Syfte och frågeställning Syftet med studien är att undersöka om det finns ett samband mellan hopptiden på mark och hopptiden i det tekniska hoppet Flip på is för konståkare. Det sekundära syftet är att undersöka om det finns ett samband mellan hopptiden i tekniska hopp på is och antal år i idrotten samt ålder. Finns det en korrelation mellan countermovement jump med armar (CMJa) på mark och tekniska hoppet Flip på is hos konståkare? Finns det en korrelation mellan hopptiden i Flip och antal år i idrotten samt ålder? Metod En kvantitativ metod användes för att få fram försökspersonernas hopptid på is och mark. 11 stycken konståkare medverkade i studien, 6 kvinnor och 5 män (20,9 ± 3,1 år). Försökspersonerna var skadefria, friska och hade fyllt 15 år. Ett krav för deltagande var att försökspersonerna utövat idrotten i minst åtta år samt att de kunde utföra en enkel Flip. Vid själva testtillfället fick försökspersonerna börja med att utföra tre stycken enkel Flip på is medan deras hopp filmades. Försökspersonerna fick sedan utföra tre stycken CMJ(a) där deras hopptid registrerades med hjälp av Ivarjump system. Resultat Resultatet visar på att det inte finns något samband i hopptiden mellan CMJ(a) och Flip(r = 0,17, p= 0,602 ). Det fanns inte heller något samband mellan hopptiden i Flip och ålder. Däremot påvisar resultatet att det finns en korrelation mellan hopptiden i Flip och antal år i idrotten (r = 0,821, p = 0,02). Slutsats Slutsatsen med studien är att det inte finns något samband mellan hopptid på mark och på is. Forskningsläget är fortfarande relativt litet område och fler studier behöver göras. Flertal studier menar att maximalstyrka i ben korrelerar med hopphöjden på mark men eftersom det inte finns en korrelation mellan hopptiden på mark och is behöver det göras mer studier som undersöker sambandet mellan maximalstyrka och hopptid på is. Resultatet visade även på att sambandet mellan antal år i idrotten (erfarenhet) och hopphöjd på is var stor. De tekniska färdigheterna verkar vara den dominerande faktorn för att kunna utnyttja benstyrkan i hoppen

The popularity of soccer throughout the world has led to the demand for a scientific approach to the preparation of players for competitive matches. Although previous researchers have attempted to understand the training demands undertaken by soccer players, limited information is known regarding the structure of training in soccer. At present research has focused on the frequency and duration of soccer training without using both objective and subjective measures of training load to systematically evaluate training practices in elite teams. Little is also known regarding the periodisation strategies employed by elite soccer teams across a competitive season and whether they follow traditional models of periodisation. With this in mind, the primary aim of this thesis is to therefore characterise the current training periodisation practices that exist in elite soccer using applied methods of training load assessment. The aim of the first study (Chapter 3) was to evaluate the use of Global Positioning Devices (GPS) for the measurement of soccer-specific activities to provide objective data for training load assessment. Findings from this study were applied to study 3 (Chapter 5) of the thesis. Firstly, a soccer-specific movement course was designed based on the movements exhibited by an elite soccer player during a competitive match using a multi-camera tracking system (ProZone®). Two moderately trained males performed 10 bouts of the soccer-specific track following familiarisation and a 10 minute standardised warm up. Both subjects wore two 10Hz GPS units inside a custom-made vest during all bouts of the track to determine both reliability and inter-unit reliability of the GPS devices. Data analysis revealed the reliability of the GPS devices was good for distance covered at lower velocities (0 – 4 m/s; CV% = 0.6 – 3.6%). However when the velocity of movement increased (> 4 m/s), the reliability of the units decreased (mean change from 13.8 to 33.6 CV%). Both total distance (mean CV% = 1.1%) and max speed (mean CV% = 2.7%) were both found to be highly reliable variables. However the devices demonstrated high levels of inter-unit reliability error due to an increase in systematic error with random distribution of data points between both devices for all variables measured. The data suggested that 10Hz GPS devices are reliable for the measurement of lower velocity (0 – 4 m/s) running. However, care must be taken when analysing data in higher velocity bands (> 4 m/s) due to the high ii error rates observed. The high inter-unit reliability error also suggests that 10Hz GPS devices cannot be used interchangeably between players in order to minimise the associated error. The aim of the second study (Chapter 4) was to quantify the reliability and validity of a portable vertical jump assessment tool (Optojump®) for use in the applied setting. Vertical jump assessment was utilised as