Survival of the Fittest: Part 3 by Fred Dimenna, CSCS

An organism adapts to the stresses placed on it and evolves accordingly soley for the survival of the species. Human beings have evolved to require daily physical exercise. Unfortunately, technological advancement has removed much of the physical stress that was an integral part of daily life and the survival of the human species.

Because humans typically become less active as they age, it is difficult to separate the effects of reduced physical stimulation from those of the passage of years, per se. One interesting change that takes place as we get older is a shift towards a greater reliance on muscle fibers that function without oxygen (anaerobically). These are the players that should be called into action when we work at very high levels of exertion (when sprinting or lifting heavy weights, for example), but not during moderate challenges. Use of these fibers disrupts internal equilibrium and dramatically reduces our ability to tolerate work.

A loss of oxidative capacity as we age is at the root of the shift toward anaerobic reliance. Our cardiovascular system is responsible for delivering oxygenated blood to body tissue and its ability to perform decreases as the years pass. If it is not regularly challenged, oxygen delivery is seriously compromised and this causes a detrimental cascade effect. Our tissues contain enzymes that allow oxygen to be effectively used and so the aging process rapidly progresses when these enzymes can no longer perform their function.

As the human organism is currently configured, the vast majority (approximately 85%) of its energy requirement is satisfied by oxygen dependent (aerobic) energy turnover. But this wasn't always the case. When "life" (self-replicating molecules) first appeared on this planet, the atmosphere was completely devoid of oxygen. Consequently, anaerobic metabolism was the sole mechanism on which living creatures relied and the byproduct of this form of energy transfer (oxygen) began to build up. This "waste" gas posed a threat, so organisms evolved that actually used it to dispose of electrons that were stripped from ingested fuels. And the aerobic energy system was born!

Developing the capacity to use oxygen as a metabolic accomplice was a critical adaptation that facilitated our survival and is responsible for life as we know it. Without an aerobic energy system, we would be relegated to a very limited physical presence here on Earth. If you consider the activity levels of patients afflicted with cardiovascular and pulmonary diseases that impair tissue oxygen provision, you'll catch my drift. But the aerobic system must be maintained to ensure it continues to operate at peak capacity. And just because we use it most of the time doesn't mean that requirement is being met. The stimulation involved in daily living simply isn't enough, especially when that amount of stimulation ain't what it used to be!

By evolving technologically, we have upset the natural balance that existed between what was required to maintain our physical capacity and the physical outlay our daily regimen presented. But this need not be the case. One cannot doubt that technology has saved us countless hours every day: After all, visiting the supermarket an hour each week is a heck of a lot less time consuming than hunting down dinner each night. What have we done with this "extra" time? Your guess is as good as mine, but it has to be around somewhere. And if we invest a small fraction of it into subjecting our body to programmed physical stress (exercise) on a regular basis, we can reap the myriad benefits that technology allows while dodging its drawbacks.

A few months back, I wrote about Jean Blaydes Madigan, a highly acclaimed researcher who has extensively studied brain theory. The take home message from her work is simple: There is a link between physical activity and learning. Considered in conjunction with the rising tendency for inactivity in the adult population and the trickle down effect this behavior has on our youth, it doesn't bode well for the future. In fact, if she is correct, the very commodity that is responsible for the technological advancements we've made (our intellect) may wind up the victim of the "progress" it has begot.

My cat is 18 years old, has failing kidneys and suffers from arthritis. Nevertheless, when I look outside, I see her walking about. I feed her everyday, so her purpose is not to find food. It is simply instinctual. For some reason, humans have developed a propensity for inactivity that is antithetical to this natural drive. And this learned tendency has been reinforced by the reduced call for physical activity that daily life provides.

Exercise is the critical link that will allow us to prosper from technological advancement, instead of succumbing to it. Aerobic exercise keeps your cardiovascular system functioning at the top of its game. And resistance training makes your muscles stronger, thereby reducing the amount of stress associated with all of the daily activities you perform. Collectively, these endeavors help you evolve physically. And if you challenge yourself these ways on a regular basis, your own personal survival will be ensured.

Fred Dimenna, a Certified Strength and Conditioning Specialist and lifestyle and Weight Management Consultant is a two-time Natural Mr. United States and a WNBF drug-free professional bodybuilder. Visit him at or email him: