THROUGH the cigar-filled haze of a Victorian drawing room, the time traveller
begins his story. He tells of the year 802701 AD, when humans have degenerated
into two races. The Eloi are elfin, beautiful and graceful, but indescribably
frail on account of their life of splendid idleness. The wormish Morlocks are
banished to a life of labour underground.
This is our future according to H. G. Wells鈥檚 The Time Machine,
first published in 1895. Could Wells possibly have envisaged that the sloth
induced by late 20th-century technology would bring us so rapidly to a
punctuation mark in human evolution? For Wells鈥檚 dimorphism is already starting
to emerge. Faced with a life of increasing inactivity, how we choose to behave
will have profound implications for the destiny of the species.
Over the past 50 years, the environmental pressure on humans, especially the
affluent, has changed more rapidly than at any time in history. And with the
increasingly rapid market penetration of every new labour-saving device, the
pace of change gets ever faster. If this seems an exaggeration, compare your own
life with that of your grandparents.
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Manual labour has virtually disappeared as hydraulic diggers replace shovels
and robots dominate production lines. Power tools have taken the sweat out of
home improvements, while people have traded in their bicycles for cars. Power
steering, electric windows and central locking spare every ounce of effort, and
because mobile phone users don鈥檛 need to find a phone box, they are saved from
walking an estimated 16 kilometres a year.
The resulting reduction in muscular effort has an enormous effect on energy
turnover. At the pinnacle of human endurance, Antarctic explorers, Nordic skiers
and Tour de France cyclists expend 300 per cent more than their basal metabolic
rate (BMR)鈥攖hat鈥檚 the energy they鈥檇 use up lying around all day and not
eating. At the lower end, 鈥淗omo sedentarius鈥� expends only 40 per cent more than
its BMR. In the middle, African villagers living a traditional subsistence
lifestyle use between 100 and 120 per cent more energy than their BMR. The
Africans, then, do up to three times as much physical activity as slothful
Westerners. The difference amounts to between 500 and 700 kilocalories a
day鈥攅nough energy to walk 17 kilometres or to run 10.
There are four competing reasons to buy labour-saving devices: to save
labour, to save time, to do jobs better and to keep up with the Joneses. While
the last may be triggered by pride and envy, only the first directly implies the
sin of sloth. But the second is the one to really watch.
Great seduction
For some people, saving time allows them to be immensely productive and enjoy
more active leisure. These are the slim, bronzed Californians of the lifestyle
adverts鈥攊f not fictitious, then at least rare. In contrast, a very high
proportion of us succumb to the greatest seduction of the modern
age鈥攖elevision. The average Briton spends 28 hours a week glued to the TV.
In the US, it鈥檚 38 hours. If a Martian scanned English homes at 8.45 pm, it
would find no less than 48 per cent of the population sitting in front of a
glimmering box.
This is sloth indeed, and is already bringing a smile to the face of the grim
reaper. Not only will we have to account for our sins at the gates of heaven,
but some of us will have to do it sooner than we think if we don鈥檛 wake up to
the insidious effects of sloth on health. Obesity is the most obvious result
(though sloth must vie with gluttony to take the credit). In the past 15 years,
the number of obese people in Britain has more than doubled. A quarter of
middle-aged people are classified as clinically obese and three-quarters are
overweight. The US is farther down the line. In some groups, such as black,
Hispanic and middle American women, clinical obesity exceeds 50 per cent.
A person whose weight reaches 254 kilograms (40 stones or 560 pounds) may be
carrying some 2 million kilocalories stored as fat. Lugging around this huge
accumulation of unused energy causes severe health problems, such as joint
disorders and back pain, sleep apnoea, which stops you breathing at night, and
sexual dysfunction. And sloth鈥檚 miseries do not stop there.
Inactivity leads to loss of cardiac fitness, which raises the risk of heart
disease and the likelihood of death when a heart attack does strike. Muscle
wasting is now thought to be a major contributor to adult-onset diabetes.
Muscles are important 鈥渆nd users鈥� of glucose, and essentially the less muscle
you have, the more sugar is left in the blood, leading to hyperglycaemia.
Certain cancers, depression and many other diseases are now linked to sedentary
lifestyles. The incidence of osteoporosis increases with inactivity; like
saplings in the wind, bones are strengthened by the regular pull of muscles.
It is only in recent years that we have started to appreciate this link
between sloth and ill-health. Our metabolic physiology evolved over aeons of
hunter-gathering and subsistence farming, a world in which diet was marginal
and vigorous activity a feature of everyday life. Yet this is not today鈥檚
world.
So what of H. G. Wells鈥檚 future race? How will we now evolve? Wells predicted
that 鈥渇rail light limbs and fragile features鈥� would become the norm because,
when physical exertion is no longer needed, 鈥渨hat we should call the weak are as
well equipped as the strong鈥�. He deftly side-stepped the issue of whether
leanness or obesity is the appropriate adaptation to a life of idleness by
having his Eloi eat nothing but fruit.
Without this fictional constraint, we can already observe (especially in the
US) the emergence of a bimodal distribution of body shape鈥攖he waifs and
the whales. The waifs are those who have realised that our weight-regulating
physiological drives have been overwhelmed by modern living. To compensate, they
have imposed their own cognitive control by dieting, power-walking to the office
or doing aerobics.
In the battle between waifs and whales, the odds are against the whales.
Obesity not only damages health but also leads to economic and social
disadvantage. Of course, many of these harmful effects occur after reproductive
age, which militates against the obesity trait being bred out of us. So it鈥檚 by
no means certain that the thin will inherit the Earth.
There is an exquisite irony in this tale. To save themselves from the ravages
of sloth, humans may turn again to the technology that made them idle in the
first place. For those too lazy to exercise, there are devices such as the New
Ultratone Futura. Electric pulses from this 鈥渦ltimate body shaper鈥� will ensure
that 鈥�100 per cent of your muscle fibre is being trained鈥�. This supposes, of
course, that you can be bothered to strap on the electrodes.
