Mittuniversitetets forskningsavdelning Sports Tech Research Centre (STRC) driver sedan en tid tillbaka ett projekt i samarbete med Svenska Skidförbundet. Syftet med projektet är att bidra till det alpina landslagets framgång genom att utveckla fartdräkterna som åkarna använder, främst genom att minska fartdräktens påverkan av luftmotståndet. En del av projektet innefattar vindtunneltester av dessa fartdräkter för att mäta dess luftmotstånd. Syftet med detta examensarbete är att bidra till fortsatt utveckling genom att underlätta dessa tester. Syftet är även att undersöka och utvärdera en ny tillverkningsmetod för att designa och tillverka testdockor avsedda att använda i vindtunneltester. Målet var att designa och tillverka en testdocka utifrån en alpinskidåkare på elitnivå. Dockan skulle kunna kläs i en fartdräkt och användas i en vindtunnel, och där visa likvärdiga mätvärden för luftmotståndet som för testpersonen och en lägre standardavvikelse. Arbetet började med att skanna testpersonen som testdockan skulle skapas utifrån. Fotogrammetri användes som skanningsmetod. Därefter följde 3D-modellering och beredning inför tillverkningen. Testdockan tillverkades av horisontella spånskivelager sammanfogade med varandra. Jämförande vindtunneltester utfördes sedan på testdockan och testpersonen den är skapad utefter, i syfte att validera dockan och uppnå liknande mätvärden. Den resulterande 3D-modellen från skanning och 3D-modellering kunde valideras mot testpersonens verkliga mått och var därför användbar för att tillverka den fysiska testdockan. Resultatet efter montering och ytbehandling var en fysisk testdocka som kunde kläs med fartdräkt och tillhörande utrustning. Dockans dimensioner stämde överens tillräckligt bra med testpersonens dimensioner. Vindtunneltesterna visade på ett luftmotstånd på ca 19,8N för testpersonen och ca 28,1N för testdockan. Detta beror troligtvis på skillnader mellan deras positionering. Standardavvikelsen av luftmotståndet för testpersonen och testdockan var ca 3,76N respektive ca 4,33N. Fotogrammetri följt av 3D-modellering i Rhino lämpade sig för denna typ av modell med organiska former. Tillverkningsmetoden krävde mycket efterarbete men gav ett bra resultat i just detta arbete, där de minsta detaljerna som t. ex ansikte och händer inte var av största vikt. Målet att tillverka en testdocka med fungerande funktioner uppfylldes. Ökningen av standardavvikelsen för testdockans luftmotstånd gör att den delen av målet inte uppfylldes, men ytterligare undersökningar behöver utföras innan slutsatser kan dras om dockans användbarhet. / Mid Sweden University's research department Sports Tech Research Center has been running a project in collaboration with the Swedish Ski Association for some time. The purpose of the project is to contribute to the success of the Swedish alpine national team by developing the race suits that the riders use, mainly by reducing the race suit's impact on air resistance. Part of the project includes wind tunnel tests of these race suits to measure its air resistance. The purpose of this thesis is to contribute to further development by facilitating these tests. The purpose is also to investigate and evaluate a new manufacturing method for designing and manufacturing test dummies intended for use in wind tunnel tests. The goal was to design and manufacture a test dummy based on an alpine skier at an elite level. The dummy was to be dressed in a race suit and used in a wind tunnel, and there show equivalent measured values for the air resistance of the test person and a lower standard deviation. The work began with scanning the test person from whom the test dummy was to be created. Photogrammetry was used as the scanning method. This was followed by 3D modulation and preparation for production. The test dummy was made of horizontal chipboard layers joined together. Comparative wind tunnel tests were then performed on the test dummy and the test person it is created from, in order to validate the dummy and achieve similar measurement values. The resulting 3D model from scanning and 3D modulation could be validated against the test person's actual measurements and was therefore useful for manufacturing the physical test dummy. The result after assembly and surface treatment was a physical test dummy that could be dressed in a speed suit and associated equipment. The dimensions of the dummy matched well enough with the dimensions of the test person. The wind tunnel tests showed an air resistance of about 19.8N for the test person and about 28.1N for the test dummy. This is probably due to differences between their positioning. The standard deviation of the air resistance for the test person and the test dummy was about 3.76N and about 4.33N, respectively. Photogrammetry followed by 3D modulation in Rhino was suitable for this type of model with organic shapes. The manufacturing method required a lot of finishing work but gave a good result in this particular work, where the smallest details such as the face and hands were not of the utmost importance. The goal of manufacturing a test dummy with needed functions was met. The increase in the standard deviation of the test dummy's air resistance means that part of the goal was not met, but further investigations need to be carried out before conclusions can be drawn about the dummy´s usefulness / <p>2022-07-01</p>

Cross-country skiing has turned into the most highly competitive winter sport, with skiers having the ability to win by merely milliseconds. Every year researchers, ski - technicians, and athletes come together to prepare the ski base surface that gives the best possible results. However, much current information is based on the ski technician’s experience. Therefore, this project has been carried out to help to bridge the gap between ski technician’s knowledge and experimental research. The ski bases are passed through several surface preparation steps before competitions. Stone grinding and hand texturing are two of them. Since grinding cannot be specifically applied as per the environmental conditions, it is followed by texturing. This application of grinding and texturing changes the surface topography of the ski base, which will affect the contact area between the ski base surface and snow/ice and the wettability of the ski base. For this project, work is focused on how the application of different grinds and hand textures affects the wettability of the ski base. This project illustrates the change in wettability of ultra-high molecular weight polyethylene (UHMWPE) and its composites under the application of ten different commercial grinds followed by three other hands texturing. Surface topography was observed under an Optical profilometer, and wettability was measured by measuring the contact angles of droplets on these ski base materials. It was found that the hydrophobicity of ski base materials can be increased to a certain level by increasing the Arithmetic mean roughness (Ra) of specimens. Different ski base materials showed different hydrophobic behaviour when roughness was increased. Applying hand textured to different ground specimens again improved the hydrophobic behaviour of the ski base.

Poly- och perfluorerade ämnen, även kallad PFAS, har både globalt och i Sverige upptäckts i höga halter i mark samt i yt-och grundvatten de senaste åren. Kemikalierna är svårnedbrytbara och studier visar på att de bland annat är reproduktionsstörande hos djur. Källorna till utsläpp av PFAS är många, men något som uppmärksammats den senaste tiden är fluorvallor som används inom längdskidåkning. I den här studien undersöks hur användningen av skidvalla innehållande PFAS påverkar ett område samt hur dessa ämnen sprids. För att undersöka detta har tidigare mätningar utförda i anslutning till längdskidspår använts, för att se hur spridningen skett vid dem samt vilka koncentrationer som kan påträffas.  Mätningarna var utförda vid skidspår i Oslo, Trondheim, vid Vasaloppet samt vid en tävling i Maine, USA. För att visualisera var i Sverige påverkade områden skulle kunna finnas gjordes dessutom en karta där orter togs ut på två olika sätt. Skidvalla bidrar till att orsaka högre lokala koncentrationer av PFAS, och kan få en stor påverkan i de områden där mycket skidåkning pågår. Samtidigt är det svårt att dra tydliga slutsatser då det finns fåtal studier och många diffusa källor som kan bidra till spridningen av PFAS. / Per- and polyfluoroalkyl substances (PFAS) are man-made chemicals used for their water, grease, and dirt repellent properties. Today these substances are widespread due to their ability to spread through both air and water. PFAS are long-term persistent and have hazardous environmental impact. Among others, affecting the reproduction of animals and has been shown to accumulate in the food chain. One product containing PFAS that has recently gained attention is fluorinated ski wax, due to the ban imposed on fluorinated ski wax by the International Ski Federation (FIS) from the season 2021/2022.  To investigate how the use of ski wax containing PFAS spreads and affects the environment at areas with cross-country skiing, results from previous studies have been analyzed. The previous studies were located at cross-country ski areas in Oslo and Trondheim in Norway, Maine in the USA and at the location of the Swedish competition Vasaloppet. A map has also been made to visualize where in Sweden there might be areas who have been contaminated with per- and polyfluoroalkyl substances by the use of ski wax. To find the locations for these areas two different methods have been used.  The results of the previous studies shows that the use of fluorinated ski waxes gives higher local concentrations of PFAS at the locations of cross-country ski areas that are frequently used. However, it is still difficult to draw clear conclusions about how big the spread of PFAS contamination is, since the substances can be found in many different products and are easily spread. In the future there is a need for more studies and investigation to reach clearer conclusions. In addition, there is a need for more tests around different ski areas to see the impact that competitions have, but also how everyday skiing affects the spread of PFAS.