a measurement tool to analyse the effect of training load on the neuromuscular system that was evaluated in study 4 (Chapter 6) of the thesis. Eleven healthy male subjects were familiarised to perform four separate common types of vertical jump test: countermovement with arm swing (CMJ-W), countermovement without arm swing (CMJ-WO), squat jump (SJ) and drop jump (DJ). Contact time, flight time and jump height were selected as variables for the study. For reliability assessment, all subjects performed 3 efforts of each jump type across 5 identical testing sessions (separated by minimum of 2 days). For validity assessment, subjects were asked to perform the same jump modalities as the previous investigation on one occasion while data was simultaneously collected from both a force plate (criterion instrument) and the Optojump photocells. The data revealed the Optojump device was highly reliable for the assessment of jump flight and height for CMJ-W, CMJ-WO, SJ and DJ (all CV% = 3.2 and 5.6%). However reliability of the device was reduced for the measurement of contact time with the DJ (CV% = 13.9%). Validity data revealed that all jump types and variables were highly valid in comparison to the force plate criterion measure (SEE% = < 1%, Pearsons correlation = r > 0.99). This study revealed that the Optojump device is highly reliable and valid for all jump types and variables, with the exception of contact time for DJ. Therefore the Optojump system may be used with confidence to detect within-group changes in applied assessments of vertical jump performance. Due to the high cost and lack of portability of laboratory-based force plates, the Optojump system is a viable alternative for accurate jump measurement and neuromuscular assessment. The CMJ-WO jump assessment was chosen for study 4 for comparison with previous research. The aim of the third study (Chapter 5) was to quantify the periodisation strategies employed by an elite professional soccer team throughout a competitive season. Training load data was collected from 37 elite outfield soccer players at one professional English soccer team over a 45 week period during the 2011-2012 domestic season. All players wore iii global positioning system (GPS) devices, heart rate (HR) belts and were asked to provide a rating of perceived exertion (RPE) for each training session to generate training load data. Players were assigned to one of 5 positional groups: central defender (CD), wide defender (WD), central midfielder (CM), wide midfielder (WM) and attacker (AT). The data was separated into the pre-season (6 weeks duration) and in-season (39 weeks duration) phases in order to investigate specific training periods recognised within the annual plan. The pre-season phase was further separated into weekly blocks for analysis of the structure employed in each specific microcycle. The in-season phase was divided into 6 x 6 week blocks for analysis of mesocycle structure. Within the in-season data, three separate microcycles (weeks 7, 24 and 39) were selected consisting of the same weekly training schedules to determine whether differences in microcycle training load pattern existed. In addition, the training data within a given microcycle was analysed to investigate the loading patterns in relation to number of days away from the competitive match fixture. Linear mixed modelling analysis revealed significant differences for total distance and average HR (P < 0.05) between period 1 with periods 3 and 6 during training mesocycles. However no differences were found for the remaining training variables during both pre-season and in-season microcycles (P > 0.05). Training load variables were significantly reduced on match day (MD) -1 (P < 0.05) but remained similar across MD-2, MD-3 and MD-5 (P > 0.05) during in-season microcycles. CM players generally covered the most total distance compared to other positions. Defenders reported higher internal load values (average HR and RPE) compared to attackers during in-season training phases but such differences were not evident during pre-season. This study revealed that training load doesn’t appear to be systematically periodised across a competitive season in an elite soccer team. This may have practical implications for training planning, as monotonous training load prescription may lead to maladaptation in soccer players during a competitive season. This was the first study to systematically evaluate periodisation strategies in an elite soccer team, but further work is required to determine such practices at different soccer teams. The aim of the fourth study (Chapter 6) was to determine the neuromuscular response to a microcycle of soccer training in elite soccer players using vertical jump assessment via the Optojump device. Nine elite level youth soccer players from an U18 soccer academy team were recruited for the study. The players underwent four separate on-field soccer training sessions following familiarisation of all testing procedures.

