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Tang W, Suo X, Wang X, Shan B, Li L, Liu Y. SnowMotion: A Wearable Sensor-Based Mobile Platform for Alpine Skiing Technique Assistance. SENSORS (BASEL, SWITZERLAND) 2024; 24:3975. [PMID: 38931758 PMCID: PMC11207317 DOI: 10.3390/s24123975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 06/17/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024]
Abstract
Skiing technique and performance improvements are crucial for athletes and enthusiasts alike. This study presents SnowMotion, a digital human motion training assistance platform that addresses the key challenges of reliability, real-time analysis, usability, and cost in current motion monitoring techniques for skiing. SnowMotion utilizes wearable sensors fixed at five key positions on the skier's body to achieve high-precision kinematic data monitoring. The monitored data are processed and analyzed in real time through the SnowMotion app, generating a panoramic digital human image and reproducing the skiing motion. Validation tests demonstrated high motion capture accuracy (cc > 0.95) and reliability compared to the Vicon system, with a mean error of 5.033 and a root-mean-square error of less than 12.50 for typical skiing movements. SnowMotion provides new ideas for technical advancement and training innovation in alpine skiing, enabling coaches and athletes to analyze movement details, identify deficiencies, and develop targeted training plans. The system is expected to contribute to popularization, training, and competition in alpine skiing, injecting new vitality into this challenging sport.
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Affiliation(s)
- Weidi Tang
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China; (W.T.); (X.W.); (B.S.); (L.L.)
| | - Xiang Suo
- School of Athletic Performance, Shanghai University of Sport, Shanghai 200438, China;
| | - Xi Wang
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China; (W.T.); (X.W.); (B.S.); (L.L.)
| | - Bo Shan
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China; (W.T.); (X.W.); (B.S.); (L.L.)
| | - Lu Li
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China; (W.T.); (X.W.); (B.S.); (L.L.)
| | - Yu Liu
- Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China; (W.T.); (X.W.); (B.S.); (L.L.)
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Sauvé B, Haugan M, Paulsen G. Physical and Physiological Characteristics of Elite CrossFit Athletes. Sports (Basel) 2024; 12:162. [PMID: 38921856 PMCID: PMC11209587 DOI: 10.3390/sports12060162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/22/2024] [Accepted: 06/07/2024] [Indexed: 06/27/2024] Open
Abstract
Due to little available research on elite CrossFit athletes, the present investigation was undertaken to provide knowledge about their physical and physiological characteristics. Nineteen international level CrossFit athletes (8 men; 11 women) were tested for maximum oxygen consumption (V˙O2max), Wingate, squat 1 repetition maximum (1RM), countermovement jump (CMJ), lower body force-velocity, and body composition (DXA). To provide perspective, the results were compared to sixteen elite-level Alpinists (8 men; 8 women). There was no significant difference in absolute nor relative V˙O2max between the CrossFit and Alpinist men (p = 0.335 and p = 0.279, respectively). The CrossFit women showed similar absolute but higher relative V˙O2max than the Alpinist women (p = 0.055 and p = 0.005, respectively). Mean anaerobic power was higher in both CrossFit men and women (p = 0.021 and p = 0.008, respectively). There were no significant differences in squat 1RM and CMJ for both men and women (p > 0.05). Both CrossFit men and women showed lesser lower body force production (p = 0.043 and p = 0.034, respectively) but higher power (p = 0.009 and p = 0.003, respectively). The CrossFit men and women had a lower fat mass (p = 0.018 and p = 0.002, respectively) and fat percentage (p = 0.027 and p < 0.001, respectively). These observations show that elite CrossFit athletes possess physical and physiological characteristics comparable to world-class Alpinists.
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Affiliation(s)
- Bram Sauvé
- Department of Physical Performance, Norwegian School of Sport Sciences, Sognsveien 220, 0863 Oslo, Norway; (M.H.); (G.P.)
| | - Magnus Haugan
- Department of Physical Performance, Norwegian School of Sport Sciences, Sognsveien 220, 0863 Oslo, Norway; (M.H.); (G.P.)
| | - Gøran Paulsen
- Department of Physical Performance, Norwegian School of Sport Sciences, Sognsveien 220, 0863 Oslo, Norway; (M.H.); (G.P.)
- Norwegian Olympic Federation, Sognsveien 228, 0863 Oslo, Norway
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Yao Y, Niu X. Physical fitness characteristics of elite freestyle skiing aerials athletes. PLoS One 2024; 19:e0304912. [PMID: 38843216 PMCID: PMC11156283 DOI: 10.1371/journal.pone.0304912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/20/2024] [Indexed: 06/09/2024] Open
Abstract
OBJECTIVE To analyze the physical fitness characteristics of elite freestyle skiing aerials athletes, thereby enhancing the understanding of exercise physiologists, sports scientists, and coaches regarding the demands in this discipline. METHODS After health screenings, 29 athletes from the Chinese National Freestyle Skiing Aerials Team were divided into elite and general groups, including males and females. Physical fitness indexes were determined through literature reviews, expert interviews, and the Delphi method, followed by physical fitness tests assessing body morphology, physiological function, and physical quality. Data normality was verified using the Shapiro-Wilk test. Differences between the two groups were then evaluated using independent sample t-tests or Mann-Whitney U tests, after which effect sizes were calculated to assess the magnitude of the differences. RESULTS Significant body morphology differences were noted between elite and general groups in fat-free body weight, leg, and waist circumferences (P < 0.05). Male athletes in the elite group exhibited a significantly lower percentage of body fat (P < 0.05), whereas the reduction in body fat percentage among female elite athletes was not statistically significant. In terms of physiological function assessment, elite athletes demonstrated superior performance in both maximum anaerobic capacity and relative maximum anaerobic capacity compared to their counterparts in the general group (P < 0.05). Notably, the difference in maximum anaerobic capacity was highly significant among male athletes (P < 0.01), and the relative maximum anaerobic capacity among female athletes was also markedly significant (P < 0.01). Regarding physical quality indexes, elite athletes outperformed those in the general group in all aspects except for the quick v-up and 12-minute run tests (P < 0.05 or P<0.01). CONCLUSION Elite athletes exhibit superior physical fitness characteristics compared to general athletes, attributable to differences in age, years of training, and their participation in ongoing specialized physical training within structured, cyclical programs. Specifically, elite athletes demonstrated higher fat-free body weight, larger waist and leg circumferences in terms of body morphology. Particularly, male athletes showed a trend towards lower body fat percentage. Physiologically, they exhibited stronger anaerobic metabolism capabilities. In terms of physical quality, elite athletes displayed superior limb strength, lower limb explosive power, and specialized core strength, along with better speed, agility, and overall coordination.
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Affiliation(s)
- Youwei Yao
- School of Sports Training, Shenyang Sport University, Shenyang, China
| | - Xuesong Niu
- School of Social Sports, Shenyang Sport University, Shenyang, China
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Bertozzi F, Tenderini D, Camuncoli F, Simoni G, Galli M, Tarabini M. Bioimpedance Vector Analysis-Derived Body Composition Influences Strength and Power in Alpine Skiers. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2024:1-7. [PMID: 38319327 DOI: 10.1080/02701367.2023.2298464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 12/19/2023] [Indexed: 02/07/2024]
Abstract
Purpose: Alpine ski racing is a complex sport where no single factor can exclusively account for performance. We assessed body composition, using bioelectrical impedance vector analysis (BIVA), and our purpose was to study its influence on the strength and power profile of young alpine skiers. Methods: Anthropometric measurements and advanced BIVA parameters were recorded on eighteen alpine ski racers (6 females/12 males; 17.0 ± 1.3 years; 172.2 ± 9.3 cm; 68.5 ± 9.8 kg). Dynamic force and power were assessed using countermovement jumps (CMJ), while maximal isometric strength was evaluated for hip flexion-extension and abduction-adduction movements. Stepwise regression models examined the relationship between BIVA-derived parameters and strength/power variables. Results: Body cellular mass (BCM) positively related to jump height (p = .021, R2 = 74%), jump momentum (p < .001, R2 = 89%), reactive strength index modified (p = .026, R2 = 75%) and peak concentric power (p < .001, R2 = 82%), while intracellular water (ICW) related to peak eccentric (p < .001, R2 = 76%) and concentric force (p < .001, R2 = 77%) as well as to concentric rate of force development together with the phase angle (PhA) (p = .008, R2 = 79% and R2 = 0.015). Regarding isometric assessment, ICW was a significant predictor for all four movement directions, and PhA contributed to hip adduction strength. Conclusions: Body composition, particularly BCM and ICW, significantly predict force- and power-related factors in young alpine skiers.
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Bjerke Ø, Lorås H, Pedersen AV. Constituent Year Effects and Performance in Alpine Skiing Junior World Championships. Sports (Basel) 2023; 11:155. [PMID: 37624135 PMCID: PMC10457790 DOI: 10.3390/sports11080155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/08/2023] [Accepted: 08/14/2023] [Indexed: 08/26/2023] Open
Abstract
This study examines constituent year effect (CYE) and race performance among junior alpine skiers in the World Championships. In various junior age cohorts competing together, variation in skiing performance can be expected not only due to practice load and experience but also due to inter-individual differences in physical and psychological maturation. Within a one-year cohort, this effect has been referred to as the birth month effect or the relative age effect (RAE). In cohorts with multiple age bands, the effect is termed the constituent year effect (CYE). The CYE works in principle as the RAE but can function as a magnifying lens of the development within a larger multi-year cohort. The results of the current study indicate that CYEs are present among junior alpine skier performance in the junior World Championships. The magnitude of the constituent year effect is greater in speed events (i.e., downhill and super-G) than in technical events (i.e., slalom and giant slalom), and greater among male skiers compared to female skiers. The findings are discussed in relation to previous research on relative age effects more generally and within the sport context specifically.
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Affiliation(s)
- Øyvind Bjerke
- Department of Teacher Education, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Håvard Lorås
- Department of Teacher Education, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Arve Vorland Pedersen
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, 7030 Trondheim, Norway
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Gasser B, Frey WO, Valdivieso P, Scherr J, Spörri J, Flück M. Association of Gene Variants with Seasonal Variation in Muscle Strength and Aerobic Capacity in Elite Skiers. Genes (Basel) 2023; 14:1165. [PMID: 37372345 DOI: 10.3390/genes14061165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
Background: The training of elite skiers follows a systematic seasonal periodization with a preparation period, when anaerobic muscle strength, aerobic capacity, and cardio-metabolic recovery are specifically conditioned to provide extra capacity for developing ski-specific physical fitness in the subsequent competition period. We hypothesized that periodization-induced alterations in muscle and metabolic performance demonstrate important variability, which in part is explained by gene-associated factors in association with sex and age. Methods: A total of 34 elite skiers (20.4 ± 3.1 years, 19 women, 15 men) underwent exhaustive cardiopulmonary exercise and isokinetic strength testing before and after the preparation and subsequent competition periods of the World Cup skiing seasons 2015-2018. Biometric data were recorded, and frequent polymorphisms in five fitness genes, ACE-I/D (rs1799752), TNC (rs2104772), ACTN3 (rs1815739), and PTK2 (rs7460, rs7843014), were determined with specific PCR reactions on collected DNA. Relative percentage changes of cardio-pulmonary and skeletal muscle metabolism and performance over the two seasonal periods were calculated for 160 data points and subjected to analysis of variance (ANOVA) to identify hypothesized and novel associations between performance alterations and the five respective genotypes and determine the influence of age × sex. A threshold of 0.1 for the effect size (h2) was deemed appropriate to identify relevant associations and motivate a post hoc test to localize effects. Results: The preparation and competition periods produced antidromic functional changes, the extent of which varied with increasing importance for anaerobic strength, aerobic performance, cardio-metabolic efficiency, and cardio-metabolic/muscle recovery. Only peak RER (-14%), but not anaerobic strength and peak aerobic performance, and parameters characterizing cardio-metabolic efficiency, differed between the first and last studied skiing seasons because improvements over the preparation period were mostly lost over the competition period. A number of functional parameters demonstrated associations of variability in periodic changes with a given genotype, and this was considerably influenced by athlete "age", but not "sex". This concerned age-dependent associations between periodic changes in muscle-related parameters, such as anaerobic strength for low and high angular velocities of extension and flexion and blood lactate concentration, with rs1799752 and rs2104772, whose gene products relate to sarcopenia. By contrast, the variance in period-dependent changes in body mass and peak VO2 with rs1799752 and rs2104772, respectively, was independent of age. Likely, the variance in periodic changes in the reliance of aerobic performance on lactate, oxygen uptake, and heart rate was associated with rs1815739 independent of age. These associations manifested at the post hoc level in genotype-associated differences in critical performance parameters. ACTN3 T-allele carriers demonstrated, compared to non-carriers, largely different periodic changes in the muscle-associated parameters of aerobic metabolism during exhaustive exercise, including blood lactate and respiration exchange ratio. The homozygous T-allele carriers of rs2104772 demonstrated the largest changes in extension strength at low angular velocity during the preparation period. Conclusions: Physiological characteristics of performance in skiing athletes undergo training period-dependent seasonal alterations the extent of which is largest for muscle metabolism-related parameters. Genotype associations for the variability in changes of aerobic metabolism-associated power output during exhaustive exercise and anaerobic peak power over the preparation and competition period motivate personalized training regimes. This may help to predict and maximize the benefit of physical conditioning of elite skiers based on chronological characteristics and the polymorphisms of the ACTN3, ACE, and TNC genes investigated here.
