Alpine Skiing Research Articles

Side-to-side differences in knee laxity and side hop test may predispose an anterior cruciate ligament reinjury in competitive adolescent alpine skiers.

An anterior cruciate ligament (ACL) injury is a common, severe injury in alpine skiing, and anterior cruciate ligament reconstruction (ACLR) is frequently performed in competitive alpine skiers younger than 20 years old. To reduce the reinjury rate, both intrinsic and extrinsic risk factors should be examined. The aim of this study was to investigate possible intrinsic risk factors for an ACL reinjury in competitive alpine skiers. A cohort of 384 alpine skiers (191 males/193 females) from the Swedish ski high schools were prospectively followed during their high school years. The students were clinically examined and physically tested prior to each ski season. In addition, the RAND 36-Item health survey 1.0 (SF-36, Copyright 1994 Medical Outcome Trust, distributed by RAND Corporation) and injuries were prospectively registered. Thirty-one of the skiers (five males/26 females) had undergone an ACLR before entering the ski high school. This cohort was analyzed with respect to the occurrence of, and possible risk factors for an ACL reinjury (including ipsilateral and contralateral ACL injuries). Skiers who sustained an ACL reinjury were called the “ACL reinjury group,” and those who did not sustain an ACL reinjury were called the “ACL injury group.” Notably, 12 of the 31 students (39%), ten female and two male skiers, aged 16.5 (SD 0.5) years, sustained an ACL reinjury during the two first years at the ski high school. In addition, 10 of the 12 ACL reinjuries occurred within 10–23 months from the first injury [m 14.8 (SD4.7)] and two ACL reinjuries occurred at 29 and 47 months, respectively, from the first injury. It is noted that eight of the ACL reinjuries were to the ipsilateral knee and four to the contralateral knee. There were no differences between the groups with respect to muscle flexibility in the lower extremity, Beighton score, and one leg hop for distance or square hop test. Side-to-side differences were found with respect to knee joint laxity, >3 mm, measured with KT-1000 arthrometer (p = 0.02), and the side hop test (p = 0.04). RAND 36-Item health survey did not predict an ACL reinjury. In conclusion, a side-to-side difference in the side hop test and knee joint laxity (KT-1000) may predispose an ACL reinjury in competitive adolescent alpine skiers.

Knee injuries in winter sports

Winter sports represent arelevant entity for knee injuries due to their great popularity. In alpine skiing and snowboarding, knee joint injuries are the most common affected body regions, while in ice hockey they are in third place. Various accident mechanisms lead to different injury types and severities. In addition to medial collateral ligament injuries, anterior cruciate ligament injuries are of particular importance. In professional sports, severe combination injuries are more common. Therapy is exemplified using the anterior cruciate ligament rupture. The gold standard is replacement ligament surgery. The return-to-sport rate of 80% for skiing and snowboarding is comparable to summer sports such as football, basketball or baseball. For ice hockey, it is even better. Prevention is possible by targeted training programs, but also by optimizing the equipment and its adjustment.

Influence of Alpine Skiing on Health-Related Quality of Life and Physical Self-Concept in Physically Active Adults over 55 Years of Age.

Background: Older adults have the highest rates of a sedentary lifestyle. Alpine skiing could be considered a suitable activity to encourage continued sports practice and improve the health of this population in winter. The aim of this study was to analyse the relationship between the practice of alpine skiing and health-related quality of life (HRQoL), physical self-concept (PSC), and sport motivation. Methods: The study design was cross-sectional and descriptive, involving 280 Spanish adults aged over 55 years and physically active (75.35% skiers). To assess physical activity, PSC, HRQoL, and sport motivation, we used the Rapid Assessment of Physical Activity Questionnaire (RAPA-Q), the Physical Self-Perception Profile (PSPP 30), the Health-Related Quality of Life (SF-36), and the Sport Motivation Scale (SMS) questionnaires, respectively. Results: In the skier’s group, higher values were found for PSC (p < 0.001; d = 0.64), the physical component of HRQoL (p < 0.001, d = 0.48), physical function (p < 0.001, d = 61), and intrinsic motivation (p < 0.001; d = 0.85). The practice of alpine skiing was associated with higher levels of the physical health component (ORadj = 2.13, 95% CI 1.18–3.95, p = 0.013), PSC (ORadj = 2.92, 95% CI 1.58–5.52, p < 0.001), and intrinsic motivation (ORadj = 2.24, 95% CI 1.22–4.23, p = 0.010). Conclusions: The practice of alpine skiing is positively associated with higher values of HRQoL, PSC, and intrinsic motivation, and based on the above, it seems that alpine skiing can contribute to healthy ageing and improve the quality of life of older adults.