Syfte Undersöka biomekaniska och fysiologiska skillnader mellan modern och gammeldags stakteknik vid konstant submaximalt arbete på rullskidor. Metod Tolv manliga elitskidåkare rekryterades till studien (ålder: 21 ± 4 år, längd: 183,6 ± 9,3 cm, och vikt: 77,8 ± 10,3 kg). Efter en standardiserad uppvärmning genomfördes två deltester, om fyra minuter vardera, i modern och gammeldags stakning med en individanpassad hastighet och lutningen 2,5°. Syreförbrukningen och ventilation analyserades under testen och efter varje deltest togs ett laktatprov och skattning av ansträngning utifrån Borgs RPE. Testerna filmades, där vinklar sedan plockades ut i ett videoanalysprogram. De olika testvärdena analyserade sedan med Paired samples t-test samt Paired samples Wilcoxon signed-ranked test. Resultat Ingen signifikant skillnad påvisades mellan modern och gammeldags stakning för syreförbrukning, energiförbrukning, rörelseekonomi, andningsfrekvens samt laktathalt. Signifikanta skillnader påvisades för hjärtfrekvens, ventilation, respiratory exchange ratio (RER) samt Borg RPE, där gammeldags stakning uppvisade högre värden för samtliga variabler förutom RER. Även i en del ledvinklar samt för tiden i den kraftskapande- och återhämtningsfasen stakcyklerna och tyngdpunktsförflyttningen. Slutsatser Studien visar inga signifikanta skillnader i energikostnad, syrekonsumtion, rörelseekonomi samt blodlaktatskoncentration mellan modern och gammeldags stakning vid submaximalt arbete. Däremot finns signifikanta skillnader i hjärtfrekvens, ventilation samt den skattade tröttheten som tyder på att gammeldags stakning upplevs något mer ansträngande. Framtida forskning behövsför att avgöra om detta skiljer sig i annan lutning och hastighet. / Purpose Examine whether biomechanical and physiological variables differ between modern and old-fashioned double poling technique (OFDP) at a constant submaximal work rate during roller skiing. Methods Twelve male elite cross-country skiers were recruited (age: 21 ± 4 years, length: 183,6 ± 9,3 cm, and weight: 77,8 ± 10,3 kg). After a standardized two subtests followed, in modern and OFDP technique at an individual velocity and the incline 2,5°. Oxygen consumption and ventilation were measured during the testand lactate concentration as well as estimation of Borg RPE were measuredafter every subtest. The test was recorded and angles were analysed. Test values were analysed using Paired samples t-test as well as Paired samples Wilcoxon signed-ranked test. Results No significant difference in energy expenditure (EE), O2 consumption, gross efficiency (GE), breathing frequency (BF) and lactate were shown. Significant differences were shown between heart rate (HR), ventilation, RER and Borg RPE, where higher values were shown for OFDP at all variables except RER. Significant differences were shown in some joint angles as well as the time of the power creating phase,returning phase of the pole stroke and the centre of mass (COM) displacement. Conclusions No significant difference in EE, O2 consumption, GE and lactate between modern and OFDP during a submaximal work rate. Differences in HR and estimated exhaustion gives a hint of the OFDP being more exhausting. Future research is required to determine if this differs in other inclines and velocities.