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Affiliation(s)
- Benedikt Gasser
- Department of Sport, Physical Activity and Health, University of Basel, 4052 Basel, Switzerland
| | | | - Paola Valdivieso
- Laboratory for Muscle Plasticity, Balgrist Campus, University of Zurich, 8008 Zurich, Switzerland
| | - Johannes Scherr
- University Centre for Prevention and Sports Medicine, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, 8008 Zurich, Switzerland
| | - Jörg Spörri
- University Centre for Prevention and Sports Medicine, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, 8008 Zurich, Switzerland
- Sports Medical Research Group, Department of Orthopaedics, Balgrist University Hospital, University of Zurich, 8008 Zurich, Switzerland
| | - Martin Flück
- Department of Sport, Physical Activity and Health, University of Basel, 4052 Basel, Switzerland
- Laboratory for Muscle Plasticity, Balgrist Campus, University of Zurich, 8008 Zurich, Switzerland
- Department of Medicine, University of Fribourg, 1700 Fribourg, Switzerland
- Swiss Federal Institute of Sport-BASPO, 2532 Magglingen, Switzerland
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Penitente G, Young HA, Sands WA, McNeal JR. A Classification of Fitness Components in Elite Alpine Skiers: A Cluster Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:ijerph20105841. [PMID: 37239567 DOI: 10.3390/ijerph20105841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/16/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023]
Abstract
The current study is an exploratory, secondary data analysis of a selection of physiological and biomechanical fitness components used to assess elite alpine skiers. The present study will provide new knowledge that can be used to aid training prescription and talent identification. A hierarchical cluster analysis was used to identify groups of variables that are crucial for elite alpine skiers and differences based on sex and competition level. The key findings of the study are the patterns that emerged in the generated dendrograms. Physiological and biomechanical fitness components are differentiated in the dendrograms of male and female world-cup-level alpine skiers, but not in non-world-cup athletes. Components related to the aerobic and anaerobic capacity tightly cluster in male athletes at world cup and non-world-cup level, and female world cup athletes. Lower body explosive force production appears to be more critical in male world cup athletes than female world cup athletes. More research is needed into the importance of isometric strength in the lower body. Future research should use larger sample sizes and consider other alpine ski demographics.
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Affiliation(s)
- Gabriella Penitente
- Academy of Sport and Physical Activity, Sheffield Hallam University, Sheffield S10 2BP, UK
| | - Hayden A Young
- Academy of Sport and Physical Activity, Sheffield Hallam University, Sheffield S10 2BP, UK
| | | | - Jeni R McNeal
- Department of Physical Education, Health and Recreation, Eastern Washington University, Cheney, WA 99004-2431, USA
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Moving Down the Slope: from Scaffolding to Autonomous Mastery. HUMAN ARENAS 2023. [DOI: 10.1007/s42087-022-00324-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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De Larochelambert Q, Barlier K, Hamri I, Difernand A, Sedeaud A, Toussaint JF, Antero J, Louis PY, Coulmy N. Potential estimation model in French alpine skiing - Individual evolution curve and progression typology. Front Physiol 2023; 13:1082072. [PMID: 36685191 PMCID: PMC9849383 DOI: 10.3389/fphys.2022.1082072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 12/07/2022] [Indexed: 01/07/2023] Open
Abstract
Estimating the potential of alpine skiers is an unresolved question, especially because of the complexity of sports performance. We developed a potential estimation model based solely on the evolution of performance as a function of age. A bayesian mixed model allowed to estimate the potential curve and the age at peak performance for the population (24.81 ± 0.2) and for each individual as the uncertainty around this curve. With Gaussian mixtures, we identified among all the estimates four types of curves, clustered according to the performance level and the progression per age. Relying on the uncertainty calculated on the progression curve the model created also allow to estimate a score and an uncertainty associated with each cluster for all individuals. The results allows to: i) describe and explain the relationship between age and performance in alpine skiing from a species point of view (at 0.87%) and ii) to provide to sport staffs the estimation of the potential of each individual and her/his typology of progression to better detect sports potential. The entire methodology is based on age and performance data, but the progression identified may depend on parameters specific to alpine skiing.
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Affiliation(s)
- Quentin De Larochelambert
- Institut de Mathématiques de Bourgogne, UMR 5584 CNRS, Université Bourgogne Franche-Comté, Dijon, France,Institut de Recherche bioMédicale et d’Epidémiologie du Sport, EA7329, INSEP, Université de Paris, Paris, France,Scientific Department, French Ski Federation, Annecy, France,*Correspondence: Quentin De Larochelambert,
| | - Kilian Barlier
- Institut de Recherche bioMédicale et d’Epidémiologie du Sport, EA7329, INSEP, Université de Paris, Paris, France
| | - Imad Hamri
- Institut de Recherche bioMédicale et d’Epidémiologie du Sport, EA7329, INSEP, Université de Paris, Paris, France
| | - Audrey Difernand
- Institut de Recherche bioMédicale et d’Epidémiologie du Sport, EA7329, INSEP, Université de Paris, Paris, France
| | - Adrien Sedeaud
- Institut de Recherche bioMédicale et d’Epidémiologie du Sport, EA7329, INSEP, Université de Paris, Paris, France
| | - Jean François Toussaint
- Institut de Recherche bioMédicale et d’Epidémiologie du Sport, EA7329, INSEP, Université de Paris, Paris, France,Centre d’Investigation en Médecine du Sport, Hôtel-Dieu, Assistance Publique, Hópitaux de Paris, Paris, France
| | - Juliana Antero
- Institut de Recherche bioMédicale et d’Epidémiologie du Sport, EA7329, INSEP, Université de Paris, Paris, France
| | - Pierre-Yves Louis
- Institut de Mathématiques de Bourgogne, UMR 5584 CNRS, Université Bourgogne Franche-Comté, Dijon, France,Institut Agro Dijon, PAM UMR 02.102, Université Bourgogne Franche-Comté, Dijon, France
| | - Nicolas Coulmy
- Scientific Department, French Ski Federation, Annecy, France
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Magelssen C, Haugen P, Reid R, Gilgien M. Is there a contextual interference effect for sub-elite alpine ski racers learning complex skills? Front Bioeng Biotechnol 2022; 10:966041. [PMID: 36185422 PMCID: PMC9521505 DOI: 10.3389/fbioe.2022.966041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Scientific understanding of the contextual interference effect stems mainly from studies on unskilled participants learning artificial laboratory tasks. Although one goal of such studies is to extrapolate the findings to include real-world learning situations such as sports, this generalization is not straightforward. This study tested the contextual interference effect with 66 sub-elite, competitive alpine ski racers who learned a new movement pattern−the pumping technique to increase velocity in slalom−by practicing this skill in three different slalom courses over a 3-day training period. The interleaved group practiced all three courses each day in a semi-random order. In contrast, the blocked group practiced only one course each day, which was randomized and counterbalanced across the participants in this group. A retention test was delivered 72 h after the last practice day. In contrast to our hypothesis, the interleaved group did not display significantly better retention than the blocked group. The interleaved group’s performance was also not significantly attenuated during skill learning compared to the blocked group. Our results underscore the importance of conducting motor learning experiments in natural environments to understand the conditions that facilitate learning beyond the laboratory environment.
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Affiliation(s)
- Christian Magelssen
- Institute for Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
- *Correspondence: Christian Magelssen,
| | - Per Haugen
- Institute for Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | | | - Matthias Gilgien
- Institute for Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
- The Norwegian Ski Federation, Oslo, Norway
- Center of Alpine Sports Biomechanics, Engadin Health and Innovation Foundation, Samedan, Switzerland
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Alhammoud M, Girard O, Hansen C, Racinais S, Meyer F, Hautier CA, Morel B. Repeated practice runs during on-snow training do not generate any measurable neuromuscular alterations in elite alpine skiers. Front Sports Act Living 2022; 4:829195. [PMID: 35966108 PMCID: PMC9372580 DOI: 10.3389/fspor.2022.829195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 06/28/2022] [Indexed: 11/26/2022] Open
Abstract
Background Alpine skiers typically train using repeated practice runs requiring high bursts of muscle activity but there is little field-based evidence characterizing neuromuscular function across successive runs. Purpose To examine the impact of repeated ski runs on electromyographic activity (EMG) of the knee extensors and flexors in elite alpine skiers. Methods Nineteen national team alpine skiers were tested during regular ski training [Slalom (SL), Giant Slalom (GS), Super Giant Slalom and Downhill (Speed)] for a total of 39 training sessions. The surface EMG of the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), biceps femoris (BF) and semimembranosus/semitendinosus (SMST) muscles was continuously recorded along with right knee and hip angles. The EMG root mean square signal was normalized to a maximal voluntary contraction (%MVC). The first and fourth runs of the training session were compared. Results There was no meaningful main effect of run on EMG relative activation time or mean power frequency beyond the skier's intrinsic variability. However, EMG activity of the vastii increased from the first to the fourth run in SL [VM, ~+3%MVC for IL and outside leg (OL), p = 0.035)], speed (VL, IL:+6%/OL:+11%, p = 0.015), and GS (VM, IL:0/OL:+7%, p < 0.001); the later with an interaction with leg (p < 0.001) due to a localized increase on the OL. The run time and turn time did not change from the first to the fourth run. There were no meaningful changes in angular velocities, amplitude of movement, or maximal and minimal angles. Conclusion Neuromuscular activity remains highly stable in elite skiers with low variability across four runs.
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Affiliation(s)
- Marine Alhammoud
- Aspetar–Orthopaedic and Sports Medicine Hospital, Doha, Qatar
- French Ski Federation, Annecy, France
- *Correspondence: Marine Alhammoud
| | - Olivier Girard
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, WA, Australia
| | - Clint Hansen
- Department of Neurology, Christian-Albrechts-Universität zu Kiel Medizinische Fakultat, Kiel, Germany
| | | | - Frédéric Meyer
- Digital Signal Processing Group, Department of Informatics, University of Oslo, Oslo, Norway
| | - Christophe André Hautier
- Inter-University Laboratory of Human Movement Biology, University Claude Bernard Lyon 1, Lyon, France
| | - Baptiste Morel
- Inter-University Laboratory of Human Movement Biology (EA 7424), Savoie Mont Blanc University, Chambéry, France
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12
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Geng Y, Wu X, Zhang L. Effects of Blood Flow Restriction Training on Blood Perfusion and Work Ability of Muscles in Elite Para-alpine Skiers. Med Sci Sports Exerc 2021; 54:489-496. [PMID: 34669671 PMCID: PMC8830888 DOI: 10.1249/mss.0000000000002805] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Purpose The effects of short-term blood flow restriction (BFR) exercise on muscle blood flow perfusion and performance during high-intensity exercise were determined in elite para-alpine standing skiers to assess whether this would be an effective training regimen for elite athletes with disabilities. Methods Nine national-level para-alpine standing skiers (mean age, 20.67 ± 1.34 yr; four women) were recruited. Nondominant lower limbs were trained with BFR (eight in final analyses), and dominant lower limbs were trained without BFR (seven in final analyses). The 2-wk protocol included high-load resistance, local muscle endurance (circuit resistance training), and aerobic endurance (stationary cycling) training performed 4 times a week, with BFR during local muscle endurance and aerobic endurance sessions. Muscle strength was measured by maximal voluntary isometric contraction (MVIC) in the knee extensors; microcirculatory blood perfusion (MBP), by laser Doppler blood flow; and muscle strength and endurance, by the total amount of work (TW) performed during high-intensity centrifugal and concentric contractions. Results BFR significantly increased absolute and relative MVIC (P < 0.001, P = 0.001), MBP (P = 0.011, P = 0.008), and TW (P = 0.006, P = 0.007) from pretraining values, whereas only absolute MVIC increased without BFR (P = 0.047). However, the MVIC increase with BFR exercise (35.88 ± 14.83 N·m) was significantly greater (P = 0.040) than without BFR exercise (16.71 ± 17.79 N·m). Conclusions Short-term BFR exercise significantly increased strength endurance, muscle strength, and MBP in national-level para-alpine standing skiers. Our study provides new evidence that BFR exercise can improve local muscle blood perfusion during high-intensity exercise and informs BFR exercise strategies for athletes with disabilities.