Fractures of tibial shaft and tibial head in winter sports

Injuries in alpine skiing often affect the lower extremities, in particular the knee joint and lower leg. In addition to conventional radiological diagnostics, CT and, in the case of fractures of the knee joint area, MRI also play an important role. In the case of tibial head fractures, especially if there has been adislocation mechanism, there is an increased risk of vascular and nerve injuries. Lower leg fractures are predestined for the development of acompartment syndrome. For these reasons, an exact survey of the vascular-nerve status and amonitoring of the soft tissues should be carried out. In the further therapy, whether conservative or surgical, the soft tissue situation must also be included in the planning. In the case of tibial head fractures in particular, the choice of the right approach is essential for agood result in surgical therapy. Angle-stable plate osteosynthesis and screw osteosynthesis play the most important role as osteosynthesis methods in the knee joint area. In the case of fractures in the shaft area, medullary nail osteosynthesis or angle-stable plate systems are primarily used. In the case of severely compromised soft tissue or unstable situations, it may be necessary to apply an external fixator first. The initiated therapy should enable functional follow-up treatment as early as possible. Good physical fitness, driving-specific training, but also good core stabilization have apreventative effect against injuries. In addition, the correct material coordination between ski boot, binding and ski is important for accident prevention.

Effects of physical stress in alpine skiing on psychological, physiological, and biomechanical parameters: An individual approach.

Alpine skiing is an attractive winter sport that often includes mental and physical demands. Since skiing is often done for several hours, fatigue processes occur that might lead to action errors associated with a higher risk of accidents and injuries. The aim of this study was to investigate the timing of changes in subjective, physiological, and biomechanical parameters during a physically demanding, standardized, non-competitive alpine skiing session. A group of 22 experienced male skiers carried out 10 runs, each lasting between 150 and 180 s, at a turn rate of 80 turns per minute with their best skiing technique. Immediately after the run, skiers reported ratings of fatigue, and other affective states. During skiing, breathing pattern and biomechanical data of the ski turns as radial force, turn duration, edge angle symmetry, and a composed motion quality score were recorded. Analyses of variances on skiers showing signs of fatigue (n =16) revealed that only the subjective data changed significantly over time: fatigue and worry increased, vitality and calm decreased. Subsequently, individual change points analyses were computed to localize abrupt distribution or statistical changes in time series data. For some skiers, abrupt changes at certain runs in physiological and/or biomechanical parameters were observed in addition to subjective data. The results show general effects in subjective data, and individual fatigue-related patterns concerning the onset of changes in subjective, physiological, and biomechanical parameters. Individuality of response to fatigue should be considered when studying indicators of fatigue data. Based on the general effects in subjective data, it is concluded that focusing on self-regulation and self-awareness may play a key role, as subjective variables have been shown generally sensitive to the physical stress in alpine skiing. In the future, customized algorithms that indicate the onset of fatigue could be developed to improve alpine skiers' self-awareness and self-regulation, potentially leading to fewer action errors.

Injuries of the foot and ankle in winter sports

Winter sports injuries of the foot and ankle are arelevant entity due to the high enthusiasm for alpine skiing and snowboarding. The condition of the footwear and rigidity of the binding have asignificant influence on the pathobiomechanics of fracture development and have been shown to influence the frequency of knee and ankle injuries. Foot injuries are rare due to the sport-specific footwear with good padding and frequent hard shell casings.

