIDS patients lose
lean tissue mass, they often spiral into death. Keeping muscle keeps
people alive.
Cardiovascular
disease is a modern disease that results from a combination of dietary and
lack-of exercise factors. The human heart has-or should have-a function
predicated of an active lifestyle. Exercising regularly produces beneficial
changes that favor cardiovascular fitness,
such as increased production of nitric oxide, a chemical that dilates blood
vessels, preventing high blood pressure
and relieving some of the work of the heart. Hearts that aren't exercised
inevitably fail. The point is that
exercise is a mandatory part of human existence.
Not exercising is a definite hazard to human health, resulting in a host of
degenerative, life-shortening diseases. Perhaps the most interesting aspect of
this is that the human body is geared for intense, regular exercise. It seems that a program that includes judicious
doses of both weight training and aerobics is written in our genes.
1. Booth, FW., et al. (2002). Exercise
and gene expression: physiological regulation of the human genome through
physical activity. J Physiol. 543:399-41