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Affiliation(s)
- Yu Geng
- School of Physical Education and Sport Training, Shanghai University of Sport, Shanghai, China Department of Physical Education, Jiyang College of Zhejiang A&F University, Zhejiang, China
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13
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Abstract
Maintaining euhydration is important for optimal health, performance and recovery, but can be challenging for alpine skiers when training in a relatively cold but dry environment. This study aimed to evaluate hydration status, fluid loss and fluid intake in adolescent alpine skiers during a training camp. Twelve athletes aged 14.3 ± 0.9 years volunteered to participate in the study. Athletes resided at an altitude of 1600 m and trained between 1614 and 2164 m. During eight consecutive days, urine specific gravity was measured before each morning training session using a refractometer. Changes in body weight representing fluid loss and ad libitum fluid intake during each morning training session were assessed using a precision scale. Mean pre-training urine specific gravity remained stable throughout the training camp. Individual values ranged between 1.010 and 1.028 g/cm3with 50 to 83% of athletes in a hypohydrated state (urine specific gravity ≥ 1.020 g/cm3). Mean training induced fluid loss remained stable throughout the training camp (range -420 to -587 g) with individual losses up to 1197 g (-3.5%). Fluid intake was significantly lower than fluid loss during each training session. To conclude, urine specific gravity values before training indicated insufficient daily fluid intake in more than half of the athletes. Furthermore, fluid intake during training in adolescent alpine skiers was suboptimal even when drinks were provided ad libitum. Coaches and athletes should be encouraged to carefully monitor hydration status and to ensure that alpine skiers drink sufficiently during and in between training sessions.
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14
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Nilsson R, Theos A, Lindberg AS, Ferguson RA, Malm C. Lack of Predictive Power in Commonly Used Tests for Performance in Alpine Skiing. Sports Med Int Open 2021; 5:E28-E36. [PMID: 34131582 PMCID: PMC8193913 DOI: 10.1055/a-1078-1441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 11/27/2019] [Indexed: 11/18/2022] Open
Abstract
Competitive alpine skiing is a complex sport that requires high physical and technical competence. Testing the physical status of athletes may be important to increase their ability to achieve elite sport-specific performance. This study aimed to investigate the predictive power of the national test battery of the Swedish Olympic Committee (Fysprofilen) and anthropometric variables in the prediction of competitive performance of elite alpine skiers, indicated by Fédération Internationale de Ski points. Data from fourteen Swedish elite female alpine skiers were analyzed using bivariate and multivariate statistical methods. Physiological test results and anthropometric data could not generate significant bivariate or multivariate models for prediction of competitive performance. Multivariate regression (R2) and prediction (Q2) models for Fédération Internationale de Ski Slalom and Giant Slalom rank reached R2=0.27 to 0.43, Q2=+− 0.8 to−0.17, indicating no valid models. The overall interpretation of these and previous findings are that future test batteries must be validated before implemented, and that test results should be treated with caution when it comes to prediction of future competitive results. Applying tests that are not validated against competitive performance risk misleading coaches and training advisors who aim to increase the sports-specific performance of the individual athlete.
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Affiliation(s)
- Robert Nilsson
- Department of Community Medicine and Rehabilitation, Section of Sports Medicine, Umeå University, Sweden
| | - Apostolos Theos
- Department of Community Medicine and Rehabilitation, Section of Sports Medicine, Umeå University, Sweden
| | - Ann-Sofie Lindberg
- Department of Community Medicine and Rehabilitation, Section of Sports Medicine, Umeå University, Sweden.,Winternet, Winternet, Boden, Sweden
| | - Richard A Ferguson
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom of Great Britain and Northern Ireland
| | - Christer Malm
- Department of Community Medicine and Rehabilitation, Section of Sports Medicine, Umeå University, Sweden
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15
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Reliability of Alpine Ski Racing-Specific Field Test: The 80s-Slide-Test. Int J Sports Physiol Perform 2021; 16:1545-1550. [PMID: 33883292 DOI: 10.1123/ijspp.2019-0696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/22/2020] [Accepted: 11/23/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE The purpose of this study was to determine the test-retest reliability of the 80s-slide-test in well-trained alpine ski racers. METHODS The sample consisted of 8 well-trained alpine ski racers (age = 17.8 [0.7] y old; height = 1.80 [0.09] m; body mass = 72.1 [9.5] kg) who performed a lab-based maximal graded test on cycle ergometer and three 80s-slide-tests in 4 separate sessions. The 80s-slide-test consisting of maximal push-offs performed for 80s on a 8-ft slide board. Oxygen uptake (V˙O2) and heart rate (HR) were recorded continuously. Blood lactate ([La]b) was determined immediately prerun, followed by 3 minutes postrun. Three minutes after the completion of the session, the subjects were asked to indicate their rate of perceived exertion using Borg scale ranging from 6 to 20. Total and every 10s mean push-offs number were assessed by camera. Typical errors of measurement, intraclass correlation coefficients, and smallest worthwhile change were calculated. RESULTS The 80s-slide-test showed strong reliability for total push-offs number, V˙O2peak, V˙O2mean, HRpeak, and HRmean. Δ[La]b, fatigue index, and the rate of perceived exertion were moderately reliable. CONCLUSION The 80s-slide-test is a reliable test for well-trained alpine ski racers and can be used easily by trainers.
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16
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Pritchard JJ. Fitness Testing Parameters for Alpine Ski Racing. Strength Cond J 2021. [DOI: 10.1519/ssc.0000000000000587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Comparing Active, Passive, and Combined Warm-Ups Among Junior Alpine Skiers in -7°C. Int J Sports Physiol Perform 2021; 16:1140–1147. [PMID: 33588374 DOI: 10.1123/ijspp.2020-0300] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 11/18/2022]
Abstract
CONTEXT Warming up in very cold climates and maintaining an elevated body temperature prior to a race is challenging for snow-sport athletes. PURPOSE To investigate the effects of active (ACT), passive (PAS), and a combination of ACT and PAS (COM) warm-ups on maximal physical performance in a subzero environment among snow-sport athletes. METHODS Ten junior alpine skiers completed 3 experimental trials in -7.2 (0.2)°C. The ACT involved 5 minutes of moderate cycling, 3 × 15-second accelerations, a 6-second sprint, 5 countermovement jumps (CMJs), and a 10-minute passive transition phase, while in PAS, participants wore a lower-body heated garment for 24 minutes. In COM, participants completed the active warm-up, then wore the heated garment during the transition phase. Two maximal CMJs and a 90-second maximal isokinetic cycling test followed the warm-up. RESULTS CMJ performance was likely (P = .150) and very likely (P = .013) greater in ACT and COM, respectively, versus PAS. Average power output during the cycling test was likely (P = .074) greater in ACT and COM versus PAS. Participants felt likely to almost certainly warmer (P < .01) and more comfortable (P = .161) during ACT and COM versus PAS. In addition, participants felt likely warmer (P = .136) and very likely more comfortable (P = .161) in COM versus ACT. CONCLUSIONS COM resulted in significantly improved CMJ performance versus PAS while both ACT and COM led to likely improved 90-second cycling performance. Participants felt significantly warmer during ACT and COM versus PAS and likely warmer in COM versus ACT. Therefore, a combined warm-up is recommended for alpine skiers performing in subzero temperatures.
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18
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Are There Associations Between Submaximal and Maximal Aerobic Power and International Ski Federation World Cup Ranking in Elite Alpine Skiers? Int J Sports Physiol Perform 2021; 16:628-633. [PMID: 33508781 DOI: 10.1123/ijspp.2020-0105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/11/2020] [Accepted: 05/31/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE To analyze the predictive value of parameters of submaximal and maximal cardiopulmonary exercise performance on International Ski Federation (Fédération Internationale de Ski) World Cup ranking (FIS ranking) in elite Austrian Alpine skiers. METHODS Over 7 World Cup seasons (2012-2018), exercise data (maximal oxygen uptake and maximum power output, lactate threshold 2, and ventilatory threshold 2, based on stepwise cycle spiroergometry) were analyzed to determine whether there was a correlation between world FIS ranking and exercise capacity of male and female elite Alpine skiers. RESULTS The data of 39 male skiers (age: 27.67 [4.20] y, body mass index: 26.03 [1.25] kg/m2) and 36 female skiers (age: 25.49 [3.18] y, body mass index: 22.97 [1.71] kg/m2) were included in this study. The maximum oxygen uptake and maximum power output ranged from 4.37 to 4.42 W/kg and 53.41 to 54.85 mL/kg/min in men and from 4.17 to 4.30 W/kg and 45.96 to 49.16 mL/kg/min in women, respectively, over the 7 seasons; the yearly mean FIS ranking ranged from 17 to 24 in men and 9 to 18 in women. In a fixed-effects model used for the subsequent panel regression analysis, no statistically significant effect on FIS ranking was found for the exercise parameters of interest. CONCLUSIONS Neither maximal aerobic tests nor maximum power output significantly predicted competitive performance, as indexed by the FIS ranking. This reinforces the assumption that no single parameter determines competition performance in this complex sport. Therefore, identifying the optimum amount of endurance training remains a major challenge for athletes and coaches, as does identifying and improving the factors that determine performance.
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19
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Changes in Anthropometric and Fitness Characteristics Over a Decade of Young Elite Alpine Ski Racers. Int J Sports Physiol Perform 2020; 16:124-134. [PMID: 33271508 DOI: 10.1123/ijspp.2019-0889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 02/06/2020] [Accepted: 03/09/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE The aim of this study was to evaluate whether anthropometric and fitness characteristics have changed between former and current elite male and female Austrian young ski racers (U11-U15). METHODS A battery of anthropometric, general, and skiing-specific fitness tests was conducted annually. In total, 1517 participants (846 males, 671 females) who were tested in 2005-2009 ("former athletes" n = 805) and 2015-2019 ("current athletes" n = 712) were included. Independent t tests and Cohen d were calculated to compare the two 5-y periods, separated by sex and age group. The level of significance was set at P < .05. RESULTS No significant change in anthropometric characteristics was found over the decade. Current young ski racers performed significantly better in the maximal core flexion strength test in all age categories (ES = 0.88-1.50; P < .02). Core extension strength values were higher in current male U12 and female U12 and U13 athletes (ES = 0.54-0.71; P < .01) and better postural stability values in the lateral direction were found in the age categories U12 and U14 (ES = 0.36-0.68; P < .05), as well as in the forward/backward direction in the age categories U12-U14 (ES = 0.38-1.12; P < .03). Lower-leg extension strength values were apparent in the current U13-U15 age categories (ES = 0.36-1.03; P ≤ .001) and lower drop-jump reactive strength indices in the U13-U15 male athletes (ES = 0.49-0.80; P < .01). CONCLUSIONS Current and former young ski racers differ significantly in some fitness parameters, which might lead to the assumption that some aspects (such as core strength) have gained more focus in athletic training during the last years compared with 15 y ago.
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20
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Cross MR, Rivière JR, Coulmy N, Morin JB, Samozino P. Lower limb force-production capacities in alpine skiing disciplines. Scand J Med Sci Sports 2020; 31:848-860. [PMID: 33259106 DOI: 10.1111/sms.13897] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/20/2020] [Accepted: 11/27/2020] [Indexed: 11/29/2022]
Abstract
Specific force capacities might be a limiting factor for alpine skiing performance, yet there is little consensus on the capabilities in question, and whether they differ between disciplines. We aimed to test discipline (speed and technical) and performance (event-specific world standing) effects on lower limb force-production qualities. National-level skiers (N = 31) performed loaded squat jumps and isometric mid-thigh pulls to detect dynamic force output at extremely low and high velocities and maximum isometric force and rate of force development, respectively. Discipline differences were assessed via a general linear model including performance and allowing for interaction effects, with performance associations further characterized via distinct Pearson's correlations. Jump height did not differentiate disciplines, with absolute power slightly higher in speed athletes (F(1,27) = 4.42, P = .045, ω2 = 0.10), and neither variables were related to performance. Speed athletes possessed greater dynamic force at low velocities (F0 ; F(1,27) = 13.8, P < .001, ω2 = 0.17), and greater relative and absolute maximum isometric force (F(1,25) = 11.19-20.70, ω2 = 0.16-0.22, P < .003). Overall, higher ranked athletes possessed more force-dominant profiles (F(1,27) = 16.28, ω2 = 0.34; r = 0.60 to 0.67, P < .001) and increased rate of force development characteristics (average and maximum, r = -0.50 to -0.82, P < .048). Very robust associations existed between maximum isometric force and speed performance (r = -0.88, P < .001), but only a trend for higher absolute isometric force in technical athletes (r = -0.49, P = .052). Alpine skiers display a preponderance for dynamic force output at low velocities, and isometric force for speed athletes, which highlights the interest in specific assessment and conditioning practices for ski athletes.
