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Health, psychology & science stories

 

Art de Vany & evolutionary fitness (New Scientist)

7 June 2013

Published in New Scientist as Yabba Daba Dooo!


ART DE VANY is 62, but physical fitness tests three years ago showed he had the body of a 32-year-old. Although De Vany is sceptical of such assessments, he knows he's in good shape. His former career as a professional baseball player may have something to do with it, but he attributes his physical prowess to an exercise regime inspired by the lifestyle of our Palaeolithic ancestors.

De Vany's advice to the modern exercise freak is to cut duration and frequency, and increase intensity. "Our muscle fibre composition reveals that we are adapted to extreme intensity of effort," says De Vany, a professor of economics at the Institute for Mathematical Behavioral Sciences at the University of California, Irvine. His approach to fitness combines Darwinian thinking with his interest in chaos theory and complex systems.

This new science, which De Vany calls evolutionary fitness, is part of growing efforts to understand how the human body has been shaped by evolution, and to use this knowledge to improve our health and fitness. Proponents believe the key lies in the lifestyle of our hunter-gatherer ancestors because, they say, the vast majority of the human genome is still adapted to an ancient rhythm of life which swung between intense periods of activity and long stretches of inertia.

Across the Palaeolithic - which covers the period between 2.6 million and 10,000 years ago - prey animals were large, fleet of foot, or both. For men, this would have meant lots of walking or jogging to find herds, dramatic sprints, jumps and turns, perhaps violent struggles, and long walks home carrying kill. Women may not have had such intense exercise, but they would have spent many hours walking to sources of water or food, digging up tubers, and carrying children. If modern hunter-gatherers are anything to go by, men may have hunted for up to four days a week and travelled 15 kilometres or more on each trip. Women may have gathered food every two or three days. There would also have been plenty of other regular physical activities for both sexes such as skinning animals and tool making, and probably dancing.

Our ancestors must have evolved cardiovascular, metabolic and thermoregulatory systems capable of sustaining high-level aerobic exertion under the hot African sun, according to Loren Cordain of the Human Performance Laboratory at Colorado State University. And given that the Palaeolithic ended only an evolutionary eye-blink ago, we ignore its legacy at our peril.
Cordain and his colleagues point out that in today's developed societies, inactivity is associated with diseases such as hypertension, diabetes and heart disease. Contemporary hunter-gatherer societies rarely experience these modern killers, they say.

This is where De Vany's exercise ideas come in. "The primary objectives for any exercise and diet programme must be to counter hyperinsulinaemia (chronically elevated insulin) and hypoexertion (wasting of the body's lean mass through inactivity)," he writes in his forthcoming book about evolutionary exercise. Exercise and diet are linked. For example, says De Vany, our appetite
control mechanisms work best when our activity mimics that of our ancestors. But he feels that most modern exercise regimes are not hitting the mark.

De Vany views the body as non-linear and dynamic and says exercise should mix order and chaos - structure and novelty. Too much endurance training is harmful. "Chronic aerobic exercise overtrains the heart, reducing the chaotic variation in heart rate which is essential to health," he says. Likewise, most weight training is governed too much by routine and is too time-consuming. He gives his own workout a chaotic character with ascending weights and descending repetitions. To these brief but intense gym workouts he adds a wide variety of other activities that vary randomly in intensity and duration. These include rollerblading, bicycling, walking, sprinting, tennis, basketball, power walking, hitting softballs and trekking with a grandson on his shoulders.

He also argues that most people do not train the right muscles for that ultimately attractive - and adaptive - quality of symmetry. "Symmetry is a reliable evolutionary clue to health," he says. "Tumours and pathologies produce gross asymmetries, and our love of symmetry reflects the reproductive success of our ancestors, who were sensitive to these clues." He strives for the X-look - a symmetrical balance of mass in the shoulder girdle, upper chest and back, the calves and lower quads, two of the four large muscles at the front of the thighs. This also makes men look taller, he adds, "another reliable evolutionary clue that women use to find good genes".

The hunter-gatherer lifestyle indicates that women should exercise only a little less intensely than men, says De Vany. "Women are opportunistic hunters who go after small game when they come across it. They also climb trees to capture honey and snare birds. And have you ever seen how much work it is to dig out a deep tuber?" Women benefit enormously from strength work, he says. It increases their bone density and they get and stay leaner by building muscle mass. "Today's women are so weak [compared with their female ancestors]."

Of course, people vary. De Vany acknowledges that our ancestors were adapted to a variety of terrains and climates. Cordain points out that genetic differences between populations lead to different physical strengths. East Africans, for example, seem to be better endurance runners, West Africans better sprinters.

But human genetic similarity greatly outweighs the variations. Our genes have changed so very little since Palaeolithic times.


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