Search Results

You are looking at 1 - 4 of 4 items for

  • Author: Michael Vogt x
Clear All Modify Search
Restricted access

Tatiane Gorski, Thomas Rosser, Hans Hoppeler and Michael Vogt

Purpose:

To verify whether relative age effects (RAEs) occur among young male and female Swiss Alpine skiers of different age groups and performance levels. In addition, the efficacy of normalizing performance in physical tests to height and body mass to attenuate RAEs eventually present was tested.

Methods:

The Swiss Ski Power Test consists of anthropometric measures and physical tests for coordination and speed, endurance, and strength and has been used since 2004 to evaluate 11- to 19-y-old Swiss competitive Alpine skiers. The authors analyzed the distribution of 6996 tests performed by 1438 male and 1031 female Alpine skiers between 2004 and 2011 according to the athletes’ respective relative age quartiles. Differences in anthropometric measures and performance in physical tests according to quartile were assessed, and the possibility of attenuating eventual RAEs on performance by normalization of results to height and body mass was tested.

Results:

RAEs were found among all female and male age groups, with no differences between age groups. While performance level did not affect RAE for male skiers, it influenced RAE among female skiers. RAEs also influenced results in all physical tests except upper-limb strength. Normalization of results to body mass attenuated most RAEs identified.

Conclusion:

Small RAEs are present among young Swiss competitive Alpine skiers and should be taken into account in training and selection settings to prevent the waste of possible future talents. When ranking junior athletes according to their performance in physical tests, normalization of results to body mass decreases the bias caused by RAEs.

Restricted access

Micah Gross, Kathrin Bieri, Hans Hoppeler, Barbara Norman and Michael Vogt

Introduction:

Supplementation with beta-alanine may have positive effects on severe-intensity, intermittent, and isometric strength-endurance performance. These could be advantageous for competitive alpine skiers, whose races last 45 to 150 s, require metabolic power above the aerobic maximum, and involve isometric muscle work. Further, beta-alanine supplementation affects the muscle force-frequency relationship, which could influence explosiveness. We explored the effects of beta-alanine on explosive jump performance, severe exercise energy metabolism, and severe-intensity ski-like performance.

Methods:

Nine male elite alpine skiers consumed 4.8 g/d beta-alanine or placebo for 5 weeks in a double-blind fashion. Before and after, they performed countermovement jumps (CMJ), a 90-s cycling bout at 110% VO2max (CLT), and a maximal 90-s box jump test (BJ90).

Results:

Beta-alanine improved maximal (+7 ± 3%, d = 0.9) and mean CMJ power (+7 ± 2%, d = 0.7), tended to reduce oxygen deficit (-3 ± 8%, p = .06) and lactate accumulation (-12 ± 31%) and enhance aerobic energy contribution (+1.3 ± 2.9%, p = .07) in the CLT, and improved performance in the last third of BJ90 (+7 ± 4%, p = .02). These effects were not observed with placebo.

Conclusions:

Beta-alanine supplementation improved explosive and repeated jump performance in elite alpine skiers. Enhanced muscle contractility could possibly explain improved explosive and repeated jump performance. Increased aerobic energy production could possibly help explain repeated jump performance as well.

Restricted access

Tatiane Gorski, Thomas Rosser, Hans Hoppeler and Michael Vogt

Purpose:

To describe the development of anthropometric and physical characteristics of young Swiss alpine skiers between 2004 and 2011, to compare them between age and performance-level groups, and to identify age- and sex-dependent reference values for the tests performed.

Methods:

The Swiss-Ski Power Test includes anthropometric measures and physical tests for coordination and speed, strength, anaerobic capacity, and endurance. The authors analyzed the results of 8176 tests performed by 1579 male and 1109 female alpine skiers between 2004 and 2011. Subjects ranged between regional and national level of performance and were grouped according to their competition age groups (U12, 11 y; U14, 12–13 y; U16, 14–15 y; U18, 16–17 y; U21, 18–20 y) and performance level.

Results:

A progressive increase in anthropometric measures and improvements in tests results with increasing age were found. For all tests, male athletes had better results than female athletes. Minor differences were observed in anthropometric characteristics between 2004 and 2011 (mostly <5%), while results of physical and coordinative tests showed significant improvements (up to more than 50% enhancement) or stability over the years. Differences between higher- and lower-level athletes were more pronounced in tests for lower-limb strength and anaerobic capacity.

Conclusions:

The presented profile of young Swiss alpine skiers highlights the improvements in different physical aspects along the maturation process and chronologically over a period of 7 y. Furthermore, reference values are provided for comparisons with alpine skiers or athletes from other sports.

Open access

Yolanda Demetriou, Antje Hebestreit, Anne K. Reimers, Annegret Schlund, Claudia Niessner, Steffen Schmidt, Jonas David Finger, Michael Mutz, Klaus Völker, Lutz Vogt, Alexander Woll and Jens Bucksch