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Affiliation(s)
- Matthew R Cross
- Laboratoire Interuniversitaire de Biologie de la Motricité, Université Savoie Mont Blanc, Le Bourget du Lac, France.,Département Scientifique et Sportif, Fédération Française de Ski, Annecy, France.,Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, New Zealand
| | - Jean Romain Rivière
- Laboratoire Interuniversitaire de Biologie de la Motricité, Université Savoie Mont Blanc, Le Bourget du Lac, France
| | - Nicolas Coulmy
- Département Scientifique et Sportif, Fédération Française de Ski, Annecy, France
| | - Jean-Benoit Morin
- Sports Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, New Zealand.,Inter-university Laboratory of Human Movement Biology, Université Jean Monnet, Saint-Étienne, France
| | - Pierre Samozino
- Laboratoire Interuniversitaire de Biologie de la Motricité, Université Savoie Mont Blanc, Le Bourget du Lac, France
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21
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Ferland PM, Carey VD, Comtois AS. Validation of the alpine skiing 90 seconds box jump field test and prediction of power output. J Sports Med Phys Fitness 2020; 61:380-385. [PMID: 33140633 DOI: 10.23736/s0022-4707.20.11244-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The purpose of this study was to validate the alpine ski racing 90 s box jump field-test (BJ90) with the 90 s Wingate test (W90). METHODS Fifteen elite alpine ski racers were tested on the BJ90 (0.45 m × 0.75 m × 0.9 m) and the W90 (Ergomedic 894 E Monark; Monark AB, Varberg, Sweden) test in a random order. The number of hits on the BJ90 was written down every 15 s and for the W90 the load (7.5% of body weight) was manually dropped once the subjects reached maximum RPM without resistance. Correlations and partial correlations were calculated with a 2-tailed Pearson correlation analysis. A stepwise forward regression analysis was also performed. RESULTS Results present significant (P<0.05) correlations and partial correlations adjusted for body weight between the total number of hits on the BJ90 and W90 peak W, peak W/kg, mean W and mean W/kg as well as with the number of hits and W90 Mean W and mean W/kg between each 15 s time slot. A linear regression predictive equation for mean relative power (W/kg) generated from the BJ90 was established: mean relative power (W/kg)=0.055*total hits+1.080 (r=0.79, P<0.001; total hits with mean W/kg). A stepwise forward regression equation for mean absolute power (W) generated from the BJ90 was also established: mean absolute power (W)=2.305*number of hits+5.081*body weight in kg-1 -169.8 (R=0.964, P<0.001, SEE=23.56). CONCLUSIONS Practitioners could use the BJ90 to assess alpine skiers lower body power as previous research showed that both are correlated with performance and are able to discriminate skier level.
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Affiliation(s)
- Pierre-Marc Ferland
- Department of Exercise Science, University of Quebec in Montreal, Montreal, QC, Canada -
| | - Vincent D Carey
- Department of Exercise Science, University of Quebec in Montreal, Montreal, QC, Canada
| | - Alain S Comtois
- Department of Exercise Science, University of Quebec in Montreal, Montreal, QC, Canada
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22
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DeCouto BS, Fawver B, Taylor T, Williams AM. Physical fitness is associated with better technical performance in adolescent alpine ski racers after controlling for practice time: A retrospective regression analysis. J Sports Sci 2020; 39:380-387. [PMID: 32951530 DOI: 10.1080/02640414.2020.1823088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In an effort to evaluate the mechanisms underpinning performance in alpine ski racing, researchers have focused on the predictive validity of measures derived from fitness assessments. However, a limitation of this literature is the absence of practice time, since prolonged training may naturally develop specific fitness capacities, making some tests of physical ability less predictive of performance. We examine the relationship between fitness tests, practice, and performance using linear regressions with fitness test data, practice history data, and performance results from adolescent alpine ski racers attending professional development academies in the United States (N = 82). Only aerobic capacity (i.e. 20 m shuttle run) was significantly associated with more practice time. After controlling for practice hours, 5.5-6.5% of variance in ski performance was significantly explained by assessments of lower body power (i.e. standing long jump, triple jump), anaerobic capacity (i.e. 60 s box jump), and upper body strength/endurance (i.e. push-ups). Findings highlight the important role of anaerobic power on alpine ski racing performance, which may be developed outside of regular practice, possibly through weight training or physical maturation. The small variance explained by physical/physiological measures suggests that superior ski performance is likely a product of various skills and characteristics (e.g. technical, tactical, perceptual-cognitive, psychosocial).
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Affiliation(s)
- Brady S DeCouto
- Department of Health and Kinesiology, University of Utah, College of Health , Salt Lake City, UT, USA
| | - Brad Fawver
- Department of Health and Kinesiology, University of Utah, College of Health , Salt Lake City, UT, USA
| | - Troy Taylor
- United States Ski & Snowboard , Park City, UT, USA
| | - Andrew Mark Williams
- Department of Health and Kinesiology, University of Utah, College of Health , Salt Lake City, UT, USA
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23
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Jeon Y, Eom K. Role of physique and physical fitness in the balance of Korean national snowboard athletes. J Exerc Sci Fit 2020; 19:1-7. [PMID: 32904222 PMCID: PMC7452248 DOI: 10.1016/j.jesf.2020.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/16/2020] [Accepted: 07/01/2020] [Indexed: 11/12/2022] Open
Abstract
Background The objective of this study is to understand the relationship between physique, physical fitness, and balance performance for snowboard athletes. Methods We considered all Korean national snowboard athletes (n = 9 with 6 males and 3 females, age = 17.44 ± 4.42), who have an experience of competition at continental cup level, to measure their physique, physical fitness, and (both static and dynamic) balance. Static balance was evaluated based on one-legged standing, while dynamic balance was estimated using a stability platform. Results Static balance is strongly correlated (p < 0.05) with circumference of the left lower leg (34.49 ± 2.42 cm; ρ = 0.68), sit-up (57.56 ± 8.8; ρ = 0.72), sargent jump (50.22 ± 11.78 cm; ρ = 0.67), strength of bench press (39.11 ± 17.73 kg; ρ = 0.67), angle of left ankle dorsiflexion (73.78 ± 7.86°; ρ = 0.77), average extension strength at 180° for left knee (321 ± 63.95 %BW; ρ = 0.77) and right knee (337 ± 60.32 %BW; ρ = 0.77), and right knee peak flexion strength at 60° (148 ± 25.61 %BW; ρ = 0.73). Center dynamic balance is negatively correlated with circumference of the right lower leg (34.63 ± 2.38 cm; ρ = −0.67, p < 0.05), while right dynamic balance is positively correlated with left ankle flexion (148.44 ± 5.20°; ρ = 0.78, p < 0.05). Conclusion Static balance is related to core muscle endurance and power, ankle flexibility, and knee stability, while dynamic balance is negatively correlated with circumference of the most frequently used lower leg (i.e., the leg dominating the snowboarding stance). The relationship between physique, physical fitness, and balance provides an insight into improving the balance performance of elite snowboard athletes through a training program that can affect the physique and physical fitness factors related to balance.
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Affiliation(s)
- Youngirl Jeon
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Kilho Eom
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
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Alhammoud M, Hansen C, Meyer F, Hautier C, Morel B. On-Field Ski Kinematic According to Leg and Discipline in Elite Alpine Skiers. Front Sports Act Living 2020; 2:56. [PMID: 33345047 PMCID: PMC7739787 DOI: 10.3389/fspor.2020.00056] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 04/20/2020] [Indexed: 11/23/2022] Open
Abstract
This study used wireless technology to investigate joint kinematic characteristics of the four alpine skiing disciplines. Knee and hip angles were measured in 20 national team alpine skiers during 253 ski runs under FIS regulation, including: 85 Slalom (SL), 123 Giant Slalom (GS), 29 Super Giant Slalom (SG), and 16 Downhill (DH). Data were analyzed by outside (OL, n = 2,087) and inside leg (IL, n = 2,015). The proportion of concentric and eccentric phases (extension and flexion respectively for the knee extensors) as well as the proportion of the quasi-isometric phase defined between ±20°.s−1 depended on the discipline in interaction with the IL/OL (p < 0.001). The results showed a lower knee quasi-isometric duration on OL in SL (11%) than other disciplines (DH: 38%; SG: 42%; GS: 34%, p < 0.001, d > 1.8), suggesting a highly dynamic style. Quasi-isometric mode was significantly longer on OL than IL in GS (34 vs. 20%, p < 0.001, d = 1.16) and SG (42 vs. 28%, p < 0.001, d = 1.11) but was significantly longer on IL than OL in SL (19 vs. 11%, p < 0.001, d = 0.64). Thus, GS and SG showed similarities, with a significantly faster knee eccentric mean angular velocity on IL compared to OL (GS −58 vs. −54°.s−1, SG −52 vs. −45°.s−1, p < 0.001, d ≥ 0.22) whereas SL showed an opposite pattern (−72 vs. −89°.s−1, p < 0.001, d = 1.10). The quasi-isometric phase was overlooked in previous studies but is crucial to consider. The current data may be used to train the outside and inside leg specificities incorporating discipline-specific contraction modes and exercises.
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Affiliation(s)
- Marine Alhammoud
- French Ski Federation, Annecy, France.,Inter-University Laboratory of Human Movement Biology (EA 7424), University Claude Bernard Lyon 1, Lyon, France.,Surgery Department, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - Clint Hansen
- Department of Neurology, Christian-Albrechts-Universität zu Kiel Medizinische Fakultat, Kiel, Germany
| | - Frederic Meyer
- Institute of Sport Science, University of Lausanne, Lausanne, Switzerland
| | - Christophe Hautier
- Inter-University Laboratory of Human Movement Biology (EA 7424), University Claude Bernard Lyon 1, Lyon, France
| | - Baptiste Morel
- Laboratory "Movement, Interactions, Performance" (EA 4334), Le Mans University, Le Mans, France.,Inter-University Laboratory of Human Movement Biology (EA 7424), Savoie Mont Blanc University, Chambéry, France
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25
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Alhammoud M, Oksa J, Morel B, Hansen C, Chastan D, Racinais S. Thermoregulation and shivering responses in elite alpine skiers. Eur J Sport Sci 2020; 21:400-411. [DOI: 10.1080/17461391.2020.1754470] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Marine Alhammoud
- French Ski Federation, Annecy, France
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar
| | - Juha Oksa
- Workability and working Careers, Finnish Institute of Occupational Health, Oulu, Finland
| | - Baptiste Morel
- Inter-University Laboratory of Human Movement Biology (EA 7424), Savoie Mont-Blanc University, Chambéry, France
| | - Clint Hansen
- Department of Neurology, Christian-Albrechts-Universitat zu Kiel Medizinische Fakultat, Kiel, Germany
| | | | - Sebastien Racinais
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar
- Laboratory Sport, Expertise and Performance, French Institute of Sport (INSEP), Paris, France
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26
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Csapo R, Hoser C, Gföller P, Raschner C, Fink C. Fitness, knee function and competition performance in professional alpine skiers after ACL injury. J Sci Med Sport 2019; 22 Suppl 1:S39-S43. [DOI: 10.1016/j.jsams.2018.06.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/08/2018] [Accepted: 06/21/2018] [Indexed: 01/10/2023]
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27
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Vernillo G, Coulmy N, Millet GP. Editorial: Recent Evolutions and Perspectives in Olympic Winter Sports Performance: To PyeongChang and Beyond…. Front Physiol 2019; 10:481. [PMID: 31068839 PMCID: PMC6491754 DOI: 10.3389/fphys.2019.00481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/05/2019] [Indexed: 11/21/2022] Open
Affiliation(s)
- Gianluca Vernillo
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
- *Correspondence: Gianluca Vernillo
| | | | - Grégoire P. Millet
- Faculty of Biology and Medicine, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
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28
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Steidl-Müller L, Hildebrandt C, Raschner C, Müller E. Challenges of talent development in alpine ski racing: a narrative review. J Sports Sci 2019; 37:601-612. [PMID: 30676888 DOI: 10.1080/02640414.2018.1513355] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Alpine ski racing is one of the most popular sports in many countries; nevertheless, selection disadvantages and severe injuries result in high dropout rates. In this review we summarize existing knowledge about the specific challenges associated with selection bias and injuries, and their effects on talent development in ski racing. The relative age effect (RAE) appears in all age categories of national Austrian and international alpine ski racing. Relatively younger athletes seem to only have a chance for selection if they are early maturing. Talent selection processes should consider both the biological maturity status as well as the relative age; additionally, a competition system based on a rotating cut-off date might contribute to a reduction of RAE. Youth and adolescent ski racers report lower injury rates compared to World Cup athletes. The knee was the most affected body part in relation to traumatic injuries. The most frequently reported overuse injuries were knee pain (youth) and low back pain (adolescent level). Athlete-related modifiable risk factors were core strength, neuromuscular control, leg extension strength and limb asymmetries. Based on these findings, prevention measures should be expanded to contribute to long-term injury prevention. In future research more multi-disciplinary, longitudinal studies should be performed.
