WHEN it comes to walking off those millennial excesses, a lengthy hike once a
day will do you far more good than nipping down to the shops every couple of
hours鈥攅ven if the short walks add up to the same amount of time, say
exercise researchers in Britain. But walks of any length beat sitting at home
with your feet up and watching television, they stress.
Steve Bird and his colleagues in the department of sport and exercise science
at Canterbury Christ Church University College in Kent reached these conclusions
after putting 56 couch potatoes through an 18-week course of daily walks.
They found that longer walks produce the most beneficial changes to the
composition of blood fats, but walks of any length improve the fitness of the
heart. 鈥淚t鈥檚 the sort of thing that can make the heart 10 years younger,鈥� says
Bird.
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The Canterbury team wanted to find out if people get the health benefits of a
long walk by doing the same amount of exercise in short bursts. 鈥淭his is the
form of walking that fits most easily into people鈥檚 busy lifestyles,鈥� says Bird.
It might include short walks between work and a railway station, plus a walk at
lunchtime.
To find out, Bird divided his normally inactive subjects into three roughly
equal groups. The 鈥渓ong walkers鈥� took a hike of between 20 and 40 minutes every
day. 鈥淚ntermediate walkers鈥� had two bouts of 10 to 15 minutes, and 鈥渟hort
walkers鈥� did three stints of 5 to 10 minutes. The controls sat at home, as
usual.
At the start and end of the 18 weeks, Bird measured the health and fitness of
each group. He found that the long walkers were healthiest, as measured by
altered fat profiles in their blood.
At the end, each litre of blood from the long walkers contained on average
0.05 grams less apolipoprotein II, a 鈥渂ad鈥� fat that is linked with heart
disease. This was more than twice the drop seen in the intermediate walkers, and
five times that in short walkers. In the controls, the level of this fat stayed
the same. The drop in apolipoprotein II in the long walkers was matched by a
rise in the blood level of apolipoprotein I, a 鈥済ood鈥� fat that is associated
with unclogged arteries.
All the walkers showed significant drops in low-density lipoprotein, another
harmful blood fat, although the intermediate walkers came out marginally better
this time. Bird says that all the observed alterations in blood fats are
beneficial, reducing the risks of coronary heart disease, stroke and
osteoporosis.
There was less to choose between the three walking groups when it came to
fitness, as measured by reductions in heart rate and decreases in blood lactate,
which causes fatigue. But all three groups showed marked benefits compared with
the controls. Bird hopes the results will persuade more people to exercise. 鈥淭ry
and do a long walk every day, and even if you can鈥檛, see if you can fit in short
bursts of walking,鈥� he says. 鈥淚t鈥檚 about getting bums off seats.鈥