Classroom Teaching Design of Alpine Skiing Based on Virtual Reality Technology

Due to the limitation of venues for seasonal projects, it is a great challenge for students to adapt and maintain their sports status in non-snow seasons. Therefore, it is very important to do well in the non-snow season Lu-snow conversion training. At this stage, when the school formulates the teaching work plan for the school year, due to the limitation of the venue, the non-snow season Lu-snow conversion training is mainly based on physical training, while special skills training is supplemented, and there are problems such as poor teaching effect, insufficient teaching methods, and single practice means. At the same time, due to the reduction or even suspension of technical movement training in non-snow seasons, the teaching of alpine skiing lacks continuity and systematicity, which affects teaching effect. With the application of virtual reality technology in alpine skiing courses, this study conducts experimental research on the teaching and training effects in non-snow seasons, demonstrates the advantages of virtual reality technology in alpine skiing teaching and training, and optimizes the conversion of alpine skiing between land and snow in non-snow seasons.

Emergency Service Assistance for Injuries on Alpine Ski Slopes: A Cross-Sectional Study.

Injuries on alpine ski slopes have been described in cohorts of a reasonable sample size, but constant improvements in safety gear, increased use of airborne rescue, and safety measures during the coronavirus disease 2019 (COVID-19) pandemic mandate re-evaluation. Therefore, the purpose of this study was to evaluate skiing and snowboarding injuries, effectiveness of airborne rescue, and impact of the COVID-19 pandemic on a large sample size. Data on alpine injuries were prospectively collected from the state emergency services dispatch center in the state of Tyrol (Austria). A total of 10,143 patients were identified, with an average age of 33.5 years (SD = 20.36). The ski patrol was involved in 8,606 cases (84.9%) and some patients (n = 1,536; 15.1%) required helicopter rescue. A total of 10,143 patients were identified from the dataset of the emergency dispatch center. The most frequently injured region was the knee (30.2%), and it was followed by the shoulder (12.9%), the lower leg (9.5%), and the head/skull (9.5%). The present findings indicate that the most frequent site of injuries on alpine slopes is the knee, and life-threatening injuries are rare. Airborne rescue is very time-effective, however clinical studies with patient follow-up should be emphasized to determine the impact of airborne rescue on patient outcome. The present findings indicate that the duration of all rescue operations has been prolonged as a result of the introduction of safety measures during the COVID-19 pandemic.

Association of Gene Variants for Mechanical and Metabolic Muscle Quality with Cardiorespiratory and Muscular Variables Related to Performance in Skiing Athletes.

Background: Skiing is a popular outdoor sport posing different requirements on musculoskeletal and cardiorespiratory function to excel in competition. The extent to which genotypic features contribute to the development of performance with years of ski-specific training remains to be elucidated. We therefore tested whether prominent polymorphisms in genes for angiotensin converting enzyme (ACE-I/D, rs1799752), tenascin-C (TNC, rs2104772), actinin-3 (ACTN3, rs1815739) and PTK2 (rs7460 and rs7843014) are associated with the differentiation of cellular hallmarks of muscle metabolism and contraction in high level skiers. Material & Methods: Forty-three skiers of a world-leading national ski team performed exhaustive cardiopulmonary exercise testing as well as isokinetic strength testing for single contractions, whereby 230 cardiopulmonary measurements were performed in the period from 2015–2018. A total of 168 and 62 data measurements were from the Alpine and Nordic skiing squads, respectively. Ninety-five and one hundred thirty-five measurements, respectively, were from male and female athletes. The average (±SD) age was 21.5 ± 3.0 years, height 174.0 ± 8.7 cm, and weight 71.0 ± 10.9 kg for the analysed skiers. Furthermore, all skiers were analysed concerning their genotype ACE-I/D, Tenascin C, ACTN3, PTK2. Results: The genotype distribution deviated from Hardy–Weinberg equilibrium for the ACTN3 genotype, where rs1815739-TT genotypes (corresponding to the nonsense mutation) were overrepresented in world-class skiers, indicating a slow muscle fibre phenotype. Furthermore, the heterozygous rs2104772-AT genotypes of TNC also demonstrated the best scaled peak power output values during ramp exercise to exhaustion. The highest values under maximum performance for heart rate were associated with the rs1799752-II and rs1815739-CC genotypes. The lowest values for peak power of single contractions were achieved for rs1815739-CC, rs1799752-II and rs7843014-CT genotypes. The skiing discipline demonstrated a main influence on cardiorespiratory parameters but did not further interact with genotype-associated variability in performance. Discussion: Classically, it is pointed out that muscles of, for example, alpine skiers do not possess a distinct fibre type composition, but that skiers tend to have a preponderance of slow-twitch fibres. Consequently, our findings of an overrepresentation of ACTN3-TT genotypes in a highly selective sample of elite world class skiers support the potential superiority of a slow fibre type distribution. Conclusions: We suggest that one competitive advantage that results from a slow, typically fatigue-resistant fibre type distribution might be that performance during intense training days is better preserved, whereby simply a higher technical training volume can be performed, yielding to a competitive advantage.

Quantitative downhill skiing technique analysis according to ski instruction curricula: A proof-of-concept study applying principal component analysis on wearable sensor data.

Downhill skiing technique represents the complex coordinative movement patterns needed to control skiing motion. While scientific understanding of skiing technique is still incomplete, not least due to challenges in objectively measuring it, practitioners such as ski instructors have developed sophisticated and comprehensive descriptions of skiing technique. The current paper describes a 3-step proof-of-concept study introducing a technology platform for quantifying skiing technique that utilizes the practitioners’ expert knowledge. The approach utilizes an inertial measurement unit system (Xsens™) and presents a motion analysis algorithm based on the Principal Movement (PM) concept. In step 1, certified ski instructors skied specified technique elements according to technique variations described in ski instruction curricula. The obtained data was used to establish a PM-coordinate system for skiing movements. In step 2, the techniques parallel and carving turns were compared. Step 3 presents a case study where the technique analysis methodology is applied to advise an individual skier on potential technique improvements. All objectives of the study were met, proving the suitability of the proposed technology for scientific and applied technique evaluations of downhill skiing. The underlying conceptual approach - utilizing expert knowledge and skills to generate tailored variability in motion data (step 1) that then dominate the orientation of the PMs, which, in turn, can serve as measures for technique elements of interest - could be applied in many other sports or for other applications in human movement analyses.

Aerodynamic influence of an alpine skier’s arms

Understanding how postural changes in alpine skiing affect the overall aerodynamic drag is highly important for enhancing performance. Although the arm configuration of the athlete can have a significant impact on the overall drag force, this effect is currently less understood. The purpose of this investigation was to examine how the arms of an alpine skier influence the overall drag. Experiments were performed in a wind tunnel for a male and female athlete, and computational fluid dynamics simulations were performed on 3D scans of the athletes. The influence of the arm configurations in three different scenarios are considered; low-tucked, high-tucked, and flight postures. Consistent trends are found for both athletes and between the experiments and simulations. In general, the arms were found to be highly influential of the overall drag, and hence also performance in alpine skiing. For the low-tucked posture, the maximum variation in total drag area depending upon the angle of the underarms is 2.8%, with the lowest drag found with a medium angle of 20∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^\\circ $$\\end{document} to 25∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^\\circ $$\\end{document}. For the high-tuck posture, the difference in drag area between a closed and open posture was found to be 17% to 21%. The flight postures showed the highest influence of arm configurations, with a maximum difference in drag area of 64% between the considered postures. These results contribute to the understanding of aerodynamics in alpine skiing, and could be implemented directly in the training of athletes to improve their aerodynamic performance.

Knowledge graph of alpine skiing events: A focus on meteorological conditions.

Alpine skiing, as an outdoor winter sport, is particularly vulnerable to the variation of meteorological conditions. Scattered and multi-source big data cannot be fully utilized to conduct effective decision analyses by conventional data analysis methods. Presently, knowledge graphs are the most advanced organization form of knowledge base, which can make explicit the complex relationships among different objects. Thus, introducing knowledge graph to the event management of alpine skiing is significant to improve the ability of risk prediction and decision-making. In this research, we analyze the components and dynamic characteristics of alpine skiing, and construct an “Object-Characteristic-Relation” representation model to express multi-level knowledge. Moreover, we propose a “Characteristic-value- Relationship” representation method based on the multi-source data, to construct the knowledge graph of alpine skiing. With the proposed method, comprehensive relationships between meteorological conditions and alpine skiing can be represented clearly, and support further knowledge reasoning for the event management under meteorological conditions. We have tested the utility of the proposed method in a case study of 2018 Winter Olympics in PyeongChang. The case study realizes an semi-automatic construction of knowledge graph for alpine skiing, provides decision supports for event risk managements, according to different meteorological conditions, and grounds a foundation for future knowledge graph construction of other large-scale sport events.

