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The purpose of this study was to investigate the effects of acute moderate hypoxia (14.5% inspired oxygen fraction) on the magnitude of fatigue development during the different phases (work, recovery, and both) of a repeated-sprint test (10 x 6-s sprints interspersed with 30-s recovery) in healthy, trained males. This study also sought to investigate the relationship between anaerobic power reserve and fatigue during the aforementioned repeated-sprint test. Fourteen exercise-trained males completed four trials of the repeated-sprint test under each of the following conditions: (a) normoxia (20.93% inspired oxygen fraction), (b) acute hypoxia during the work intervals only, (c) acute hypoxia during the recovery intervals only, and (d) acute hypoxia during both the work and recovery intervals. The order of the experimental conditions was systematically balanced. Fatigue scores were not different between experimental conditions, despite the fact that arterial oxygen saturation values from the acute hypoxia during recovery condition and the acute hypoxia during both work and recovery condition differed significantly from the normoxia and acute hypoxia during work intervals only conditions (p < .001). There was no relationship between anaerobic power reserve and fatigue in any experimental condition. The results of the present study indicate that although the participants experienced different levels of hypoxia during the experimental trials, the degree of hypoxia was insufficient to alter mechanical performance during a repeated-sprint test. The lack of an effect on mechanical performance does not appear to be influenced by an individual's anaerobic power reserve. It may be inferred that the degree of hypoxia employed was neither severe enough as to impair levels of muscle oxygenation beyond what was experienced in normoxia, nor as to induce further fatigue related to central mechanisms. / Kinesiology

Previous research has identified strength as a key factor for performance in cross-country skiing. The purpose of the present study was to investigate the relationship between upper body strength and performance in swedish junior cross-country skiers. 33 swedish young men and 23 young women age 17,3 ± 1,0 years volunteered to participate in specific tests during a summer training camp were they completed a test battery consisting of bench press and bench pull. The strength variables obtained were correlated with FIS-points (International Ski Federation´s ranking points for distance and sprint performance) used as the performance indicator. Correlations were performed by Spearman´s rank correlation coefficient for all variables. The results showed that FIS-points for sprint correlated significantly with both bench press and bench pull. No significant correlation was found between FIS-points for distance and bench pull. These results may predict performance for cross-country skiers and indicate a justification for increased proportion of strength training.

Sammanfattning Syfte och frågeställningar Syftet är att undersöka om det föreligger något samband mellan 1RM i benböj och sprintlöpning på is kontra sambandet mellan sprintlöpning på barmark och 1RM i benböj för svenska damhockeyspelare i högsta serien SDHL. Finns det något samband mellan maxstyrka i 1RM i benböj och sprinter på barmark (utanför isen) hos svenska damhockeyspelare? Finns det något samband mellan maxstyrka i 1RM benböj och sprinter på is hos svenska damhockeyspelare? Finns det något samband mellan sprintlöpning på barmark och skridskosprinter på is? Metod Testerna utfördes vi två tillfällen med en veckas mellanrum. Vid första tillfället utfördes testerna i benböj ned till ett djup där lårbenet var parallellt med underlaget. Startvikten var 70% av den förväntade maxvikten och testpersonen hade två försök på varje vikt. Vid andra tillfället utfördes 30 meter sprint på barmark och på is och där fotoceller användes för mätning av tid (Time-it - basic set, ELEIKO). Fotocellsparen placerades på ställningar med en höjd på 91cm från underlaget med 1,5 meter avstånd från varandra och testpersonerna startade 0,5 meter innan första fotocellerna och fick välja själva när de skulle starta. Testpersonerna utförde två sprinter vardera på barmark respektive is där det bästa resultatet sedan användes i analysen. Samtliga analyser genomfördes i programmet SPSS. Resultat Studien resulterade i medelhöga negativa korrelationskoefficienter erhölls mellan variablerna 1RM i benböj och 30 meter barmarkssprint (r= -0,548). Ett svagt positivt samband hittades mellan variablerna 1RM och sprint på is (r = 0,164). Det fanns signifikanta skillnader mellan de två variablerna och med 95 procent säkerhet skiljer sig minst ett av medelvärdena ifrån de andra på ett sätt som inte beror på slumpen. På T-testet var Sig.värdet 0,000 på samtliga parametrar samt differensen i medelvärdet översteg 0,050 vilket gör att det inte går att dra någon slutsats över en större population. Slutsats Med vår studie kunde vi se ett starkare samband mellan testpersonernas prestation i sprinten på barmark och ett maximalt lyft i benböj (r = -0,548) än vad vi kunde se mellan resultaten i sprint på is och benböjen (r = 0,164) / <p>Ämneslärarprogrammet, Specialidrott</p>