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Affiliation(s)
- Lisa Steidl-Müller
- a Department of Sport Science , University of Innsbruck , Innsbruck , Austria
| | - Carolin Hildebrandt
- a Department of Sport Science , University of Innsbruck , Innsbruck , Austria
| | - Christian Raschner
- a Department of Sport Science , University of Innsbruck , Innsbruck , Austria
| | - Erich Müller
- a Department of Sport Science , University of Innsbruck , Innsbruck , Austria
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Burtscher M, Federolf PA, Nachbauer W, Kopp M. Potential Health Benefits From Downhill Skiing. Front Physiol 2019; 9:1924. [PMID: 30692936 PMCID: PMC6340074 DOI: 10.3389/fphys.2018.01924] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 12/20/2018] [Indexed: 01/05/2023] Open
Abstract
Objectives: Downhill skiing represents one of the most popular winter sports worldwide. Whereas a plethora of studies dealt with the risk of injury and death associated with downhill skiing, data on its favorable health effects are scarce. A more comprehensive overview on such effects might emerge from a multidisciplinary perspective. Methods: A literature search has been performed to identify original articles on downhill/alpine skiing interventions or questionnaire-based evaluation of skiing effects and the assessment of health effects (cardiorespiratory, neurophysiological, musculoskeletal, psycho-social). Results and Discussion: A total of 21 original articles dealing with potentially favorable health effects resulting from downhill skiing were included in this review. Results indicate that downhill skiing, especially when performed on a regular basis, may contribute to healthy aging by its association with a healthier life style including higher levels of physical activity. Several other mechanisms suggest further favorable health effects of downhill skiing in response to specific challenges and adaptations in the musculo-skeletal and postural control systems, to exposures to cold temperatures and intermittent hypoxia, and/or emotional and social benefits from outdoor recreation. However, reliable data corroborating these mechanisms is scarce.
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Affiliation(s)
- Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Peter A Federolf
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Werner Nachbauer
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Martin Kopp
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
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30
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Gilgien M, Reid R, Raschner C, Supej M, Holmberg HC. The Training of Olympic Alpine Ski Racers. Front Physiol 2018; 9:1772. [PMID: 30622477 PMCID: PMC6308179 DOI: 10.3389/fphys.2018.01772] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 11/23/2018] [Indexed: 11/13/2022] Open
Abstract
Alpine combined was the only alpine ski racing event at the first Winter Olympic Games in 1936, but since then, slalom, giant slalom, super-G, downhill, and team events have also become Olympic events. Substantial improvements in slope preparation, design of courses, equipment, and the skills of Olympic alpine skiers have all helped this sport attain its present significance. Improved snow preparation has resulted in harder surfaces and improved equipment allows a more direct interaction between the skier and snow. At the same time, courses have become more challenging, with technical disciplines requiring more pronounced patterns of loading - unloading, with greater ground reaction forces. Athletes have adapted their training to meet these new demands, but little is presently known about these adaptations. Here, we describe how Olympic athletes from four of the major alpine ski racing nations prepared for the Olympic Games in South Korea in 2018. This overview describes their typical exercise programs with respect to physical conditioning, ski training and periodization, based on interviews with the coaching staff. Alpine ski racing requires mastery of a broad spectrum of physical, technical, mental, and social skills. We describe how athletes and teams deal with the multifactorial nature of the training required. Special emphasis is placed on sport-specific aspects, such as the combination of stimuli that interfere with training, training with chronic injury, training at altitude and in cold regions, the efficiency and effectiveness of ski training and testing, logistic challenges and their effects on fatigue, including the stress of frequent traveling. Our overall goal was to present as complete a picture of the training undertaken by Olympic alpine skiers as possible and on the basis of these findings propose how training for alpine ski racing might be improved.
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Affiliation(s)
- Matthias Gilgien
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
- Alpine Skiing, Norwegian Ski Federation, Oslo, Norway
| | - Robert Reid
- Alpine Skiing, Norwegian Ski Federation, Oslo, Norway
| | - Christian Raschner
- Department of Sport Science, Olympic Training Center, University of Innsbruck, Innsbruck, Austria
| | - Matej Supej
- Laboratory of Biomechanics, Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Hans-Christer Holmberg
- Swedish Winter Sports Research Centre, Mid Sweden University, Östersund, Sweden
- School of Sport Sciences, UiT The Arctic University of Norway, Tromsø, Norway
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
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31
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Thomas JA, A Perez-Alday E, Junell A, Newton K, Hamilton C, Li-Pershing Y, German D, Bender A, Tereshchenko LG. Vectorcardiogram in athletes: The Sun Valley Ski Study. Ann Noninvasive Electrocardiol 2018; 24:e12614. [PMID: 30403442 DOI: 10.1111/anec.12614] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/05/2018] [Accepted: 10/12/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Global electrical heterogeneity (GEH) is associated with sudden cardiac death (SCD) in adults of 45 years and above. However, GEH has not been previously measured in young athletes. The goal of this study was to establish a reference for vectorcardiograpic (VCG) metrics in male and female athletes. METHODS Skiers (n = 140; mean age 19.2 ± 3.5 years; 66% male, 94% white; 53% professional athletes) were enrolled in a prospective cohort. Resting 12-lead ECGs were interpreted per the International ECG criteria. Associations of age, sex, and athletic performance with GEH were studied. RESULTS In age and training level-adjusted analyses, male sex was associated with a larger T vector [T peak magnitude +186 (95% CI 106-266) µV] and a wider spatial QRS-T angle [+28.2 (17.3-39.2)°] as compared to women. Spatial QRS-T angle in the ECG left ventricular hypertrophy (LVH) voltage group (n = 21; 15%) and normal ECG group did not differ (67.7 ± 25.0 vs. 66.8 ± 28.2; p = 0.914), suggesting that ECG LVH voltage in athletes reflects physiological remodeling. In contrast, skiers with right ventricular hypertrophy (RVH) voltage (n = 26, 18.6%) had wider QRS-T angle (92.7 ± 29.6 vs. 66.8 ± 28.2°; p = 0.001), larger SAI QRST (194.9 ± 30.2 vs. 157.8 ± 42.6 mV × ms; p < 0.0001), but similar peak SVG vector magnitude (1976 ± 548 vs. 1939 ± 395 µV; p = 0.775) as compared to the normal ECG group. Better athletic performance was associated with the narrower QRS-T angle. Each 10% worsening in an athlete's Federation Internationale de' Ski downhill ranking percentile was associated with an increase in spatial QRS-T angle by 2.1 (95% CI 0.3-3.9) degrees (p = 0.013). CONCLUSION Vectorcardiograpic adds nuances to ECG phenomena in athletes.
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Affiliation(s)
- Jason A Thomas
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon.,Department of Biomedical Informatics and Medical Education, University of Washington, Seattle, Washington
| | - Erick A Perez-Alday
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon
| | - Allison Junell
- School of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Kelley Newton
- School of Medicine, Oregon Health and Science University, Portland, Oregon
| | - Christopher Hamilton
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon
| | - Yin Li-Pershing
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon
| | - David German
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon
| | - Aron Bender
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon
| | - Larisa G Tereshchenko
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon.,Johns Hopkins University School of Medicine, Baltimore, Maryland
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Ferland PM, Comtois AS. Athletic Profile of Alpine Ski Racers: A Systematic Review. J Strength Cond Res 2018; 32:3574-3583. [PMID: 30335713 DOI: 10.1519/jsc.0000000000002900] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ferland, PM and Comtois, AS. Athletic profile of alpine ski racers: a systematic review. J Strength Cond Res 32(12): 3591-3600, 2018-The purpose of this study was to review all anthropometric and physical test results performed on alpine ski racers that were published in the scientific literature to build an athletic profile specific to the skier's sex and level. Four electronic databases were systematically searched using the following key words: alpine, skiing, and physiology. The manual search was performed through the reference list of all suitable publications, the author's personal collection, and the proceedings of the International Congresses on Science and Skiing. The search and selection strategy permitted to gather data from 28 peer-reviewed publications that were collected on a total of 1,107 skiers coming from 11 different countries. Results of this study present the athletic profile and also review the different testing protocols. Findings show that men generally present higher test results than women and that higher-level ski racers generally present higher test results than lower-level ski racers. The present review should serve as guidelines for professionals working with alpine ski racers because most of the factors presented in the athletic profile have previously been shown to be related with performance. Further research should include more details on the testing protocols used, be directed toward female athletes, and present results from groups of athletes of the same sex and clearly identified as established at a certain level. These measures could help support further theoretical investigations.
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Affiliation(s)
- Pierre-Marc Ferland
- Department of Physical Activity Sciences, University of Quebec in Montreal, Montreal, Quebec, Canada
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Stöggl T, Kröll J, Helmberger R, Cudrigh M, Müller E. Acute Effects of an Ergometer-Based Dryland Alpine Skiing Specific High Intensity Interval Training. Front Physiol 2018; 9:1485. [PMID: 30405439 PMCID: PMC6200917 DOI: 10.3389/fphys.2018.01485] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 10/01/2018] [Indexed: 11/18/2022] Open
Abstract
Introduction: To establish an alpine ski racing (ASR) specific dryland high intensity training protocol (HIT), we set out to analyze cardiorespiratory and metabolic responses of three ASR specific HIT modes using a ski ergometer compared with a running HIT. Methods: Ten healthy international FIS level subjects (18 ± 1 years) performed an incremental running VO2max test, three different ASR specific HIT modes [slalom (SL), giant slalom (GS), and SL/GS mix] and a running HIT with measurements of VO2, heart rate (HR), blood lactate, and rate of perceived exertion (RPE). The HIT protocols included 15 × 1-min intervals with >90% HRmax and 30 s active rest. Furthermore, one elite alpine skier performed an 8-week, 17 session HIT block using the SL/GS mixed mode. Results: Running HIT resulted in greater VO2peak and whole-body RPE compared with the three ASR-specific HIT modes. During all four exercise modes participants were able to reach exercise intensities high enough to be classified as HIT (>90% HRmax and >89% VO2max). Legs RPE was similar between the four HIT modes, while arms RPE was higher for the ski-specific HIT. For all studied parameters, similar results for the three skiing specific HIT modes were observed. The 8-week HIT block was feasible for the athlete and resulted in an 11% increase in VO2max at unchanged peak power output. Conclusion: Across all HIT protocols high cardiorespiratory and metabolic responses were achieved. Therefore, the ASR specific HIT was shown to be feasible, thus could offer new possibilities for endurance training in elite alpine skiers. It is suggested to use the SL/GS mixed mode in terms of movement variety. The reduced VO2 in the ski-specific modifications can be attributed to the concentric and eccentric muscle activity resulting in mechanical hindrance for O2 extraction. The long-term effectiveness of ASR specific HIT in elite alpine skiers needs to be proven in a future study.
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Affiliation(s)
- Thomas Stöggl
- Department of Sport and Exercise Science, University of Salzburg, Salzburg, Austria
| | - Josef Kröll
- Department of Sport and Exercise Science, University of Salzburg, Salzburg, Austria.,Olympic Training Center Salzburg-Rif, Salzburg, Austria
| | - Roland Helmberger
- Department of Sport and Exercise Science, University of Salzburg, Salzburg, Austria
| | - Maria Cudrigh
- Olympic Training Center Salzburg-Rif, Salzburg, Austria
| | - Erich Müller
- Department of Sport and Exercise Science, University of Salzburg, Salzburg, Austria.,Olympic Training Center Salzburg-Rif, Salzburg, Austria
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Supej M, Nedergaard NJ, Nord J, Holmberg HC. The impact of start strategy on start performance in alpine skiing exists on flat, but not on steep inclines. J Sports Sci 2018; 37:647-655. [PMID: 30317917 DOI: 10.1080/02640414.2018.1522698] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Here, we explored the relationship between incline and start strategy during alpine skiing. Eight FIS skiers performed starts on a flat (3°) and steep (21°) incline employing five different strategies. Their times, trajectories and velocities were monitored with a GNSS system and video. A significant interaction was observed between slope incline and start strategy with respect to the skier's exit velocity (p < 0.001, ƞ2p = 0.716), but not for the start section time (p = 0.732, ƞ2p = 0.037). On the almost flat incline, both section time (p = 0.022, ƞ2p = 0.438) and exit velocity (p < 0.001, ƞ2p = 0.786) were influenced significantly by start strategy, with four V2 skate-pushes being optimal. On the steep incline, neither section time nor exit velocity was affected significantly by start strategy, the fastest section time and exit velocity being attained with four and two V2 skate-pushes, respectively. In conclusion, these findings demonstrate that the start strategy exerts considerable impact on start performance on almost flat inclines, with strategies involving three or more V2 skate-pushes being optimal. In contrast, start performance on the steep incline was not influenced by strategy.
