98 ■ FLOW
a different challenge to be resolved with a choice of the most efficient
foothold that will give the best leverage, simultaneously taking into
account the momentum and the center of gravity of the body and the
various surfaces—dirt, rocks, roots, grass, branches—on which the foot
can land. On a difficult trail an experienced hiker walks with economy
of motion and lightness, and the constant adjustment of her steps to the
terrain reveals a highly sophisticated process of selecting the best solu
tion to a changing series of complex equations involving mass, velocity,
and friction. Of course these calculations are usually automatic, and give
the impression of being entirely intuitive, almost instinctive; but if the
walker does not process the right information about the terrain, and
fails to make the appropriate adjustments in her gait, she will stumble
or will soon grow tired. So while this kind of walking might be entirely
unselfconscious, it is in fact a highly intense activity that requires con
centrated attention.
In the city the terrain itself is not challenging, but there are other
opportunities for developing skills. The social stimulation of the crowds,
the historical and architectural references of the urban milieu can add
enormous variety to a walk. There are store windows to see, people to
observe, patterns of human interaction to reflect on. Some walkers
specialize in choosing the shortest routes, others the most interesting
ones; some pride themselves in walking the same route with chronomet-
ric precision, others like to mix and match their itinerary. In winter
some aim to walk as long as possible on the sunny stretches of the
sidewalk, and to walk as much in the shade as possible in the summer.
There are those who time their crossings exactly for when the traffic
lights change to green. Of course these chances for enjoyment must be
cultivated; they don’t just happen automatically to those who do not
control their itinerary. Unless one sets goals and develops skills, walking
is just featureless drudgery.
Walking is the most trivial physical activity imaginable, yet it can
be profoundly enjoyable if a person sets goals and takes control of the
process. On the other hand, the hundreds of sophisticated forms of
sport and body culture currently available—ranging from racquetball to
Yoga, from bicycling to martial arts—may not be enjoyable at all if one
approaches them with the attitude that one must take part in them
because they are fashionable, or simply because they are good for one’s
health. Many people get caught up in a treadmill of physical activity over
which they end up having little control, feeling duty bound to exercise
but not having any fun doing it. They have made the usual mistake of
confounding form and substance, and assume that concrete actions and