LONGITUDINAL FITNESS TESTING – SUPERVISION OF TRAINING IN YOUNG ALPINE SKI RACERS

Alpine ski racing demands a multitude of technical skills and excellent physical abilities. Longitudinal systematic fitness testing and supervision of training in young alpine ski racers is one key factor in the success of the Austrian ski teams. The established norm profiles for sport motor function and fitness tests in all age groups of ski racers can help in detecting fitness deficits early. Testing over the last 10 years has shown that Austrian young ski racers (e.g. boys) have an excellent conditioning level compared to other youth athletes from different sport disciplines. Testing of training efficiency demands that the coaches continually critique and revise their programs. Coordinated off/on snow courses and optimal intergroup communications under the supervision of the Austrian Ski Federation are important frameworks for a scientific based longitudinal training process

POWER TESTING IN ELITE SPORT AND PRACTICAL APPLICATIONS FOR TRAINING

The ability to produce force quickly is often a deciding factor in sport. Dynamic power assessment is related to complex aspects of muscle function as well as target performance in sports. In this sense, dynamic power testing includes multi-joint movements such as jumping under typical real life conditions. Testing of power is important, but understanding the results and ultimately using them to improve training is the goal of the testing process. The purpose of this paper is to describe a system of power testing and how the results are used in training

BIOMECHANIC ASPECTS OF SPORT SPECIFIC TESTING IN ELITE ALPINE SKI RACERS

The long record of consistent success in all age groups of Austrian alpine ski racers is due to an optimized training environment. One of many factors is physical preparation. The physical preparation program of the Austrian Ski Federation ski racers has for years included tests in which specially designed test devices and computer programs are utilized. The testing series for the Austrian ski team members include the following devices: Biodex balance and coordination tests, Isometric power tester (max. isometric strength tests of knee and hip extension), Back Check (max. isometric core strength tests). MLD (barbell squat jumps and counter movement jumps with varying loads), Kistler force plate (CMJ, special power jump tests & reactive strength). Contrex (concentric/eccentric maximal strength & strength endurance of the hip and knee extensors) & Ski start test (maximal force and impulse of right and left pole-pushes as well as the acceleration). The development of physical preparedness norms for ski racers at all age levels aids in performance prediction, but even of more consequence -assists in injury prevention. Necessary measures can then be undertaken to help the athlete make the gains needed

Effects of synchronous, auditory stimuli on running performance and heart rate

Research has demonstrated that the human being tends to couple body movements and external, acoustic stimuli (metronome or music). This effect is called auditory-motor synchronization. Motivational music possesses qualities which distract from feelings like fatigue and exertion. Combining these two effects may enhance the sports performance even more. Investigations showed that runners can increase their original cadence up to 2%. The purpose of this study was to examine the effects of accelerated, synchronized stimuli on the running performance. Therefore, 28 students (15 ♀, 13 ♂) of the Institute of Sports Science in Innsbruck were asked to do two cooper tests each. After run 1 (no auditory signal), the sample was divided into two groups. In run 2, which took place on a different day, one group listened to music while running; the other group was stimulated by the sound of a metronome. Distance (m) and average heartrate were measured. 75% of the athletes achieved a greater distance under the influence of an acoustic stimulus. In fact, the running distance changed significantly using an acoustic stimulus: +61 m (SD ± 100) or 2.1% (SD ± 3.6). In group 1 (music), the performance improved up to + 3.8% (SD ± 3.3). This difference was significant compared to group 2 (metronome). The average heart rate decreased by 1.5 beats (SD ± 5) from run 1 to run 2. Influenced by music, the average heart rate measured 179 beats (SD ± 8) in contrast to 182 beats (SD ± 10) in run 1 (no acoustic stimulus). If the tempo of the acoustic stimulus is adapted to the accelerated cadence of an athlete (maximum 2%), improved distances due to the synchronization effect can be achieved. In combination with the motivating qualities of music, improved effects in sport performances could be produced

MEASURING DEVICE FOR ON-LINE CALCULATING AND SCREENING OF KNEE JOINT FORCES

INTRODUCTION: For calculating knee joint forces quasi-static and dynamic 2D knee models have been developed (Moeinzadeh et al., 1983, Nisell, 1985, Yamaguchi/ Zajac, 1989). From the preventive point of view the on-line calculation and screening of knee joint forces could give us important simultaneous feedback on the loads on the different structures during training and performance exercises in several sports. Based on these considerations an existing 2D knee model should be adapted for on-line calculating and screening of knee joint forces. METHODS: The purpose is to determine the kinematics of the knee joint as function of the knee angle. Therefore data from Yamaguchi/Zajac (1989), Nisell (1985) and ourselves were combined to the 2D model called 'Plakmos'. All relevant parameters needed for determining the kinematics of the knee were calculated for knee angles between 0° and 96° in steps of 2°. In a further procedure these data were calculated as polynomial functions of the knee angle up to order 10 using non-linear regression technique. These functions in combination with the direction, the magnitude and the point of application of the ground reaction force (GRF) are sufficient to obtain the main compression, shear and tendon forces. A special measuring device consisting of a force platform (for determining the direction, magnitude and application point of the GRF) and two goniometers (to obtain the ankle and knee angles) yields the input data for calculating the knee joint forces. The data collection and the calculation procedure is carried out using the measuring software Dasylab. RESULTS: The kinematics of Plakmos coincides with the knee models reported very closely, so the validity of the model is given with sufficient accuracy to investigate at least relative comparisons in different situations. The utility and simplicity of the measuring device including Plakmos has been demonstrated in comparative studies of knee bending with and without additional weights and different knee bending techniques. REFERENCES: Moeinzadeh, M., Engin, A., Akkas, N. (1983). Two-Dimensional Dynamic Modeling of Human Knee Joint. J. Biomechanics 16, 253-264. Nisell, R. (1985). Mechanics of the Knee. A. Orth. Scand, Suppl. 216, 56, 4-42. Yamaguchi, G., Zajac, F. (1989). A Planar Model of the Knee Joint to Characterize the Knee Extensor Mechanism. J. Biomechanics 22, 1-10