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Affiliation(s)
- Matej Supej
- a Faculty of Sport , University of Ljubljana , Ljubljana , Slovenia.,b Swedish Winter Sports Research Centre , Mid Sweden University , Östersund , Sweden
| | - Niels J Nedergaard
- b Swedish Winter Sports Research Centre , Mid Sweden University , Östersund , Sweden.,c Department of Rehabilitation Sciences , KU Leuven , Leuven , Belgium
| | - Joakim Nord
- b Swedish Winter Sports Research Centre , Mid Sweden University , Östersund , Sweden.,d Swedish Ski Association , Åre , Sweden
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Steidl-Müller L, Hildebrandt C, Müller E, Fink C, Raschner C. Limb symmetry index in competitive alpine ski racers: Reference values and injury risk identification according to age-related performance levels. JOURNAL OF SPORT AND HEALTH SCIENCE 2018; 7:405-415. [PMID: 30450248 PMCID: PMC6230217 DOI: 10.1016/j.jshs.2018.09.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/23/2018] [Accepted: 05/10/2018] [Indexed: 05/27/2023]
Abstract
PURPOSE The aims of this study were to assess differences of limb symmetry index (LSI) in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related performance levels and to prospectively assess limb differences as a possible risk factor for traumatic and overuse injury in youth ski racers. METHODS The study (Study 1) included 285 high-level competitive ski racers (125 females, 160 males) of 3 age-related performance levels and based on the school system: 95 youth (10-14 years, secondary modern school), 107 adolescent (15-19 years, grammar school), and 83 elite athletes (20-34 years). To investigate the second aim (Study 2), 67 of the 95 youth athletes were included and any traumatic or overuse injuries were prospectively recorded over 2 seasons. All athletes performed 4 unilateral tests (strength related: one-leg counter movement jump (OL-CMJ) and one-leg isometric/isokinetic press strength test (OL-ILS); coordination related: one-leg stability test (OL-ST) and one-leg speedy jump test (OL-SJ)). The LSI was calculated by dividing the dominant leg by the nondominant leg and multiplying by 100. Kruskal-Wallis H tests and binary logistic regression analyses were conducted. RESULTS There were significant differences between the LSI of the 3 age-related performance-level groups only in the strength-related tests: the OL-CMJ (χ²(2, 285) = 9.09; p = 0.01) and the OL-ILS (χ²(2, 285) = 14.79; p < 0.01). The LSI for OL-ILS was found to be a significant risk factor for traumatic injury in youth ski racers (Wald = 7.08; p < 0.01). No significant risk factors were found for overuse injuries. CONCLUSION Younger athletes display slightly greater LSI values only in the strength-related tests. The cut-off value of limb differences of <10% for return to sport decisions seems to be appropriate for elite athletes, but for youth and adolescent athletes it has to be critically discussed. It seems to be necessary to define thresholds based on specific performance tasks (strength vs. coordination related) rather than on generalizations, and age-related performance levels must be considered. Limb differences in unilateral leg extension strength represent a significant injury risk factor in youth ski racers.
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Affiliation(s)
- Lisa Steidl-Müller
- Department of Sport Science, University of Innsbruck, Innsbruck 6020, Austria
| | - Carolin Hildebrandt
- Department of Sport Science, University of Innsbruck, Innsbruck 6020, Austria
| | - Erich Müller
- Department of Sport Science and Kinesiology, University of Salzburg, Salzburg 5400, Austria
| | - Christian Fink
- Research Unit for Orthopedic Sports Medicine and Injury Prevention, Institute of Psychology (ISAG), The Health & Life Sciences University (UMIT), Innsbruck 6020, Austria
- Gelenkpunkt – Sports and Joint Surgery, Innsbruck 6020, Austria
| | - Christian Raschner
- Department of Sport Science, University of Innsbruck, Innsbruck 6020, Austria
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Nilsson R, Lindberg AS, Theos A, Ferguson RA, Malm C. Aerobic Variables for Prediction of Alpine Skiing Performance - A Novel Approach. Sports Med Int Open 2018; 2:E105-E112. [PMID: 30539126 PMCID: PMC6277242 DOI: 10.1055/a-0655-7249] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/05/2018] [Accepted: 06/07/2018] [Indexed: 11/05/2022] Open
Abstract
The aim of this study was to investigate the predictive power of aerobic test results and anthropometric variables on FIS-ranking of junior elite alpine skiers. Results from twenty-three male and female adolescent elite alpine skiers from two seasons were included in the multivariate statistical models. Physical work capacity was determined by V̇O2peak, blood lactate concentration ([HLa]b), and heart rate (HR) during ergometer cycling. Anthropometric variables were body stature, body weight and calculated BMI. No significant correlation between competitive performance and aerobic work capacity or anthropometric data was observed neither in male nor female adolescent skiers. Pre-season physical tests and anthropometric data could therefore not predict end-season FIS-ranking. The best regression (R2) and prediction (Q2) models of FIS slalom (SL) and giant slalom (GS) rank reached R2=0.51 to 0.86, Q2=−0.73 to 0.18, indicating no valid models. This study could not establish V̇O2peak and other included variables as predictors of competitive performance. When combining results from commonly used tests for alpine skiers, and applying multivariate statistical models, investigated tests seems of limited used for athletes, coaches, and ski federations. Performance-specific pre-season tests must be developed and validated for prediction of performance and guidance of exercise training.
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Affiliation(s)
- Robert Nilsson
- Department of Community Medicine and Rehabilitation, Sports Medicine Unit, Umea University, Umeå, Sweden
| | | | - Apostolos Theos
- Department of Community Medicine and Rehabilitation, Sports Medicine Unit, Umea University, Umeå, Sweden
| | - Richard A Ferguson
- School of Sport, Exercise and Health Sciences, Loughborough University School of Sport Exercise and Health Sciences, Loughborough, United Kingdom of Great Britain and Northern Ireland
| | - Christer Malm
- Department of Community Medicine and Rehabilitation, Sports Medicine Unit, Umea University, Umeå, Sweden
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Vitale JA, La Torre A, Banfi G, Bonato M. Effects of an 8-Week Body-Weight Neuromuscular Training on Dynamic Balance and Vertical Jump Performances in Elite Junior Skiing Athletes: A Randomized Controlled Trial. J Strength Cond Res 2018; 32:911-920. [PMID: 29401197 DOI: 10.1519/jsc.0000000000002478] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Vitale, JA, La Torre, A, Banfi, G, and Bonato, M. Effects of an 8-week body-weight neuromuscular training on dynamic balance and vertical jump performances in elite junior skiing athletes: a randomized controlled trial. J Strength Cond Res 32(4): 911-920, 2018-The aim of the present randomized controlled trial was to evaluate the effects of an 8-week neuromuscular training program focused on core stability, plyometric, and body-weight strengthening exercises on dynamic postural control and vertical jump performance in elite junior skiers. Twenty-four Italian elite junior male skiers were recruited and randomized to either an experimental group (EG), performing neuromuscular warm-up exercises, (EG; n = 12; age 18 ± 1 years; body mass 66 ± 21 kg; height 1.70 ± 0.1 m) or a control group (CG) involved in a standard warm-up (CG; n = 12; age 18 ± 1 years; body mass 62 ± 14 kg; height 1.73 ± 0.1 m). lower quarter Y-Balance Test (YBT), countermovement jump (CMJ), and drop jump (DJ) at baseline (PRE) and at the end (POST) of the experimental procedures were performed. No significant differences between EG and CG were observed at baseline. Results showed that EG achieved positive effects from PRE to POST measures in the anterior, posteromedial, posterolateral directions, and composite score of YBT for both lower limbs, whereas no significant differences were detected for CG. Furthermore, 2-way analysis of variance with Bonferroni's multiple comparisons test did not reveal any significant differences in CMJ and DJ for both EG and CG. The inclusion of an 8-week neuromuscular warm-up program led to positive effects in dynamic balance ability but not in vertical jump performance in elite junior skiers. Neuromuscular training may be an effective intervention to specifically increase lower limb joint awareness and postural control.
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Affiliation(s)
- Jacopo A Vitale
- Laboratory of Biological Structure Mechanics, IRCCS Galeazzi Orthopedic Institute, Milano, Italy
| | - Antonio La Torre
- Laboratory of Biological Structure Mechanics, IRCCS Galeazzi Orthopedic Institute, Milano, Italy.,Department of Biomedical Sciences for Health, University of Milan, Milano, Italy
| | - Giuseppe Banfi
- Vita-Salute San Raffaele University, Milano, Italy.,Laboratory of Experimental Biochemistry & Molecular Biology, IRCCS Galeazzi Orthopedic Institute, Milano, Italy
| | - Matteo Bonato
- Department of Biomedical Sciences for Health, University of Milan, Milano, Italy
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Alhammoud M, Morel B, Girard O, Racinais S, Sevrez V, Germain A, Chamu T, Hautier C. Hypoxia and Fatigue Impair Rapid Torque Development of Knee Extensors in Elite Alpine Skiers. Front Physiol 2018; 9:962. [PMID: 30140231 PMCID: PMC6094991 DOI: 10.3389/fphys.2018.00962] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 06/29/2018] [Indexed: 01/20/2023] Open
Abstract
This study examined the effects of acute hypoxia on maximal and explosive torque and fatigability in knee extensors of skiers. Twenty-two elite male alpine skiers performed 35 maximal, repeated isokinetic knee extensions at 180°s-1 (total exercise duration 61.25 s) in normoxia (NOR, FiO2 0.21) and normobaric hypoxia (HYP, FiO2 0.13) in a randomized, single-blind design. Peak torque and rate of torque development (RTD) from 0 to 100 ms and associated Vastus Lateralis peak EMG activity and rate of EMG rise (RER) were determined for each contraction. Relative changes in deoxyhemoglobin concentration of the VL muscle were monitored by near-infrared spectroscopy. Peak torque and peak EMG activity did not differ between conditions and decreased similarly with fatigue (p < 0.001), with peak torque decreasing continuously but EMG activity decreasing significantly after 30 contractions only. Compared to NOR, RTD, and RER values were lower in HYP during the first 12 and 9 contractions, respectively (both p < 0.05). Deoxyhemoglobin concentration during the last five contractions was higher in HYP than NOR (p = 0.050) but the delta between maximal and minimal deoxyhemoglobin for each contraction was similar in HYP and NOR suggesting a similar muscle O2 utilization. Post-exercise heart rate (138 ± 24 bpm) and blood lactate concentration (5.8 ± 3.1 mmol.l-1) did not differ between conditions. Arterial oxygen saturation was significantly lower (84 ± 4 vs. 98 ± 1%, p < 0.001) and ratings of perceived exertion higher (6 ± 1 vs. 5 ± 1, p < 0.001) in HYP than NOR. In summary, hypoxia limits RTD via a decrease in neural drive in elite alpine skiers undertaking maximal repeated isokinetic knee extensions, but the effect of hypoxic exposure is negated as fatigue develops. Isokinetic testing protocols for elite alpine skiers should incorporate RTD and RER measurements as they display a higher sensitivity than peak torque and EMG activity.
