Comparison of Physical Characteristics and Performance Among Elite Snowboarders

Abstract

Platzer, H-P, Raschner, C, Patterson, C, Lembert, S. Comparison of physical characteristics and performance among elite snowboarders. J Strength Cond Res 23(5): 1427-1432, 2009-There are little scientific data regarding snowboarding and the physiological demands on snowboarders. The aim of this study was to assemble and evaluate a battery of tests for the snowboard disciplines parallel, snowboard cross (SBX), big air, and half-pipe (HP). Thirty-seven competitive snowboarders participated in the study and completed a test battery that comprised tests for aerobic capacity, balance, jumping, isokinetic core power, isokinetic leg power, isometric bench press, isometric bench pull, and a snowboard start simulator. The results showed that the battery of tests explained between 61 and 98% of variance when predicting snowboard performance. The test battery predicts better for women than for men and better for SBX, HP, and overall World Cup ranking than for the other disciplines. The results indicate that starting speed, leg power, core power, and aerobic capacity are important in different snowboarding events.

Introduction

Snowboarding is a relatively new sport that is especially attractive for younger people. The International Olympic Committee recognized that trend over the last 2 decades and introduced snowboarding into Olympic competition in 1998. Snowboarding has become more and more popular but scientific data are scarce. There are only a few published articles regarding biomechanics in snowboarding (²⁰). Scientists have examined injuries in recreational snowboarding (^3,5,9,17), but studies with competitive athletes have been conducted (^18,19). To the authors' knowledge, there are no studies dealing with fitness testing or physiological profiling in snowboarding. To understand the physical demands of snowboarding, the different disciplines shall be briefly described.

In freestyle, there is a half-pipe (HP) event that has been Olympic since 1998 and a big air event. These events are artistic and the athletes perform spectacular tricks. Competitors should be courageous and fit because big air has the highest incidence of injuries (^18,19). The skateboard cult in the 80s formed the snowboard movement, which led to the first self-made HPs.

The parallel discipline comprised 2 different events: giant slalom, which has been Olympic since 2002, and the slalom. Here, 2 contestants race against head to head. A run lasts approximately 30 seconds, and 10 races must be won to win a competition.

The first snowboard cross (SBX) Olympic competitions were in Turin (2006). Here, 4 competitors start together and race on the same course. There are several obstacles such as kickers, gates, steep turns, and bumpers, so crashes are frequent in this event. From qualifying to final, there is a maximum of 8 runs.

The physiological requirements in snowboarding are diverse. Athletes need strength, aerobic fitness, coordination, and more to prevail in a contest and over an entire season. Other factors such as technique, equipment, or psychology are important as well, but this study analyzed only the physiological variables.

To evaluate physiological factors, fitness testing in sports is absolutely necessary. Laboratory tests are a useful tool to assess the athlete's general fitness (^11,16). These data are used to monitor training and for training prescription. Tests should have a relevance to the specific sport and be able to predict performance (^1,2,4,8,10). These approaches were the basis for the aims of the study, which were to compile a test battery and to evaluate this test battery for each discipline.

Methods

Experimental Approach to the Problem

This study used a battery of tests to compare physical fitness with snowboard performance. Tests for aerobic fitness, balance, jumping, core and leg power, upper-body strength, and a snowboard start simulator were conducted. Each participant completed at least 3 trials for each test. Test results were correlated to FIS (Fédération Internationale de Ski) points in the different disciplines and overall World Cup (WC) points.

Subjects

Thirty-seven athletes (21 men and 16 women) from the Austrian national snowboard team served as participants. The athletes were members of junior (n = 4), European Cup (EC) (n = 9), and WC (n = 24) teams. This group includes world champions and overall WC winners. Over a year, they spend up to 115 training days on snow, depending on how many disciplines they compete in. General physical preparation takes place from May to the end of July and consists mainly of strength and endurance training. Snowboarding is a relatively new sport, so the specific physical preparation is still evolving. Each athlete is obligated by the Austrian Ski Federation to participate in medical screening and physical fitness tests annually. These tests should reveal individual strengths and weaknesses in the fitness profile. Junior athletes were included because of their several years' experience in FIS races and their regular participation in EC races. The subjects' anthropometric and age data are shown in Table 1. The athlete's spans for all variables are presented in Table 2. All disciplines were represented with the exception that there were no female freestylers. All participants were free from injuries and were informed of any risks associated with participation in the tests. The athletes or their parents (if the snowboarders were minors) signed a written informed consent form, and the athletes participated in the study on a voluntary basis. This study was approved by our University Committee on Human Research, and testing was carried out according to the Declaration of Helsinki.