Waxing activity as a potential source of exposure to per- and polyfluoroalkyl substances (PFAS) and other environmental contaminants among the US ski and snowboard community

BackgroundSkiers and snowboarders apply waxes and solvents to their equipment to enhance glide across the snow. Waxing results in exposures to per- and polyfluoroalkyl substances (PFAS) and particulate matter, which have been associated with adverse health effects among professional wax technicians in Scandinavia. However, little is known about exposure among people who participate at other levels of sport, including recreationally, in other regions. ObjectiveWe sought to characterize wax-related exposures among US skiers and snowboarders who participate across numerous levels of sport to expand scientific understanding of environmental health risks among this population. MethodsWe used an anonymous electronic survey to evaluate wax-related exposures among US cross-country and downhill skiers and snowboarders. Specifically, we assessed (1) duration of time involved with each sport in any role (2), intensity of wax-related exposures based on time spent in waxing areas, wax use, and wax type (3), frequency of fluorinated wax application, and (4) use of exposure interventions. ResultsParticipants tended to be long-term winter sports enthusiasts (e.g., median downhill skiing duration: 31 years). Nearly all (92%) participants personally applied some wax to their skis/snowboards and most applied waxes containing PFAS (67%) and solvents (62%). Ski professionals waxed the most pairs of skis with fluorinated waxes annually (median (IQR): 20 (1, 100)), though individuals participating recreationally also applied fluorinated waxes regularly. Exposure interventions were not widely used. SignificanceWaxing activities may pose significant risk of exposure to PFAS and other environmental contaminants among the US ski and snowboard community. Efforts are needed to reduce these exposures through changes to wax use patterns and broader adoption of exposure reduction strategies.

Nitrogen fertilizer enhances vegetation establishment of a high‐altitude machine‐graded ski slope

Machine grading is frequently required to prepare the terrain when building high‐altitude ski slopes in the Alps. However, this kind of disturbance alters the natural environment, destroying the vegetation and hampering its reestablishment. Thus, specific restoration plans are necessary to encourage the recovery of vegetation, which is already affected by different natural constraints in this harsh environment. One of the main critical factors affecting plant growth in high‐altitude areas is the lack of available nitrogen (N) in the soil. In this context, the addition of a slow‐release N fertilizer was carried out in an experimental revegetated ski slope between 2,800 and 2,900 m above sea level in the western Italian Alps. Both vegetation and soil were monitored during a 5‐year period in order to test the effectiveness of N addition on the restoration process. Even if effects on soil carbon and N contents were negligible, vegetation was remarkably affected by the fertilization, since the total vegetation cover and the species richness significantly increased. Against the expectations, there was a remarkable increase in spontaneous forbs, rather than in most of the sown graminoids, which slightly varied during the experimental period. Actually, graminoids responded in different ways, mostly increasing (likewise forbs), but the slight decrease of the dominant Festuca nigrescens (Chewing's Fescue) masked their spread. This study confirms the noteworthy role of N in high‐altitude alpine soils and consequently its importance to improve the restoration process of degraded ecosystems.

Biceps femoris long head morphology in youth competitive alpine skiers is associated with age, biological maturation and traumatic lower extremity injuries.

Lower extremity injuries are common in competitive alpine skiers, and the knee and lower leg are often affected. The hamstring muscles, especially the biceps femoris long head (BFlh), can stabilize the knee and the hip and may counteract various adverse loading patterns during typical mechanisms leading to severe lower extremity injuries. The aim of the present study was to describe BFlh morphology in youth competitive alpine skiers in relation to sex, age and biological maturation and to investigate its association with the occurrence of traumatic lower extremity injuries in the upcoming season. 95 youth skiers underwent anthropometric measurements, maturity offset estimations and ultrasound assessment, followed by 12-months prospective injury surveillance. Unpaired t tests showed that the two sexes did not differ in BFlh morphology, including fascicle length (Lf), pennation angle (PA), muscle thickness (MT) and average anatomical cross-sectional area (ACSAavg). In contrast, U16 skiers had longer fascicles than U15 skiers (9.5 ± 1.3 cm vs 8.9 ± 1.3 cm, p < 0.05). Linear regression analyses revealed that maturity offset was associated with Lf (R 2 = 0.129, p < 0.001), MT (R 2 = 0.244, p < 0.001) and ACSAavg (R 2 = 0.065, p = 0.007). No association was found between maturity offset and PA (p = 0.524). According to a binary logistic regression analysis, ACSAavg was significantly associated with the occurrence of traumatic lower extremity injuries (Chi-square = 4.627, p = 0.031, RNagelkerke 2 = 0.064, Cohen f = 0.07). The present study showed that BFlh morphology is age- and biological maturation-dependent and that BFlh ACSAavg can be considered a relevant modifiable variable associated with lower extremity injuries in youth competitive alpine skiers.