Cross-country (c.c.) skiing is a complex sport discipline from both physiological and biomechanical perspectives, with varying course topographies that require different proportions of the involved sub-techniques to be utilised. A relatively new event in c.c. skiing is the sprint race, involving four separate heats, each lasting 2-4 min, with diverse demands from distance races associated with longer durations. Therefore, the overall aim of the current thesis has been to examine the biomechanical and physiological factors associated with sprint c.c. skiing performance through novel measurements conducted both in the field (Studies I-III) and the laboratory (Studies IV and V). In Study I sprint skiing velocities and sub-techniques were analysed with a differential global navigation satellite system in combination with video recording. In Studies II and III the effects of an increasing velocity (moderate, high and maximal) on the biomechanics of uphill classical skiing with the diagonal stride (DS) (Study II) and herringbone (HB) (Study III) sub-techniques were examined. In Study I the skiers completed the 1,425 m (2 x 712 m) sprint time trial (STT) in 207 s, at an average velocity of 24.8 km/h, with multiple technique transitions (range: 21-34) between skiing techniques (i.e., the different gears [G2-7]). A pacing strategy involving a fast start followed by a gradual slowing down (i.e., positive pacing) was employed as indicated by the 2.9% faster first than second lap. The slower second lap was primarily related to a slower (12.9%) uphill velocity with a shift from G3 towards a greater use of G2. The maximal oxygen uptake ( O2max) was related to the ability to maintain uphill skiing velocity and the fastest skiers used G3 to a greater extent than G2. In addition, maximal speed over short distances (50 and 20 m) with the G3 and double poling (DP) sub-techniques exerted an important impact on STT performance. Study II demonstrated that during uphill skiing (7.5°) with DS, skiers increased cycle rate and cycle length from moderate to high velocity, while cycle rate increased and cycle length decreased at maximal velocity. Absolute poling, gliding and kick times became gradually shorter with an elevated velocity. The rate of pole and leg force development increased with elevated velocity and the development of leg force in the normal direction was substantially faster during skiing on snow than previous findings for roller skiing, although the peak force was similar in both cases. The fastest skiers applied greater peak leg forces over shorter durations. Study III revealed that when employing the HB technique on a steep uphill slope (15°), the skiers positioned their skis laterally (“V” between 25 to 30°) and planted their poles at a slight lateral angle (8 to 12°), with most of the propulsive force being exerted on the inside forefoot. Of the total propulsive force, 77% was generated by the legs. The cycle rate increased across all three velocities (from 1.20 to 1.60 Hz), while cycle length only increased from moderate to high velocity (from 2.0 to 2.3 m). Finally, the magnitude and rate of leg force generation are important determinants of both DS and HB skiing performance, although the rate is more important in connection with DS, since this sub-technique involves gliding. In Studies IV and V skiers performed pre-tests for determination of gross efficiency (GE), O2max, and Vmax on a treadmill. The main performance test involved four self-paced STTs on a treadmill over a 1,300-m simulated course including three flat (1°) DP sections interspersed with two uphill (7°) DS sections. The modified GE method for estimating anaerobic energy production during skiing on varying terrain employed in Study IV revealed that the relative aerobic and anaerobic energy contributions were 82% and 18%, respectively, during the 232 s of skiing, with an accumulated oxygen (O2) deficit of 45 mL/kg. The STT performance time was largely explained by the GE (53%), followed by O2 (30%) and O2 deficit (15%). Therefore, training strategies designed to reduce energetic cost and improve GE should be examined in greater detail. In Study V metabolic responses and pacing strategies during the four successive STTs were investigated. The first and the last trials were the fastest (both 228 s) and were associated with both a substantially larger and a more rapid anaerobic energy supply, while the average O2 during all four STTs was similar. The individual variation in STT performance was explained primarily (69%) by the variation in O2 deficit. Furthermore, positive pacing was employed throughout all the STTs, but the pacing strategy became more even after the first trial. In addition, considerably higher (~ 30%) metabolic rates were generated on the uphill than on the flat sections of the course, reflecting an irregular production of anaerobic energy. Altogether, a fast start appears important for STT performance and high work rates during uphill skiing may exert a more pronounced impact on skiing performance outdoors, due to the reduction in velocity fluctuations and thereby overall air-drag. / <p>Vid tidpunkten för disputationen var följande delarbeten opublicerade: delarbete 5 inskickat</p><p>At the time of the doctoral defence the following papers were unpublished: paper 5 submitted</p>