Table 1: Mean ± SD for body height, body mass, and age.

Table 2: Spans for all variables in both groups.*

Procedures

All tests were performed in May, 1 month after the end of the 2006/2007 season, at the beginning of the general physical preparation period. The bicycle ergometry test (GE Medical Systems; General Electrics Company, Fairfield, CT) was administered on a separate day at the Institut für Sport- und Kreislaufmedizin of the Innsbruck University Hospital. Relative power (watts per kilogram) from the last stage of a continuous incremental test (start at 50 W for women, 100 W for men, and 50-W increments every 3 minutes) was analyzed. All other tests were administered in 1 session on another day. For the strength and stability tests, all participants warmed up on a cycle ergometer, at 100 W for 10 minutes. Each test then included warm-up trials on the testing device before the actual test was administered. For all strength tests, 3 maximal contractions were conducted and the greatest value was recorded. All participants performed the tests in the same order, with at least 5 minutes between each test. The test battery consisted of the following tests:

A countermovement jump with hands on hips on a Kistler platform (Kistler Instrumente AG, Winterthur, Switzerland) was carried out to measure jump height (centimeters).

The isokinetic leg power test was performed on a Con-Trex leg press (CMV AG, Zürich, Switzerland). Measurements are made unilaterally with the right and left legs. The range of motion was set between knee angles of 85 and 120°. The testing speed was set at 0.2 m·s⁻¹ for concentric extension and flexion contractions. Relative concentric power values (watts per kilogram) for left and right legs in flexion and extension were summed together.

The isokinetic core test was carried out with the Con-Trex TP-1000 trunk module (CMV AG). For the isokinetic core test, the range of motion is set between hip angles of 0 and 60° (standing upright is 0°). The testing speed was set at 150 degrees per second for concentric extension and flexion contractions. Relative concentric power values (watts per kilogram) for hip flexion and extension were summed together.

The hardware (MLD-Station Evo2) and software (MLD 2.0; Muskel-Leistungs-Diagnose 2.0) from SPSport (SP Sportdiagnosegeräte GmbH, Trins, Austria) were used to collect data from bench press and pull. The software version MLD 2.0 measures the ground reaction force obtained from the force platforms. The hardware and software have been described in a previous study (¹²). Isometric bench press and bench pull were performed on a bench bolted to the force platform inside of a power rack. Bench press elbow angle was measured as the subject lay prone face up on the bench and pressed an Olympic bar against the safety pins of the power rack. The landmarks of acromioclavicular joint, lateral epicondyle of the humerus, and the styloid process of the ulna were used to determine elbow angle. The safety pins of the power rack were adjusted so that elbow angle was 90°. The grip width (between index fingers) for men was 61.5 cm and for women was 53.5 cm. Knees were raised so that the thighs were perpendicular to the floor, with a knee angle of approximately 90°. Before the measurement, the athlete raised the bar up to the pins. The subject then pressed maximally for approximately 4 to 5 seconds. The peak maximal force exerted on the force platform was recorded.

Bench pull elbow angle was measured as the subject lay face down on the bench and pulled the bar up against the pins. Elbow angle and grip width were as in bench press. Before the measurement, the athlete raised the bar up to the pins and then pulled maximally for approximately 4 to 5 seconds. Here, relative strength of bench press and pull (newtons per kilogram) was summed together. This test was not conducted in the freestyle group.

A one-legged static balance test on the Biodex Balance System (Biodex, Inc., Shirley, NY) was used to measure stability. Test duration was 30 seconds at a spring resistance level of 2. Two test trials were given and the best value was analyzed. Measured variable for the static balance test was a mean of the stability indices of the left and right legs.

