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Alpine skiing
Sport, at a top level, usually requires massive physiological adaptation. For example, cross-country skiers and marathon runners develop huge maximal oxygen carrying capacity, as a result of extensive training. It has been recognised that the very best international ski racers do not exhibit unique physiological characteristics common to such groups as marathon runners (Bacharach & Duvillard 1995). There have been several reports on the aerobic power of alpine skiers; Values for maximal oxygen consumption (VO2 max) for competitive alpine ski racers shows huge variation (Haymes & Dickerson 1980). They recorded the U.S. male ski team’s average VO² max to be (66.6 ml/kg/min). One of the highest recorded values for an alpine ski racer was (70ml/kg/min) recorded by (Eriksson, Nygaard & Saltin, 1977). This result measured in an elite athlete, may reflect the training programme of the athletes and not the actual demands of the sport (Karlson 1984). The majority of competitions occur at altitudes between 2500- 3500m, consequently adequate aerobic power is needed. A high aerobic capacity increases the ability to recover from repeated bouts of anaerobic exercise, and allows the athlete to sustain aerobic work for a longer duration (Song 1982).
Haymes & Dickinson, (1980) found that the greatest performance-forecasting factor in the U.S. (Male & Female) ski team was leg strength.
Brown and Wilkinson, (1983) used isokinetic dynamometers to examine Force-Velocity relationship of different athletes. Male alpine skiers demonstrated increased strength preferentially at slow concentric speed.
Rusko, Havu & Karvinen, (1978) showed that the percentage slow twitch (ST) fibre distribution of alpine skiers is higher (63% ± 8 SD ST in Vastus lateralis,) than in ordinary reference subjects (47 % ± 13 SD ST). More recently, Tesch (1995) stated that alpine skiers do not posses a distinct fibre type composition; Skiers tend to show a preponderance of slow twitch fibres.
During skiing there is a high rate of glycogen utilisation that eventually may result in depletion of muscle glycogen stores by the end of a day of intense skiing (Tesch 1995) The nature of the slalom event means that it is of high intensity and relatively short duration and therefore relies heavily on the ATP / PCr energy system.
The glycolytic contribution in the slalom and giant slalom events is about 40% of the total energy cost. Following a race, blood lactate concentration averages (9-13 mmol/L). A muscle lactate concentration of 24 mmol/kg wet muscle tissue has been reported. (Andersen & Montgomery, 1988)
Elite skiers have higher lactate values than advanced or novice skiers. The aerobic demands of competitive Alpine skiing may approach (90 to 95%) of the athlete's maximal aerobic power. Maximal heart rate is achieved during the latter part of the race. (Andersen et al. 1988)
It is generally accepted the a development of fatigue during maximal short duration exercise is associated with the depletion of muscle PCr stores (Hultman, Greenhaff, Ren, & Söderlund 1991)
A study on intermediate recreational skiers by Weiland, DeVoe & Gatshall (1998) showed that energy expenditure ranged from 6.2±2.0 kcal/min to 11.3±2.5 kcal/min depending on slope difficulty. This suggests that high energy expenditure occurs while participating in alpine skiing.
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Linear Mode