Is there a contextual interference effect for sub-elite alpine ski racers learning complex skills?

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.

Ski touring on groomed slopes: Analyzing opportunities, threats and areas of conflict associated with an emerging outdoor activity

Ski touring on groomed slopes (= slope ski touring) has experienced a boom in recent years. However, investigations in terms of slope ski touring and ski tourers are scarce. Thus, there has been a call for more research that also encompasses stakeholders’ opinions. This study aims to provide deeper insights into the trend of slope ski touring along with associated risks and opportunities as well as areas of conflict. Two qualitative studies were conducted: Study A covered interviews with 14 slope ski touring experts; study B surveyed 14 ropeway industry experts, who represented the main stakeholder groups. The results revealed that slope ski touring is an emerging trend (RQ1), since there is an increased number of ski tourers in ski resorts. The growing numbers of slope ski tourers are giving rise to economic, health and social opportunities. Both expert groups confirmed that this emerging trend is also associated with certain burden—relating to safety issues due to overcrowding on the one hand and to financial burdens for the ropeway infrastructure (RQ2) on the other. The studies also showed that there are areas of conflict, for example, due to a lack of ascent tracks, adverse behavior leading to rule violations and scarce parking. Furthermore, conflicts could be noted between different groups on the mountain (especially alpine skiers vs. slope ski tourers; slope ski tourers vs. mountain ropeway operators); eventually, ropeway operators have often been facing the financial burden of receiving no income from slope ski tourers. Solutions that could nip the burdens, risks and conflicts are still few and answers are missing (RQ3 and RQ4). For managers it is important to understand that ski touring on slopes is the European Alps an emerging trend with increasing economic, health and social relevance. The interests of users have changed over time. Areas of conflict are areas with a risk of collision with other athletes or ropeway operators. Ski touring on slopes offer new opportunities for smaller specialized ski resorts and their gastronomic services. Experts recommend separate ascent lanes for this activity, to enhance the safety. Financial contributions by this group of athletes are still an open question.

Energy Balance And Body Composition In Elite Alpine Skiers During Training At Altitude And Across The Competitive Season

Alpine skiing is characterized by phases of demanding on-snow glacier training and competitions in extreme environments, where maintaining body composition (BC) is crucial for performance and may play a role in injury prevention. However, sport-specific literature on energy balance (EB) and strategies to avoid unfavorable changes in BC are still lacking. PURPOSE: To analyze EB and BC during a training camp at altitude and over the course of a competitive season. METHODS: In a prospective observational study, active male (n = 9, 27 ± 2.9 yrs) and female (n = 10, 25 ± 3.0 yrs) international skiers, competing in either speed (SPEED; n = 10) or technical (TEC; n = 9) disciplines, completed a 7 to 15-day training camp at altitude (base: 1800 m, glacier: 3500 m). BC (displacement plethysmography and bioelectrical impedance) was assessed at baseline, directly before and after the camp and at the end of the season. At altitude, food intake was assessed directly and indirectly, urine samples were collected for estimation of energy expenditure (doubly labelled water isotope method). RESULTS: During the training camp, an overall increase in body mass (BM, p = 0.011) and fat mass (FM, p < 0.001) was observed, whereas FFM remained unchanged. Increases in FM were prominent in men (p < 0.001) and SPEED (p = 0.002), but not in women or TEC. An average total daily energy expenditure (TEE) of 4088 ± 895 kcal/d and an energy intake (EI) of 4375 ± 1223 kcal resulted in an overall positive EB. EE in SPEED was significantly higher than in TEC (p = 0.03), with the highest EE observed in male speed athletes (~5900 kcal). Moreover, EB differed (p = 0.01) between men (760 ± 890 kcal/d) and women (-138 ± 490 kcal/d). Over the course of a season, FFM (p = 0.007) and skeletal muscle mass (SMM, p = 0.05) decreased significantly. Whereas women tended lose more SMM than men (p = 0.09), reductions in BM tended to be greater in male when compared to female athletes (p = 0.07). CONCLUSION: The findings indicate that alpine skiers are able to meet the high energy demands during a short-term training camp, but not over the course of a competitive season. Therefore, BC should be monitored during key training and competition phases to identify athletes at risk and -if necessary- nutritional support should be provided to avoid being in a negative EB.

