The Authors' Reply - Letter to the Editors

The primary goals of our study were (i) to create current scientific data on the physiological profile of today's world class skier, and (ii) to look retrospectively for pre-seasonal variables potentially important for the athlete's racing performance in the subsequent season. The very successful Austria Ski Team of 1997 to 2000, which won about half of all World Cup (WC) racing events, served as the study population.

Dr. Maffiuletti and colleagues correctly outline the importance of anaerobic capacity for the energy supply in alpine skiing where all racing competitions last between 45 seconds and 2.5 minutes. The anaerobic metabolism meets a substantial part of the immediate energy demands of ski training or competition, causes lactate generation and lactic acidosis by impaired tissue oxygenation leading to altered muscle contraction, coordination and impaired motor dexterity. An improved aerobic capacity delays these unfavourable effects of the anaerobic metabolism and allows the athlete to use his hopefully excellent technical ski abilities harder and longer, improving race time. In addition, a high aerobic capacity is virtually indispensable for a fast and sufficient recovery in the short intervals between the runs or races and for the coping with the overall stress of a long racing season of 4 - 5 months.

Against Dr. Maffiuletti's opinion, there is no general consensus that the anaerobic capacity in alpine skiing is decisive. All papers cited by Dr. Maffiuletti cannot substantiate this assumption. The references quoted primarily reflect the reviewers' opinion (see Dr. Maffiuletti's ref. [[2], [5], [7]]) but are certainly not based on respective original data. The two original papers cited (see Dr. Maffiuletti's ref. [[1], [6]]), published in 1983 and 1991, were strictly descriptive and compared inhomogeneous skier populations of a completely different niveau (international, national and regional skiers) looking for differences in the group classification but not for a coherence between variables of physiology and parameters of racing success.

Dr. Maffiuletti criticises that a consistent correlation between parameters of success and muscle strength or aerobic power could not be found in all subgroups. Of course, we are aware that a consistent correlation in all subgroups would have affirmed the explanatory power of the study, but from our point of view this was not achieved for the following reason. The studied athlete population consisted of the world's best professional skiers characterised by a very high and homogeneous proficiency level. In small selected groups (number of females = 20; number of males = 28), however, a slight diversity among determinants makes it statistically difficult to find significant differences in a kind of sport generally accepted to be multifactorial. We consider, therefore, the homogeneous and high level of muscle strength found in the study to be the most likely explanation for the lacking association between racing performance and strength beyond a certain cut-off value. A lacking correlation, however, cannot neutralise our practical experience that muscle force of the lower limbs is a decisive determinant in alpine skiing. With regard to aerobic power, we found a highly significant correlation between WC ranking position and W_max (r = 0.947; p = 0.001) and V·O_2max (r = 0.964; p < 0.001) in males in the speed group in 1998 (see Fig. [1]). Besides this strong association, many further hardly nonsignificant positive trends between aerobic power and racing performance could be found in both sexes in specialists (technique and speed group) but not in all-rounders.

Fig. 1 Scatter plot of world cup ranking position vs. W_max/kg and V·O_2max in male world dress skiers in 1998. The lines are regression lines (r = 0.947 for W_max, r = 0.964 for V·O_2max) in the speed group.

We agree with Dr. Maffiuletti that professional alpine skiing is a very complex kind of sport. To avoid further misunderstandings, we take the liberty of repeating the study's take-home message that racing performance in alpine skiing depends on several abilities and cannot be predicted from single physiological parameters tested in the laboratory setting. Nevertheless, until scientific counter evidence is brought, we stick to our experience - gained on elite skiers for decades and confirmed by some results of the present study - that good aerobic power is the sports-unspecific basis in alpine skiing on which any further abilities, inter alia anaerobic capacity, should be built.

References

• 1 Brown S L, Wilkinson J G. Characteristics of national, divisional and club male alpine ski racers.  Med Sci Sports Exerc. 1983;  15 491-495
• 2 Hintermaister R A, Hagerman G R. Physiology of alpine skiing. Garrett WE, Kirkendall DT Exercise and Sport Science. Philadelphia; Lippincott Williams and Wilkins 2000: 695-707
• 3 Karlsson J, Eriksson A, Forsberg A, Kallberg L, Tesch P. Physiology of alpine skiing. Park City, UT; The U.S. Ski Coaches Association 1978: 30-41
• 4 Neumayr G, Hoertnagl H, Pfister R, Koller A, Eibl G, Raas E. Physical and physiological factors associated with success in professional alpine skiing.  Int J Sports Med. 2003;  24 571-575
• 5 Tesch P A. Aspects of muscle properties and use in competitive alpine skiing.  Med Sci Sports Exerc. 1995;  27 310-314
• 6 White A T, Johnson S C. Physiological comparison of international, national and regional alpine skiers.  Int J Sports Med. 1991;  12 374-378
• 7 White A T, Johnson S C. Physiological aspects and injury in elite alpine skiers.  Sports Med. 1993;  15 170-178