The organisation of elite sport systems has been the focus of a great variety of different investigations over the past ten years. In particular, many studies have compared the structure and organisation of different national elite sport systems on the macro and meso levels. A result of the existing investigations is a clear convergence of the service portfolio different elite sport systems offer their athletes and coaches. Despite this current trend to a homogeneous elite sport system design, medal tables of major sport events suggest that some nations are still more successful than others in specific sports. This suggests that more successful sport systems might have found better ways to implement the otherwise similar and conventional support portfolio. However, there is a lack of studies that focus on what practices successful elite sport systems apply in the actual delivery of the support services to their athletes and coaches; in how far these practices are related to the ,success of the sport systems; if these practices look similar across different successful sport systems; and if these practices provide useful lessons for other systems to learn from. The management tool benchmarking appears to be a useful framework to guide such comparisons at the operational level. Thus, this thesis evaluated the applicability of this management concept for furthering understanding of elite sport system management. In order to conduct this evaluation it was decided to analyse the operational processes and structures two successful elite sport systems apply for the delivery of five elements of the elite sport support portfolio. In specific, the investigation focused on the comparison of the design of the squad system, the hierarchy of coaches within the squad system, the organisation of the coach education, as well as the provision of sport science and lifestyle support, which were the Benchmarking Objects of this study. The Swedish athletics and the Norwegian cross-country skiing national team, and the general elite sport support institutions they cooperate with, were chosen as the Benchmarking Subjects, i.e. the comparison partners, for this investigation. This research was based on a series of semi-structured interviews which were conducted with about 50 key pOSition holders such as coaches, athletes, lifestyle support managers, or performance diagnosticians during two study visits to Norway and Sweden. This study concluded that benchmarking can lead to insights into the operational management of successful elite sport systems. It must however also be stressed that benchmarking is not a universal remedy for the problems managers of elite sport systems face today. As this research showed, the two Benchmarking Subjects applied unexpected solutions for the delivery of some of the chosen Benchmarking Objects - and some of these practices appeared to be heavily linked to the organisational and cultural context of the investigated sport systems. Thus, it must be carefully evaluated for each process or structure, which is identified during a bench marking exercise, if it constitutes a transferable best practice which is applicable outside the organisational context of the respective Benchmarking Subject.

Diploma thesis aims to explore the representation of compensation methods and tools in ATC with representatives of Slovakia in cross - country skiing. Then obtain data on the state of theirs motor system especially the shortened muscle groups. After processing this data to compare them and create a design of supplement the compensation an individual plan. Key words: body burden, compensation, annual training cycle,locomotor system, shortened muscle groups, cross country skiing

Title: Biathletes long term physical preparedness level in preparatory period Objectives: To compare in selected control tests from prepartory period the best results of present biathlon junior representants and junior results of the best present biathlon sportsmen, who are nowadays in the world biathletes top, and to give long term development overview according to these tests. Methods: In this thesis, data collection method, data analysis method and comparison method was used. Data collection method was the first step where we summarized all available junior results from selected preparatory period tests. Furhter, the data analysis method was used to select the best achieved time for each junior competitor in selected tests and from all results. Comparison method was chosen for thesis conclusion where we compare and present all junior competitors best results in well-arranged tables and charts. Arithmetic mean was used as statistical method for work with results Results: On the grounds of performance level comparison shown in preparatory period control tests in 2001-2012 period, of present junior group and junior level performance of present top world biathlon sportsmen, we discovered that long term performance level of present juniors is worse than performance level of the then juniors....

This thesis suggests a method of how teaching pre-school children to ski. Project "how to teach children skiing with fun" was developed and based on age group characteristics and needs of the child. It also underlines that it is not important to teach the child skiing in a short period of time but to make a firm foundation for all kinds of physical movements that will be needed later for skiing and to create a positive attitude to skiing which in this age group works the best by playing games and having fun. This hypothesis was confirmed by results I gained during verifying my method in practise. Based on the test we can state that this method works very well in practise and the children engoyed it while having lots of fun. Generally,the purpose of this work was fulfilled and the obtained results should be a big asset in a theory of skiing and also in practise.

Title: Occurrence and Prevention of Asthma in Youth Division Cross-country Skiers Objectives: The aim of this thesis is to determine the incidence of asthma in youth division cross-country skiers and its prevention. Methods: This thesis will comprise the method of survey and content analysis of documents. Hypotheses: No.1 Assume that asthma will have lower prevalence in youth division cross- country skiers than in adult cross-country skiers. No.2 Assume that the majority of the surveyed cross-country skiing coaches met with asthmatic symptoms in their athletes. Results: We found that 12% of youth division athletes suffer from asthma and 24% from allergies. Keywords: cross country skiing, respiratory diseases, bronchial asthma, exercise-induced asthma, allergy prevention.