An Epidemiological Study On The Causes Of Injury And Recovery Time Of Athletes In National Winter Events

PURPOSE: This study conducted an epidemiological investigation on the cause and recovery time of sports injuries during the the preparation phase of winter events and revealed the regular occurrence of sports injuries in winter events. METHODS: The main research methods of this study are related to epidemiology, including the record sheets of sports injuries of the 10 national winter sports teams and the record statistics of the daily injuries of the team doctors. RESULTS: According to the different causes of injury, we divide the causes of injury into strain, accident, technical instability, fatigue, learning new techniques, insufficient preparation activities, fields and facilities, interference by others, and equipment failure. The primary cause of injury is a strain (37.91%), including acute onset of chronic injury and the gradual deterioration of chronic injury. The second cause of injury was accidents (25.63%), mainly due to general falls during training. The third reason for the damage is technical instability (17.69%), mainly due to damage caused by learning new technology or technological transformation. The fourth cause of injury is fatigue (10.11%), which is a mainly acute injury under fatigue. Others included learning new moves (4.33%), insufficient preparation activities (2.17%), fields and facilities (1.26%), interference (0.54%), and equipment failure (0.18%). The percentage of injured athletes who resume training within 7 days is 88.86%, and the percentage of recovery training within 30 days is 98.65%. Among them, alpine skiing, freestyle skiing aerials, and freestyle skiing obstacle chasing events accounted for less than 70% of recovery training within 7 days. CONCLUSIONS: The winter event injury mainly comes from the acute onset of chronic injury and the gradual deterioration of chronic injury. As some athletes are transferred from other events to winter events, there are more acute injuries caused by learning or modification techniques. Most of the injuries caused by the event can resume training within a week.

Investigation And Analysis Of Injuries And Diseases Of National Teams Of Winter Events In 2018-2019 Season

PURPOSE: By summarizing and analyzing the occurrence and injuries of athletes in the national training team of the 2018-2019 winter season, to understand the main injury problems of athletes, and to provide a scientific reference for athletes' injury prevention and disease prevention. METHODS: By recording 928 injuries of winter sports (including figure skating, aerials, snowmobile sled, snowboarding, ski jumping, ski jumping, biathlon, alpine skiing, cross-country skiing, and ice hockey) in training and competitions in the 2018-2019 season, organizing, summarizing and analyzing the epidemiological results of winter events. RESULTS: 1) Gender distribution: In this season, male injuries accounted for 50.9%, and females accounted for 49.1%. Male and female athletes had similar injuries. 2) Injury parts: The vulnerable parts are the knee (25.09%), waist (15.51%), ankle (9.39%), and thigh (8.84%). Among them, the knee joint injuries are mostly knee patellar tendinitis, pes anserinus tendinitis, knee fat pad inflammation, and sprains. Lumbar injuries are mostly muscle strain, and lumbar disc herniation; ankle joint injuries are mostly sprained; thigh injuries are mostly thigh muscle strain. 3) Injury types: The most common types of injuries are muscles (40.58%), ligaments (18.3%), and tendons (13.4%). Muscle and tendon injuries are mostly concentrated around the knee joint and waist; ligament injuries are more common at the ankle and wrist joints. CONCLUSIONS: The injury probability of male and female athletes in the winter event is the same. The lower limbs are mostly in common, and muscles, tendons, and ligaments have been easily injured. Analyzing injury mechanisms in high-risk Olympic winter sports are essential to better direct injury-prevention strategies.