A traditional warm-up (WU) for track sprinters usually includes a general WU, a series of mobility drills and some short sprint strides lasting 30-60 min in total. A WU of this duration might cause significant fatigue and impair sprint performance. Aim: To test the hypothesis that a traditional high intense warm-up of long duration would elicit fatigue and impair sprint performance. Methods: Five highly trained males competitive in endurance sports performed three different WU protocols on separate days in their postseason period. Their mean ± SD age, body mass and height were 24.2 ± 1.6 years, 78.4 ± 7.8 kg, 179.6 ± 8.8 cm. The study participants performed a timed 60 meter sprint on an indoor track. The traditional warm-up (LONG), started with 10 min of easy running; then 7 min of mobility drills followed by five sprints performed with 3-min break in between. The total duration of LONG was 35 minutes. The experimental warm-up (SHORT) was shorter and less intense; 10 min of easy running was followed by just one sprint. Both warm-up protocols were followed by 10 min of recovery, where participants were not allowed to sit down. A third test occasion served as control (CON), where participants did not conduct physical activity prior to the time trial, only 10 min of recovery. Participants also rated the satisfaction of their performance on a 10 point scale. Results: The results of 60 m time trial performance showed no significant differences among the different WU protocols (P = 0.20). The 60 m performance was better for SHORT (8.02 ± 0.10 sec) than for LONG (8.08 ± 0.16 sec) and CON (8.20 ± 0.21 sec). 4 of 5 participants experienced their fastest time trial following SHORT. It appeared that participants were significantly faster following SHORT (7.99 ± 0.22 ms-1) compared to LONG (7.77 ± 0.33 ms-1) in the final 10 m of the time trial (P = 0.05). The satisfaction after SHORT scored highest (6.9), followed by LONG (5.9) and CON (4.5). Conclusions: There is no significant difference between a traditional WU compared to a WU of shorter duration and lower intensity. The traditional WU showed a significant decline in running speed in the final stage of the time trial, which might be caused by fatigue.

Introduction Women’s soccer players need to train comprehensively to cope with the demands that exist during a soccer game. There are several studies on the relationship between muscle strength and jump and sprint ability. However, most studies are performed on male athletes.  Aim The aim of this study was to investigate the relationships between muscle strength and jump and sprint ability among elite female soccer players.  Method Nine female soccer players from a Swedish elite level team were included in the study. A quantitative approach in the form of a cross-sectional study was used. The participants performed a vertical jump, a drop jump, a 55-m sprint and a three-repetition maximum (3 RM) barbell squat test. Data collection took place at two different occasions, one at a track and field training facility for jumping and sprint tests, and one in the gym of the team facility for the squat test.  Results Significant correlations were observed between muscle strength and top running speed (r=0.77, p=0.15), 10-m (r=-0.66, p=0.05), 20-m (r=-0.73, p=0.03) and 30-m sprint time (r=-0.76, p=0.02). Muscle strength had non-significant correlation to drop jump (r=0.32, p=0.40) and vertical jump (r=0.40, p=0.28) performance.  Drop jump performance showed significant correlation with top running speed (r=0.72, p=0.03); similar correlation was not observed between vertical jump and top running speed (r=0.55, p=0.13). Sprints and jumping ability did not show a significant correlation; vertical jump and 10-m (r=-0.10, p=0.79), 20-m (r=-0.21, p=0.59) and 30-m sprint time (r=-0.31, p=0.42) respective drop jump and 10-m (r=-0.40, p=0.28), 20-m (r=-0.46, p=0.21) and 30-m sprint time (r=-0.55, p=0.13). Conclusion These results, with support from earlier research, indicated that greater lower body strength (quantified by 3 RM squat) was related to better top running speed and 10-m, 20-m and 30-m sprint time in female soccer players. On the other hand, jumping ability had a non-significant correlation to muscle strength, sprint time or top running speed, with the exception of drop jump performance and top running speed that had a strong correlation. / Introduktion Kvinnliga fotbollsspelare behöver träna allsidigt för att klara av de krav som finns under en fotbollsmatch. Det finns flera studier utförda på samband mellan styrka och hopp- och sprintförmåga. De flesta studier är däremot utförda på manliga idrottare.   Syfte Syftet med studien var att undersöka samband mellan styrka, hopp- och sprintförmåga hos elitidrottsaktiva kvinnliga fotbollsspelare.  Metod Nio (n=9) kvinnliga fotbollsspelare på elitnivå i Sverige tackade ja till att delta i studien. En kvantitativ ansats i form av tvärsnittsstudie användes för att svara på studiens syfte. Deltagarna utförde ett vertikalhopptest, ett drop jump, ett 55 meters sprinttest och ett tre repetition maximal (3 RM) knäböjstest. Datainsamlingen skedde vid två olika tillfällen varav ena var på en friidrottsanläggning för sprint och hopptester och andra i ett gym för knäböjstest.  Resultat Resultatet observerade att 3 RM skivstångsknäböj hade en stark signifikant korrelation med topphastighet (r=0,77, p=0,15) och acceleration 10 m (r=0,66, p=0,05), 20 m (r=-0,73,p=0,03) och 30 m (r=-0,76, p=0,02) och hade en svagare icke-signifikant korrelation med drop jump (r=0,32, p=0,40) och vertikalhopp (r=0,40, p=0,28). Topphastighet hade en signifikant korrelation med drop jump (r=0,72, p=0,03), liknande samband observerades inte med vertikalhopp (r=0,55, p=0,13). Hopptesterna noterade ingen signifikant korrelation till acceleration i studien; vertikalhopp och acceleration 10 m (r=-0,10, p=0,79), 20 m (r=-0,21, p=0,59) och 30 m (r=-0,31, p=0,42) respektive drop jump och acceleration 10 m (r=-0,40, p=0,28), 20 m (r=-0,46, p=0,21) och 30 m (r=-0,55, p=0,13). Slutsats Resultatet i studien ger en indikation till att högre relativ benstyrka, mätt med knäböj, har ett starkt samband till högre topphastighet och snabbare accelerationer upp till 30 m. Hoppförmåga har svagare samband med både styrka, acceleration och topphastighet. Undantag drop jump-test och topphastighet som har en stark korrelation.

