NUTRITION IN SPORT

(Martin Jones) #1
Introduction

Recreational touring and racing skiing are
common activities in many countries today but
cross-country skiing has been practised for
several thousand years in northern countries.
Ski-racing equipment has changed considerably,
and the dimensions of the ski have changed from
being 3 m long, 10 cm wide, and weighing 2–3 kg
at the beginning of this century to 2 m, 4 cm and
about 0.5 kg in the modern era. There are special-
ized skis for classic and free-style ski racing. The
courses on which competition takes place have
changed as well. Now grooming machines are
used at least for the more advanced levels of
competition, which makes the tracks very hard
and durable, thus making the conditions more
equal for all competitors. It must be emphasized
that racing conditions vary due to changes in
snow and weather conditions.
Skiing competitions are classified into two
different styles: classic skiing and free style.
Three main techniques are used in classic skiing:
double pole, kick double pole, and diagonal. In
free-style events, skating techniques dominate:
these are characterized by leg movements similar
to those in ice-skating combined with various
forms of double poling.
Elite skiing competitions are performed
over distances ranging from 5 to 90 km. In the
Olympic Games and the world championships,
the distances range from 5 to 30 km in female
events and from 10 to 50 km for males. Relay
races are 4¥5 km and 4¥10 km for women and


men, respectively. At present, individual races
last 12–90 min for women and 22–140 min for
men.
Modern rules stipulate that the courses for
international races must in length be equally
divided into uphill, downhill, and level skiing.
Since the racing speed differs greatly among
these three parts of the course, the time spent in
uphill skiing is more than half of the total racing
time, while downhill skiing time correspond-
ingly occupies less than 10%. Even so, downhill
skiing ability is important. A fall in a downhill
part causes loss of speed and rhythm in skiing.
Compared to the winner, the time ‘lost’ is great-
est in uphill and level skiing. The exact relation
between time spent in the different parts is, of
course, dependent on many factors such as level
of competition and type of terrain.

Characteristics of elite skiers

International elite competitors are often rela-
tively old—average ages are reported to be 27
and 29 years for females and males, respectively,
indicating that it takes years of training to
achieve that level of performance. These elite
athletes do not differ very much in body size,
body weight and appearance from other non-
obese persons, having relatively little body fat
but not to the extreme degree observed in some
endurance sports.
The leg muscles of elite cross-country skiers
have been found to consist of predominantly
slow-twitch fibres but the variability is consider-

Chapter 51


Cross-country Skiing


BJORN EKBLOM AND ULF BERGH

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