An indoor start simulator (Figure 1) was used to measure maximum push off speed (meters per second). A motion transducer (EMIX 3; Regatronic, Austria) on the sled and a magnetic band (MB20.20; Regatronic, Gramastetten, Austria) on the rail are used to measure displacement, enabling speed, and acceleration analysis. Additionally, 2 U2B force transducers (HBM GmbH, Darmstadt, Germany) are connected to the start handles to allow force measurements on the right and the left start handles. All measured data were analyzed and displayed by a LabView program (National Instruments, Corp., Austin, TX). This test was not administered for the freestyle group.

Figure 1: Test on the indoor start simulator.

Test-retest reliability is rarely evaluated with athletes tested in this laboratory. We conducted an internal study to investigate the intraclass correlation (ICC) for the test variables used here. The indoor start simulator has been described and evaluated by Raschner et al. (¹³), with ICCs between 0.80 and 0.98. Intraclass correlations for the tests were as follows: one-legged static balance test (left and right legs) was 0.87 to 0.91, the isokinetic leg power test was (left and right legs) between 0.94 and 0.97, isokinetic core test (flexion and extension) was 0.77 to 0.90, countermovement jump was 0.91, and bench pull and bench press test was between 0.93 and 0.98.

FIS points were taken from the sixth FIS Snowboard Point List 2006/2007 (⁶) and overall WC points at the end of the season 2006/2007 (⁷) from the snowboard database on the FIS Web site. FIS points were only analyzed for the athlete's main events. Therefore, 12 men and 13 women had results in parallel events, 10 men and 12 women in SBX events, and 9 men in freestyle events (9 big air, 6 HP). No female freestylers were tested. For overall WC, the results of 13 men and 10 women were analyzed. One WC athlete was injured, so had no overall WC ranking.

Statistical Analyses

For statistical analysis, a Kolmogorov-Smirnov test to check for normal distribution and a Pearson correlation coefficient to correlate the variables with FIS and WC points were used. To identify variables important in predicting snowboarding performance, a multiple regression analysis (including tests for collinearity and a check for normally distributed residuals) was carried out. Statistical power was calculated with a G*power analysis. Independent t-tests were carried out to describe differences between EC and WC snowboarders and to compare men and women. Statistical significance was set at p ≤ 0.05.

Results

The women in this study had higher mean overall WC points than the men (p < 0.05). Mean FIS points in parallel and SBX events did not differ between men and women (p > 0.05). The men displayed higher means for all tests than the women (p < 0.05).

Table 3 shows results for the correlation analysis for women. In men, the only significant correlation was found between countermovement jump and HP FIS points (r = 0.88, p < 0.05), so results for men were not included in Table 3. Bicycle ergometry and leg power were the only tests for women that correlated with FIS points in parallel events. FIS points for SBX in women showed significant correlations to all tests but countermovement jump. Overall WC points in women correlated with bicycle ergometry and leg power. In HP, the only significant correlation with FIS points was countermovement jump. The results for the regression analysis are presented in Table 4. Men's big air, parallel, and SBX were excluded because no significant regression was found for these events. The test battery explained 61% of the variance of FIS points in women's parallel events and 78% of variance of FIS points in men's HP. The tests explained 98% of variance in women's FIS points for SBX and 61 and 73% of variance in overall WC points in men and women, respectively. In women, WC racers showed significantly better results in countermovement jump and core power (p < 0.05) than EC racers. In men, no significant difference could be observed between EC and WC athletes in any of the fitness variables. All regression models revealed 1 model that included only 1 independent variable. All other variables were excluded in the models. The inclusion of additional variables did not lead to a better explanation in variance of FIS and WC points.

Table 3: Correlation coefficients between fitness variables and FIS/WC points in women.†

Table 4: Regression coefficients for outcome variables with strongest predictors.†

Discussion

The complete test battery is a good predictor for snowboard performance in women but not for men. The regression analyses did not produce any result for big air, parallel, and SBX events in men. Other performance-determining factors such as psychology, equipment, and coordination might have as much or more influence on performance as the physical fitness parameters measured.