SyfteDenna studies syfte var att undersöka om det finns ett samband mellan mellantid och sluttid på sprint prologer för herrar i världscuptävlingar, samt undersöka om förklaringsgraden för detta samband skiljer sig mellan tävlingsbanor med olika banprofil baserat på antal höjdmeter fram till mellantiden (CTC).MetoderAnalysen gjordes genom att ladda ner samtliga resultat från prologer från världscupen innehållande en mellantid efter 500-1000 m från säsongen 2017/2018 till 2019-2020. Sluttid, slutplacering och tid och placering vid mellantidsstation användes i den statistiska analysen. CTC beräknades genom att dividera klättrade höjdmeter från start till mellantid med respektive banas distans från start till mellantid. Baserat på olika banors CTC delades banorna in i 2 grupper, Level 1 (L1) banor med CTC ≤ 0,040 m/m och Level 2 (L2) CTC &gt; 0,040 m/m. För att bestämma om datan var normalfördelad användes Kolmogorov-Smirnov test. Datan analyserades sedan med hjälp av Pearsons korrelation för att beräkna korrelationskoefficienten (r) vilken sedan kvadrerades för att få förklaringsgraden (r2).ResultatKorrelationsanalysen som genomförts visar ett signifikant resultat mellan mellantid och sluttid för alla analyserade prologer (0,63 &lt; r &lt; 0,95; alla p &lt; 0,001). Mellantiden förklarar 76 ± 12 % av variationen i sluttid, men ingen signifikant skillnad sågs för förklaringsgraden mellan tävlingsbanor med olika CTCSlutsatserSlutsatserna som kan dras av denna studie är att ett bra resultat vid mellantiden med stor sannolikhet kommer ge ett bra slutresultat, oberoende av banprofil. Framtida forskning behövs för att utvärdera vilken taktik åkarna väljer. / PurposeThe aim of this present study was to investigate if there is any correlation between intermediate station time and finish time in men’s cross-country ski sprint World Cup prologue. The second purpose was to identify if the correlation could depend on the morphology of the analysed courses. Methods Analyses were made on sprint prologues in World Cup, involving an intermediate time after 500-1000m from season 2017/2018 to 2019-2020. Intermediate time and finish time were used in statistical analysis. A coefficient of terrain characteristics (CTC) was calculated by dividing the high difference (HD) from the start to the position of the intermediate time station by the respectively covered distance. Based on CTC the different courses were categorized in two groups. Leve 1 (L1) courses with a CTC ≤ 0,040 m/m and Level 2 (L2) courses with a CTC &gt; 0,040 m/m. To identify if data were normally distributed Kolmogorov-Smirnov test was used. The data were analysed using Pearson’s correlation to calculate the coefficient of variation (r) which was then squared to obtain the coefficient of determination (r2).ResultsThe correlation analysis shows that there were significant relationships between intermediate time and finish time for all analysed sprint prologues (0,63 &lt; r &lt; 0,95; all p &lt; 0,001). Intermediate time explains 76 ± 12 % of the variation in finish time, while no significant difference was seen for the determination coefficients between race tracks with different CTCConclusionsFast times at the intermediate time stations will most likely give good finish times, independent of terrain characteristics (CTC). Further researches are needed to evaluate which pacing profile skiers are using.