EFFECTS OF AN 8-WEEK KNEE INJURY PREVENTION PROGRAM AND TECHNIQUE MODIFICATION TRAINING ON CHANGE-OF-DIRECTION PERFORMANCE

The purpose of this analysis was to determine whether an 8-week knee injury prevention program with an additional focus on change-of-direction (COD) technique training results in improved COD performance compared to a control training group with a focus on linear sprint training. Although both groups showed indicators for superior performance during a 135-degree COD, such as a more effective reorientation of the body, the COD technique modification component was ineffective in improving overall COD completion time or ground contact times. Follow-up analyses will show whether the COD group adopted a safer COD movement strategy following training, e.g. by reducing the knee valgus loading

Biological Maturity Status, Anthropometric Percentiles, and Core Flexion to Extension Strength Ratio as Possible Traumatic and Overuse Injury Risk Factors in Youth Alpine Ski Racers: A Four-Year Prospective Study

The aim of the present study was to investigate prospectively the role of biological maturity status, anthropometric percentiles, and core flexion to extension strength ratios in the context of traumatic and overuse injury risk identification in youth ski racing. In this study, 72 elite youth ski racers (45 males, 27 females) were prospectively observed from the age of 10 to 14 years. Anthropometric parameters, biological maturity status, and core flexion to extension strength ratios were assessed twice per year. Type and severity of traumatic and overuse injuries were prospectively recorded during the 4 years. Generalized estimating equations were used to model the binary outcome (0: no injury; 1: ≥1 injury). Factors tested on association with injury risk were sex, relative age quarter, age, maturity group, puberty status, core flexion to extension strength ratio, height percentile group, and weight percentile group. In total, 104 traumatic injuries and 39 overuse injuries were recorded. Age (odds ratio (OR) = 3.36) and weight percentile group (OR = 0.38) were significant risk factors for traumatic injuries (tendency: pubertal status). No significant risk factor for overuse injuries was identified (tendency: maturity group, puberty status, height percentile group). Future studies should focus on identifying risk factors for overuse injuries; growth rates might be of importance

Training Behaviors and Periodization Outline of Omnivorous, Vegetarian, and Vegan Recreational Runners (Part A)—Results from the NURMI Study (Step 2)

Runners train for long-distance competitions based on underlying motivations, which may be similar to individual dietary motivations (e.g., well-being and performance). Fundamental training differences may arise in recreational runners following different diet types (omnivore, vegetarian, vegan) considering possible motive variations. Following a cross-sectional design, distance runners completed a survey (online), including a thorough assessment of training behaviors with generic training details and periodization specifics in three phases: 1. an intermediary and rebound stage, 2. a main preparatory stage, and 3. a main event stage (tapering or interim event level/s). Kruskal–Wallis and chi-squared tests were used in the statistical analysis. A total of 245 fit recreational runners following omnivore (n = 109), vegetarian (n = 45), and vegan diets (n = 91) were included. Significant differences in the initial running motivation were found across dietary subgroups (p = 0.033) as well as for current motivations (p = 0.038), with vegetarians being the least health motivated (27% and 9%, respectively). No differences in each of the specific periods were found between diet types across the outline (p > 0.05). The present evidence shows that there is a lack of fundamental training differences based on recreational runners following different generic types of diets. The results of the present investigation may be especially relevant for future studies on safety, sustainability, and performance-enhancing dietary practices among athletes

Racing Experiences of Recreational Distance Runners following Omnivorous, Vegetarian, and Vegan Diets (Part B)-Results from the NURMI Study (Step 2)

The potential running or endurance performance difference based on following different general types of diets, such as omnivorous, vegetarian, or vegan, remains questionable. Several underlying modifiable factors of long-distance running performance, especially runner training behaviors and experience, diminish the clarity of results when analyzing dietary subgroups. Based on the cross-sectional design (survey), the NURMI Study Step 2 aimed to investigate a plethora of training behaviors among recreational long-distance running athletes and the relationship of general diet types with best time race performance. The statistical analysis was based on Chi-squared and Wilcoxon tests. The final sample (n = 245) included fit recreational long-distance runners following an omnivorous diet (n = 109), a vegetarian diet (n = 45), or a vegan diet (n = 91). Significant differences were found between the dietary subgroups in body mass index (p = 0.001), sex (p = 0.004), marital status (p = 0.029), and running-related motivations for well-being (p 0.05). Whether the vegan diet is associated with enhanced endurance performance remains unclear. Although, the present results are suggestive that 100% plant-based (vegan) nutrition is compatible with distance running performance at the least