The test battery is a strong predictor of SBX FIS points in women with maximum push off speed as the best prognostic variable, which is also evidence for the importance of the start. Maximum push off speed explains most of the SBX variance, supporting the opinions of coaches and racers that the start in SBX is crucial for finishing position. Core power and bench press/pull strength are correlated to SBX performance in women because upper-body and posterior chain strength are critical at the start. Core power and stability are crucial when negotiating obstacles or colliding with other contestants. The correlation between SBX/parallel performance in women and bicycle ergometry demonstrates the necessity of aerobic fitness in these events. There are a high number of races per day (up to 10 races) with little regeneration time between runs. Often an athlete will be driven by snowmobile up to the start immediately after a run if he or she has qualified for the next round (Felix Stadler, snowboard coach, WC Group, oral communication, May 2007). This can trigger psychosocial and physiological stress that could be positively influenced by greater aerobic fitness (^14,15).

The explanation of variance in overall WC points in women (73%) is good, but the SEE indicates that the accuracy of this prediction is limited. Aerobic fitness is the best predictor for overall WC points. This supports the conviction of many sport scientists and coaches that a good aerobic base is fundamental to performance success. The combination of a long season (October to March), much travel, numerous training camps, and a high number of competitions (especially for athletes competing for the overall WC) is very taxing for an athlete. Next to aerobic fitness, leg power seems to be important for overall WC, parallel, and SBX performance in women.

Men's HP results are related to jump height in the countermovement jump. The freestyle group consisted only of 9 men, so this correlation should be interpreted carefully. Half-pipe coaches maintain that an athlete should not jump at take off but agree that explosive leg strength is an advantage. An athlete with more hang time (time spent in the air) can perform more sophisticated tricks, which results in better judge's scores.

The predictive value of this test battery on snowboard performance seems to be higher than test batteries for hockey players (⁴) or cyclists (¹⁰) and similar to test batteries for basketball players (⁸).

Physical fitness is a performance-determining factor in snowboarding, but women's performance levels were reflected more in the test results than those of the men. Few EC racers were tested, so the comparison between WC and EC shows a tendency but should be interpreted with care. The inability of the test battery to differentiate between EC and WC men indicates a more homogenous general fitness level in men than in women. Perhaps, in international snowboarding, men are more homogenous in general fitness than the women, so fitness plays a greater role in women's events.

Even if physical fitness is not statistically a limiting factor in men, one cannot afford to be unfit. An adequate fitness level must be reached, and this battery of tests can be used as a monitoring instrument. For female snowboarders, improving strength and power abilities could lead to better performances on the snow.

The various disciplines have different requirements and test batteries should reflect this. The test battery used here should be altered for parallel and especially for freestyle. Altering does not mean dropping tests, which show no or limited sport specificity, because they might be important for rehabilitation or general fitness training prescription. It should be possible to compile a test battery for freestyle with higher predictive properties by replacing some strength tests with coordination tests.

Practical Applications

When training elite athletes, testing is imperative and the testing battery should correlate to performance. The athletes need to see the relevance and usefulness of the tests so that an “all-out” effort is given. The battery should also aid scientists and coaches in prescribing training, assessing general fitness in healthy athletes, and assessing training readiness in injured athletes' rehabilitation. The chosen tests are practical for athletes who compete in SBX or have ambitions in the overall WC. Snowboarding has evolved from a “rebel” or “minority” sport to an established Olympic sport, and training programs should reflect this. This study should give coaches an insight into important exercises for training and testing snowboard athletes.

Acknowledgments

The authors would like to acknowledge the scientific board of the Austrian Ski Federation for its financial support; Mag. Esmeralda Mildner for her help during testing the athletes; the Institut für Sport- und Kreislaufmedizin of the Innsbruck University Hospital, especially, Dr. Barbara Semenitz for administering the bicycle ergometry; and the snowboard coaches (Felix Stadler, Thomas Greil, Johannes Bronnenmayer, Thomas Weninger, and Stefan Hanser) for recruiting the athletes.