As a sprint canoe athlete takes a stroke, the flow around their blade governs the transfer of power from the athlete to the water. Gaining a better understanding of this flow can lead to improved equipment design and athlete technique to increase the efficiency of their stroke. A method of modelling the complex motion of the sprint canoe stroke was developed that was able to simulate the transient 2-phase blade-water interactions during the stroke using computational fluid dynamics (CFD). The blade input motion was determined by extrapolating the changing blade position from video analysis of a national team athlete. To simulate the blade motion a rigid inner mesh translated and rotated according to the extrapolated blade path while an outer mesh deformed according to the translation of the inner mesh; allowing for independent motion of the blade throughout the xy-plane. Instabilities associated with the blade piercing a free surface were dealt with by using a piecewise solution. The developed model provided a first look into the complex hydrodynamics of the sprint canoe stroke. Examination of the resultant flow patterns showed the development and shedding of tip and side vortices and the resultant pressure on the blade. Late in the catch, there was an unrealistic drop in the net force on the blade which was attributed to the over-rotation of the blade causing the top two-thirds of the blade to accelerate the near surface water forward. The inclusion of an approximated shaft flexibility showed the ability to improve the net force to more realistic values. / Thesis / Master of Applied Science (MASc)

Aim The aim of this study was to ascertain the effect of resisted sprint training in swimming on maximal swimming velocity and performance characteristics. The aim was also to examine how maximal swimming velocity is related to maximal swim power and maximal dry-land power. Method Eighteen competitive national level swimmers (9 male and 9 female; age: 18.3 ± 2.3 years, body mass: 72 ± 8.3 kg, height: 177.2 ± 4.6 cm, mean ± SD) were recruited to this study. Subjects were assigned to either resisted sprint training (RST) or unresisted sprint training (UST). Sprint training was performed two times per week during 6 weeks as 8x15m with a 2min send-off interval. RST performed sprint training using individualized load corresponding 10% of maximum drag load (L10), UST performed sprint training with no added resistance. A test-battery including dry-land strength assessment; maximal strength (MxS) and explosive strength (ExS), a timed 25m front-crawl swim and in-water force-velocity profiling was performed prior and following the training intervention. Maximal swim power (Pmax), maximum drag load (F0), theoretical maximum velocity (v0) and slope of force-velocity curve (SFv) was computed though force-velocity profiling. Results No significant within group differences occurred in neither RST nor UST following the 6-week intervention period in: swimming velocity, MxS, ExS, Pmax, F0, v0, and SFv. Strong correlations were found between swimming velocity and MxS (r = 0.75), ExS (r =0.82) and Pmax (r = 0.92). Conclusion Resisted sprint training in swimming using L10 did in the present study not elicit any improvements in maximal swimming velocity or examined performance characteristics. Resisted sprint training does not appear to be a superior method of improving swimming performance compared to unresisted sprint training. MxS, ExS and Pmax can be used as robust predictors of swim performance, however only Pmax was found to be casually related to swimming velocity.

Background: Small-sided games are frequently used as a training method in today´s football. The importance of the ability to perform high-intensity running is increasing and small-sided games may not lead to the required improvement of this ability. It might be necessary to add speed-endurance training to obtain the high-intensity running. Objective: The aim of this study was to investigate which of the training methods; small-sided games or speed-endurance training, leads to the highest performance improvements in three football-specific tests. Measures and Methods: The study was an intervention study where 31 male football players participated. They were randomized in to two groups which performed either speed-endurance training (SEP) (n=16) or small-sided games (SSG) 6 vs 6 (n=15). The study lasted four weeks and eleven sessions in total. Baseline tests and posttraining test were conducted in Yo-Yo IR2, Arrowhead agility test and Repeated sprint 30 meters. Result: SEP demonstrated an 17 % higher increase in testresults than SSG in Yo-Yo IR2. No significant difference between the groups were observed in the other tests. Conclusion: Small-sided games is a training method which entails football-specific training load. It might be necessary to add speed-endurance training which can lead to higher performance improvments in Yo-Yo IR2.