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Affiliation(s)
- Marine Alhammoud
- Inter-university Laboratory of Human Movement Biology (EA 7424), Claude Bernard University Lyon 1, Lyon, France.,French Ski Federation, Annecy, France
| | - Baptiste Morel
- Laboratory "Movement, Interactions, Performance" (EA 4334), Le Mans University, Le Mans, France
| | - Olivier Girard
- School of Psychology and Exercise Science, Murdoch University, Perth, WA, Australia.,Athlete Health and Performance Research Centre, Aspetar Orthopedic and Sports Medicine Hospital, Doha, Qatar
| | - Sebastien Racinais
- Athlete Health and Performance Research Centre, Aspetar Orthopedic and Sports Medicine Hospital, Doha, Qatar.,Laboratory Sport, Expertise and Performance, French Institute of Sport (INSEP), Paris, France
| | - Violaine Sevrez
- French National Center for Scientific Research, Institute of Movement Sciences, Aix-Marseille University, Marseille, France
| | | | - Thomas Chamu
- Orthopedic and Sports Medicine Hospital La Sauvegarde, Lyon, France
| | - Christophe Hautier
- Inter-university Laboratory of Human Movement Biology (EA 7424), Claude Bernard University Lyon 1, Lyon, France
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39
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Vernillo G, Pisoni C, Thiébat G. Physiological and Physical Profile of Snowboarding: A Preliminary Review. Front Physiol 2018; 9:770. [PMID: 29973888 PMCID: PMC6019472 DOI: 10.3389/fphys.2018.00770] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 06/01/2018] [Indexed: 11/16/2022] Open
Abstract
The sport of snowboarding has grown in popularity as both a recreational winter activity as well as a prominent Olympic sport. Both forms are comprised of one of three different disciplines within the sport: freestyle, alpine, and snowboard-cross. In recent years, the increased professionalism and substantial growth of snowboarding as a global sport has increasingly attracted the interest of exercise physiologists and sport scientists. Given the small (but growing) number of studies that have been published, the research analyzing the physiological and performance characteristics and requirements of snowboarding remains limited. The absence of such studies signifies a lack of examination into this important but under-explored area of research, which could contribute valuable information to the scientific community and international snowboarding teams. The studies conducted thus far have indicated different requirements of physiological and physical traits dependent upon the specific discipline of snowboarding in question. For example, in order to meet the divers demands of each discipline, athletes must develop various qualities, such as muscular strength and power. This can increase their ability to withstand the high forces and loads on the muscular system during competition, and further decrease their risk of lower limbs injuries. At the same time, the studies acknowledge the potential advantages of aerobic fitness in terms of recovery, to more efficiently sustain the athlete through both competitive and on- and off-snow training sessions. Given the value and breadth of application of these limited studies, further analysis and research could contribute greater knowledge and benefits to the field of snowboarding. Therefore, it is the purpose of this preliminary review to explore the current literature, providing further insight into the physiological and physical demands of snowboarding performance. This preliminary review is intended to stimulate interest among the communities of exercise physiologists, sport scientists and particularly coaches in order to improve our current understanding of snowboarding and its demands as a sport. This preliminary review further seeks to develop protocols and strategies to assess physiological and performance characteristics of snowboarding, monitor athletic performance, provide practical recommendations for training, identify new areas of scientific research, and develop accurate talent identification programs.
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Affiliation(s)
- Gianluca Vernillo
- Department of Biomedical Sciences for Health, University of Milan, Milan, Milan.,Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, AB
| | - Cesare Pisoni
- Snowboard and Freestyle Sector, Italian Winter Sports Federation, Milan, Milan
| | - Gabriele Thiébat
- Snowboard and Freestyle Sector, Italian Winter Sports Federation, Milan, Milan.,Sports Trauma Centre, IRCCS Institute Orthopedic Galeazzi, Milan, Milan
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40
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Gilgien M, Kröll J, Spörri J, Crivelli P, Müller E. Application of dGNSS in Alpine Ski Racing: Basis for Evaluating Physical Demands and Safety. Front Physiol 2018; 9:145. [PMID: 29559918 PMCID: PMC5845727 DOI: 10.3389/fphys.2018.00145] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 02/13/2018] [Indexed: 12/05/2022] Open
Abstract
External forces, such as ground reaction force or air drag acting on athletes' bodies in sports, determine the sport-specific demands on athletes' physical fitness. In order to establish appropriate physical conditioning regimes, which adequately prepare athletes for the loads and physical demands occurring in their sports and help reduce the risk of injury, sport-and/or discipline-specific knowledge of the external forces is needed. However, due to methodological shortcomings in biomechanical research, data comprehensively describing the external forces that occur in alpine super-G (SG) and downhill (DH) are so far lacking. Therefore, this study applied new and accurate wearable sensor-based technology to determine the external forces acting on skiers during World Cup (WC) alpine skiing competitions in the disciplines of SG and DH and to compare these with those occurring in giant slalom (GS), for which previous research knowledge exists. External forces were determined using WC forerunners carrying a differential global navigation satellite system (dGNSS). Combining the dGNSS data with a digital terrain model of the snow surface and an air drag model, the magnitudes of ground reaction forces were computed. It was found that the applied methodology may not only be used to track physical demands and loads on athletes, but also to simultaneously investigate safety aspects, such as the effectiveness of speed control through increased air drag and ski-snow friction forces in the respective disciplines. Therefore, the component of the ground reaction force in the direction of travel (ski-snow friction) and air drag force were computed. This study showed that (1) the validity of high-end dGNSS systems allows meaningful investigations such as characterization of physical demands and effectiveness of safety measures in highly dynamic sports; (2) physical demands were substantially different between GS, SG, and DH; and (3) safety-related reduction of skiing speed might be most effectively achieved by increasing the ski-snow friction force in GS and SG. For DH an increase in the ski-snow friction force might be equally as effective as an increase in air drag force.
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Affiliation(s)
- Matthias Gilgien
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
- St. Moritz Health and Innovation Foundation, Center of Alpine Sports Biomechanics, St. Moritz, Switzerland
| | - Josef Kröll
- Department of Sport Science and Kinesiology, University of Salzburg, Hallein, Austria
| | - Jörg Spörri
- Department of Sport Science and Kinesiology, University of Salzburg, Hallein, Austria
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Philip Crivelli
- Group for Snowsports, WSL - Institute for Snow and Avalanche Research SLF, Davos, Switzerland
| | - Erich Müller
- Department of Sport Science and Kinesiology, University of Salzburg, Hallein, Austria
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Vitale JA, Lombardi G, Cavaleri L, Graziani R, Schoenhuber H, Torre AL, Banfi G. Rates of insufficiency and deficiency of vitamin D levels in elite professional male and female skiers: A chronobiologic approach. Chronobiol Int 2017; 35:441-449. [PMID: 29231753 DOI: 10.1080/07420528.2017.1410828] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Vitamin D is essential for the maintenance and promotion of musculoskeletal health, for the functioning of the immune, cardiovascular and reproductive systems, and its main action is to keep calcium and phosphate plasmatic physiological concentrations at intestinal, renal and bony level. Vitamin D affects several parameters related to physical performance too and a particularly high percentage of vitamin D insufficiency and deficiency in professional athletes has been observed. Several variables are able to impair the synthesis of 25(OH)D in athletes, specifically both genetic and environmental factors, but the most probable explanation for the deficient/insufficient vitamin D levels is the insufficient ultraviolet B light (UVB) exposure during winter. To confirm this, the existence of a circannual rhythm of vitamin D in professional soccer players, highlighting a peak in summer and lowest values in winter regardless the period of the season, has been documented. Nonetheless, from what we are aware of, no other study adopted a chronobiologic approach to better understand and describe the circannual variations of serum 25(OH)D in other sport disciplines. Therefore, we studied serum vitamin D in a cohort of top-level professional skiers, during a period of three consecutive competitive seasons (2015, 2016 and 2017), in order to evaluate, with a rhythmometric approach, the vitamin D behavior along the year. The study population was composed by 152 professional Italian alpine skiers of FISI (Winter Sport Italian Federation), 63 females and 89 males (mean age: 24.1 ± 3.2 years) and a total of 298 blood drawings were carried out to determine plasma 25(OH)D. Vitamin D data were compared between genders and then processed with the population mean cosinor tests to evaluate the presence of a circannual rhythm, both for female and male athletes. In total, 77 skiers (50.7%) showed, at least once during the three competitive seasons, an insufficient level of 25(OH)D and other 45 subjects (29.6%) showed a deficient status; no differences were observed between genders (mean for females: 26.9 ± 8.1 ng/mL; mean for males: 27.4 ± 7.6 ng/mL). In addition, the rhythmometric analysis highlighted the existence of a significant circannual rhythm for both female and male professional skiers; the acrophases (Φ) occurred in July and both MESOR (M) and amplitude (A) were comparable between the two groups. Our data indicate that, despite the physical effort spent, vitamin D follows a classical season-associated rhythm with a peak in summer and a nadir in winter. Moreover, the percentage of insufficiency and deficiency is in line with that of the general population. In conclusion, our findings reinforce the hypothesis that there is no direct effect of physical activity on vitamin D metabolism and that the factors involved in the determination of vitamin D levels in the general population are valid also for athletes.
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Affiliation(s)
- Jacopo Antonino Vitale
- a Laboratory of Biological Structure Mechanics , IRCCS Istituto Ortopedico Galeazzi , Milano , Italia
| | - Giovanni Lombardi
- b Laboratory of Experimental Biochemistry & Molecular Biology , IRCCS Istituto Ortopedico Galeazzi , Milano , Italia
| | - Luca Cavaleri
- c Department of Biomedical Sciences for Health , Università degli Studi di Milano , Milan , Italia
| | - Rosa Graziani
- d Centro Diagnostico Alto-Lombardo (CEDAL) , Gallarate , Italia
| | - Herbert Schoenhuber
- e Sports Traumatology and Arthroscopic Surgery Unit , IRCCS Istituto Ortopedico Galeazzi , Milano , Italia
| | - Antonio La Torre
- c Department of Biomedical Sciences for Health , Università degli Studi di Milano , Milan , Italia
| | - Giuseppe Banfi
- b Laboratory of Experimental Biochemistry & Molecular Biology , IRCCS Istituto Ortopedico Galeazzi , Milano , Italia.,f Vita-Salute San Raffaele University , Milano , Italia
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Raschner C, Hildebrandt C, Mohr J, Müller L. Sex Differences in Balance Among Alpine Ski Racers: Cross-Sectional Age Comparisons. Percept Mot Skills 2017; 124:1134-1150. [DOI: 10.1177/0031512517730730] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although balance is a key ability in the strength demands of alpine ski racing, affecting both performance and injury prevention, few studies have examined balance or related sex differences among still-maturing athletes. In this 10-year study, we investigated cross-sectional balance performances at different age periods of a representative sample of over 500 11–18-year-old elite skiers of both genders. Participants performed balance tests using the MFT S3-Check. Left–right and forward–backward movements were used to calculate sensory and symmetry balance scores, which were both incorporated into a stability score. Mann–Whitney U tests assessed gender-specific differences by age-group with a significance level set at p < .05. Results showed gender differences only on forward–backward measurements for 14–16-year-olds, with females showing better stability and sensory (but not symmetry) scores than males. Thus, gender interacted with age and maturation to influence balance ability in these participants. Additionally, these rare 10-year data support coaches in their training and talent development of maturing athletes by providing important sport-, age-, and gender-specific normative comparison data for individual trainees.
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Affiliation(s)
- Christian Raschner
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | | | - Johanna Mohr
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Lisa Müller
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
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Lesnik B, Sekulic D, Supej M, Esco MR, Zvan M. Balance, Basic Anthropometrics and Performance in Young Alpine Skiers; Longitudinal Analysis of the Associations During two Competitive Seasons. J Hum Kinet 2017; 57:7-16. [PMID: 28713454 PMCID: PMC5504574 DOI: 10.1515/hukin-2017-0042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Balance is hypothesized to be important in alpine skiing, while it is known that balance depends on anthropometric indices. The aim of this investigation was to explore the association between balance, anthropometrics and skiing-results over two competitive seasons among youth alpine-skiers. Eighty-one skiers (40 females) participated in this study. The participants were tested twice over two competitive seasons: when they were 12-13 years old (U14) and when they were 14-15 years old (U16). The variables consisted of anthropometrics (body height and body mass) and three balance indexes (medio-lateral-, anterio-posterior- and overall-stability-index). Additionally, skiing results in U14 and U16 were evaluated. The balance status did not change significantly over the observed period of time regardless of the significant changes in body mass and height. The relationships between balance and skiing results were higher in the U14 (Pearson’s r = 0.45-0.54) than in the U16 (Pearson’s r = 0.05-0.28). The relationships between anthropometrics and competitive results were generally stronger in girls (Pearson’s r = 0.39-0.88) than in boys (Pearson’s r = 0.26-0.58). After clustering athletes into three achievement groups on a basis of their competitive performance, discriminant canonical analysis showed that relationships between balance and skiing results decreased, while the relationships between anthropometrics and skiing results increased over the two observed seasons. This study highlighted the importance of balance in youth alpine skiing in the age range of 11-14 years.
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Affiliation(s)
- Blaz Lesnik
- University of Ljubljana, Faculty of Sport, Ljubljana, Slovenia
| | - Damir Sekulic
- University of Split, Faculty of Kinesiology, Split, Croatia.,University of Split, University Department of Health Care Studies, Split, Croatia
| | - Matej Supej
- University of Ljubljana, Faculty of Sport, Ljubljana, Slovenia
| | - Michael R Esco
- University of Alabama, Department of Kinesiology, Tuscaloosa, AL, USA
| | - Milan Zvan
- University of Ljubljana, Faculty of Sport, Ljubljana, Slovenia
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Fasel B, Sporri J, Chardonnens J, Kroll J, Muller E, Aminian K. Joint Inertial Sensor Orientation Drift Reduction for Highly Dynamic Movements. IEEE J Biomed Health Inform 2017; 22:77-86. [PMID: 28141537 DOI: 10.1109/jbhi.2017.2659758] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Inertial sensor drift is usually corrected on a single-sensor unit level. When multiple sensor units are used, mutual information from different units can be exploited for drift correction. This study introduces a method for a drift-reduced estimation of three dimensional (3-D) segment orientations and joint angles for motion capture of highly dynamic movements as present in many sports. 3-D acceleration measured on two adjacent segments is mapped to the connecting joint. Drift is estimated and reduced based on the mapped accelerations' vector orientation differences in the global frame. Algorithm validity is assessed on the example of alpine ski racing. Shank, thigh, and trunk inclination as well as knee and hip flexion were compared to a multicamera-based reference system. For specific leg angles and trunk segment inclination mean accuracy and precision were below 3.9° and 6.0°, respectively. The errors were similar to errors reported in other studies for lower dynamic movements. Drift increased axis misalignment and mainly affected joint and segment angles of highly flexed joints such as the knee or hip during a ski turn.
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45
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Abstract
Background/Objective To measure the cardiorespiratory and metabolic variables during the giant slalom (GS) skiing activity under actual race conditions using a mobile gas analyzer. Methods This study included 20 voluntary male alpine ski racers (mean age, 22.00 ± 1.45 years) who participated in international races. First, incremental running test was conducted to obtain volunteers' maximal oxygen consumption (VO2max) values. Second, respiratory data were measured during their performance on the GS course. Before both GS performance and incremental running test and at 1 minute, 3 minutes, and 5 minutes after the tests, blood lactate concentration was measured. Results VO2max values of the volunteers were 51.36 ± 2.68 mL/kg/min and they used 74.96% of this during their performance on the GS course. Their blood lactate concentrations reached the maximum level of 13.69 ± 2.06 mmol/L at the 5th minute following the maximal exercise testing. After the GS performance, blood lactate values reached the maximum level of 10.13 ± 0.43 mmol/L at the 3rd minute. While the maximum heart rate was 196.5 ± 4.3 bpm during the maximal exercise testing, it reached 201.7 ± 20 bpm during the GS performance. Conclusion It is observed that the GS race is a high-intensity activity and that high amount of anaerobic contribution is used by alpine ski racers during the GS race. By contrast, it is understood that the aerobic contribution is also at a considerable level during such an anaerobic activity as GS.
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Affiliation(s)
- Metin Polat
- Department of Coaching Education, Erciyes University, School of Physical Education and Sport, Kayseri, Turkey
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Müller L, Müller E, Hildebrandt C, Raschner C. Biological Maturity Status Strongly Intensifies the Relative Age Effect in Alpine Ski Racing. PLoS One 2016; 11:e0160969. [PMID: 27504832 PMCID: PMC4978382 DOI: 10.1371/journal.pone.0160969] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 07/27/2016] [Indexed: 11/18/2022] Open
Abstract
The relative age effect (RAE) is a well-documented phenomenon in youth sports. This effect exists when the relative age quarter distribution of selected athletes shows a biased distribution with an over-representation of relatively older athletes. In alpine ski racing, it exists in all age categories (national youth levels up to World Cup). Studies so far could demonstrate that selected ski racers are relatively older, taller and heavier. It could be hypothesized that relatively younger athletes nearly only have a chance for selection if they are early maturing. However, surprisingly this influence of the biological maturity status on the RAE could not be proven, yet. Therefore, the aim of the present study was to investigate the influence of the biological maturity status on the RAE in dependence of the level of competition. The study investigated 372 elite youth ski racers: 234 provincial ski racers (P-SR; high level of competition) and 137 national ski racers (N-SR; very high level of competition). Anthropometric characteristics were measured to calculate the age at peak height velocity (APHV) as an indicator of the biological maturity status. A significant RAE was present among both P-SR and N-SR, with a larger effect size among the latter group. The N-SR significantly differed in APHV from the P-SR. The distribution of normal, early and late maturing athletes significantly differed from the expected normal distribution among the N-SR, not among the P-SR. Hardly any late maturing N-SR were present; 41.7% of the male and 34% of the female N-SR of the last relative age quarter were early maturing. These findings clearly demonstrate the significant influence of the biological maturity status on the selection process of youth alpine ski racing in dependence of the level of competition. Relatively younger athletes seem to have a chance of selection only if they are early maturing.
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Affiliation(s)
- Lisa Müller
- Department of Sport Science, University of Innsbruck, Innsbruck, Tyrol, Austria
- * E-mail:
| | - Erich Müller
- Department of Sport Science and Kinesiology, University of Salzburg, Salzburg, Salzburg, Austria
| | - Carolin Hildebrandt
- Department of Sport Science, University of Innsbruck, Innsbruck, Tyrol, Austria
| | - Christian Raschner
- Department of Sport Science, University of Innsbruck, Innsbruck, Tyrol, Austria
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47
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Jordan MJ, Aagaard P, Herzog W. Rapid hamstrings/quadriceps strength in ACL-reconstructed elite Alpine ski racers. Med Sci Sports Exerc 2016; 47:109-19. [PMID: 24824771 DOI: 10.1249/mss.0000000000000375] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Because of the importance of hamstrings (HAM) and quadriceps (QUAD) strength for anterior cruciate ligament (ACL) injury prevention and the high incidence of ACL injury in ski racing, HAM and QUAD maximal and explosive strength were assessed in ski racers with and without ACL reconstruction (ACL-R). METHODS Uninjured (n = 13 males, n = 8 females) and ACL-R (n = 3 males, n = 5 females, 25.0 ± 11.3 months after operation) elite ski racers performed maximal voluntary isometric HAM and QUAD contractions to obtain maximal torque (MVC) and rate of torque development (RTD) at 0-50, 0-100, 0-150, and 0-200 ms. MVC and RTD (per kilogram body mass) were calculated for the uninjured group to compare between sexes and to compare the control group with the ACL-R limb and unaffected limb of the ACL-R skiers. HAM/QUAD MVC and RTD strength ratios (H/Q ratios) were also compared. RESULTS The ACL-R limb demonstrated significant HAM and QUAD deficits compared with the contralateral limb for MVC and late-phase RTD (P < 0.05). Uninjured male skiers also displayed a limb difference for HAM MVC and RTD at 150 ms (P < 0.05). QUAD MVC and RTD deficits were observed in the affected limb of ACL-R skiers, which led to an inflated H/Q ratio (50 ms) compared with that in uninjured controls (P < 0.05). Compared with male skiers, females displayed greater relative HAM RTD (50 ms) and an elevated H/Q RTD ratio (50 ms), suggesting enhanced ACL protection (P < 0.05). CONCLUSIONS Because of the strength demands of ski racing, our results suggest the importance of including HAM and QUAD strength assessments in the physical evaluation of uninjured skiers. Furthermore, HAM and QUAD strength should be assessed over a long-term period after surgery to identify chronic strength deficits in ACL-R ski racers.
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Affiliation(s)
- Matthew J Jordan
- 1Human Performance Laboratory, University of Calgary, Calgary, Alberta, CANADA; and 2Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster, University of Southern Denmark, Odense, DENMARK
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Patterson C, Raschner C, Platzer HP. The 2.5-minute loaded repeated jump test: evaluating anaerobic capacity in alpine ski racers with loaded countermovement jumps. J Strength Cond Res 2015; 28:2611-20. [PMID: 24584044 DOI: 10.1519/jsc.0000000000000436] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purposes of this study were to test the reproducibility of the 2.5-minute loaded repeated jump test (LRJT) and to test the effectiveness of general preparation period (GPP) training on anaerobic fitness of elite alpine ski racers with the LRJT. Thirteen male volunteers completed 2 LRJTs to examine reliability. Nine male Austrian elite junior racers were tested in June and October 2009. The LRJT consisted of 60 loaded countermovement jumps (LCMJs) with a loaded barbell equivalent to 40% bodyweight. Before the LRJT, the power (P) of a single LCMJ was determined. Power was calculated from ground reaction forces. The mean P was calculated for the complete test and for each 30-second interval. The interclass correlation coefficients (between 0.88 and 0.99) for main variables of the LRJT demonstrated a high reliability. A repeated-measures analysis of variance indicated that anaerobic capacity was significantly higher in October (p ≤ 0.05). The ski racers' single LCMJ P increased from 37.0 ± 1.2 W·kg to 39.0 ± 1.4 W·kg. The mean P of the total test improved from 33.6 ± 1.2 W·kg to 35.8 ± 1.3 W·kg, but relative effect of fatigue did not change. The GPP training improved the athletes' ability to produce and maintain muscular power. The LRJT is a reliable anaerobic test suitable for all alpine ski racing events because the 60 jumps simulate the approximate number of gates in slalom and giant slalom races and the 2.5 minutes is equivalent to the duration of the longest downhill race.
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Affiliation(s)
- Carson Patterson
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
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Müller L, Müller E, Hildebrandt C, Kornexl E, Raschner C. Influential Factors on the Relative Age Effect in Alpine Ski Racing. PLoS One 2015; 10:e0134744. [PMID: 26252793 PMCID: PMC4529241 DOI: 10.1371/journal.pone.0134744] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 07/13/2015] [Indexed: 01/01/2023] Open
Abstract
The relative age effect (RAE), which refers to an over-representation of selected athletes born early in the selection year, was proven to be present in alpine ski racing in all age categories at both national and international levels. However, the influential factors on, or the causal mechanisms of, the RAE are still unknown. Therefore, the aim of the present study was to examine three possible influential factors on the relative age effect in alpine skiing: physical performance, anthropometric characteristics and biological maturational status. The study included the investigation of 282 elite Austrian youth ski racers and 413 non-athletes (comparison group) of the same age (10–13 years) and region. Six physical performance tests were performed, body mass and height were assessed, and the age at peak height velocity (APHV) was calculated. A significant RAE was present in the ski racers. No differences were shown in the physical performance characteristics or in the calculated APHV between the relative age quarters. These results suggest that ski racers born in the last quarter can counteract the relative age disadvantages if they already present the same level of physical performance and maturational status as those born at the beginning of the year. The height and weight of ski racers born at the beginning of the year were significantly higher compared to the non-athletes, and ski racers born in relative age quarter 1 were taller and heavier compared to the ski racers of the other quarters. This indicates that the anthropometric characteristics influence the selection process in alpine ski racing, and that relatively older athletes are more likely to be selected if they exhibit advanced anthropometric characteristics.
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Affiliation(s)
- Lisa Müller
- Department of Sport Science, University of Innsbruck, Innsbruck, Tyrol, Austria
- * E-mail:
| | - Erich Müller
- Department of Sport Science and Kinesiology, University of Salzburg, Salzburg, Salzburg, Austria
| | - Carolin Hildebrandt
- Department of Sport Science, University of Innsbruck, Innsbruck, Tyrol, Austria
| | - Elmar Kornexl
- Department of Sport Science, University of Innsbruck, Innsbruck, Tyrol, Austria
| | - Christian Raschner
- Department of Sport Science, University of Innsbruck, Innsbruck, Tyrol, Austria
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Abstract
Alpine skiing is one of the most popular leisure time winter sporting activities. Skiing imposes high requirements concerning physical fitness, particularly regarding balance abilities. The main objective of this study was to evaluate the changes in balance performance of recreational skiers after a seven-day ski camp. A total of 78 students - 24 women and 54 men - participated in the study. The ski course was held in accordance with the official program of the Polish Ski Federation. The study sample was comprised of 43 beginners and 35 intermediate skiers. All students were tested with the MFT S3-Check, the day before and the day after the ski camp. The test system consisted of an unstable uniaxial platform, with an integrated sensor and corresponding software. Changes in balance performance (sensory and stability index) were evaluated using paired t-tests. Additionally, changes in sensory and stability categories, which were based on the norm data, were analyzed. Female and male participants showed significantly better sensory and stability indices after skiing. Considerable changes from weak or very weak to average or good balance categories could be seen after skiing for both sexes. Regarding skiing experience, both beginners and intermediate skiers improved their sensory and stability indices significantly after skiing. Hence, recreational alpine skiing resulted in better balance performance regardless of sex or skiing experience. Skiing as an outdoor activity offers the opportunity to improve balance performance with a positive impact on everyday life activities.
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