Bakgrund: Inom flera idrotter såsom fotboll, basket och innebandy är en bra sprintprestation viktigt. Sprintprestation påverkas av många olika faktorer. I litteraturen har det noterats en stark korrelation mellan prestation i vertikala och horisontella hopp och sprintprestation. Dessutom har flera studier påvisat hur prestation i Isometric Mid-Thigh Pull (IMTP), som är en form av test av maximal statisk styrka i ben- och ryggmuskulaturen, har en måttlig eller stark korrelation med sprintprestation. Enligt författarnas kännedom har ingen studie undersökt korrelationen mellan sprintprestation och variablerna hopphöjd, hopplängd, Rate of Force Development (RFD), Relativ Power (RP) samt Peak Force (PF) hos unga manliga innebandyspelare. Syfte: Syftet med studien är att undersöka korrelationen mellan sprintprestation och prestation i IMTP-test och hopprestation hos unga manliga innebandyspelare. Metod: Deltagarna bestod av nio unga manliga innebandyspelare; 16 ± 1 år, 73,2 ± 6,5 kg och 179 ± 7 cm, som genomförde tester bestående av 20-metersprint, stående längdhopp, Countermovement Jump (CMJ) och IMTP. Resultat: Icke-signifikanta måttligt starka korrelationer noterades mellan sprintprestation och hopprestation (hopphöjd i CMJ, r=-0.455, p=0.219; hopplängd i stående längdhopp, r=-0.467, p=0.205; RP (w/kg) i CMJ, r=-0.356, p=0.348). Ingen av de övriga testresultaten (RFD och PF i IMTP-test) korrelerade med sprintprestation. Slutsats: Måttligt starka, icke-signifikanta korrelationer observerades mellan sprintprestation och hopprestation (hopphöjd i CMJ, hopplängd i stående längdhopp, RP (w/kg) i CMJ. Att de måttligt starka sambanden inte blev statistiskt signifikanta beror troligtvis på att studien hade för få deltagare (n=9). Det fanns ingen korrelation mellan sprintprestation och övriga variabler (RFD och PF i IMTP). Framtida forskning inom ämnet bör genomföras på ett större urval för att kunna få resultat med statistisk signifikans. / Background: Within several sports such as football, basketball and floorball sprint performance is an important ability. Sprint performance is influenced by a variety of factors. Previous literature has demonstrated that there may be a strong correlation between performance in vertical and horizontal jumping and sprint performance. In addition, several studies have shown how performance in Isometric Mid-Thigh Pull (IMTP), which is a form of test of maximal static strength in the leg and back muscles, has a moderate or strong correlation with sprint performance. However the authors found no study that has examined the correlation between sprint performance and the variables jump height, jump length, RFD, RP and PF among young male floorball players. Aim: The aim of this study was to examine the correlation between sprint performance and performance in IMTP-test and jump performance among young male floorball players. Method: The participants in this study consisted of 9 young male floorball players; 16 ± 1 years, 73,2 ± 6,5 kg och 179 ± 7 cm, that performed a variety of tests; 20 meter sprint, standing long jump, Countermovement Jump (CMJ) and IMTP. Results: Non-significant moderately correlations were noted between sprint performance and jump performance (jump height in CMJ, r=-0.455, p=0.219; jump length in standing long jump, r=-0.467, p=0.205; RP (w/kg) in CMJ, r=-0.356, p=0.348). None of the other test results (RFD and PF in IMTP-test) correlated with sprint performance. Besides that none of the test results had a correlation with a statistical significance. Conclusion: Moderately strong, non-significant correlations were observed between sprint performance and jump performance (jump height in CMJ, jump length in standing long jump, RP (w/kg) in CMJ). The relatively low number of participants (n=9) in this study may explain why the moderately strong relationships betweeen sprint and jump performance did not become statistically significant. There was no correlation between sprint performance and the other variables (RFD and PF in IMTP). Future research should be conducted on a larger sample in order to obtain results with statistical significance.

Bakgrund: För en del idrottare är det viktigt att bibehålla en hög effektutveckling och anaerob kapacitet under en hel tävling. Ibland tillåts endast någon timmes återhämtning mellan prestationer, och nutritionsmässiga strategier, däribland intag av kolhydrater blir relevant för att underlätta återhämtningsprocessen. Syfte: Syftet med denna studie var att undersöka effekten av kolhydratsintag under 1h återhämtning från kortvarig högintensiv träning på efterföljande anaerob prestationsförmåga. Metod: Åtta vältränade kvinnor och män utförde ett countermovement jump (CMJ) följt av 5 varv av Wingate cykeltest. Deltagare fick därefter vila i 1 timme och intog under tiden antingen 1.2g/kg kolhydrater (maltodextrin) eller placebo. Efter återhämtningen utförde deltagarna ett CMJ följt av 1 varv Wingate cykeltest. Testvärden som mättes var hopphöjd (CMJ), min power, max power, average power samt fatique index (Wingate). Resultat: Resultatet från två-vägs ANOVA visade att varken tid eller supplementering hade någon signifikant effekt på prestation gällande någon av de uppmätta variablerna. Det var ingen signifikant skillnad mellan det första varvet Wingate före återhämtning jämfört med Wingate efter återhämtning, samma gäller CMJ. Båda grupper återhämtade sin ursprungliga prestationsförmåga efter 1h återhämtning, vare sig de intog kolhydrater eller inte. / Background: For some athletes it is important to maintain a high level of power output and anaerobic capacity throughout an entire compentition. Some situations only allow a few hours of recovery between performances, and nutritional strategies, including carbohydrate intake become relevant to facilitate the recovery process. Purpose: The purpose of this study was to investigate the effect of carbohydrate intake during 1 hour of recovery from short-term high intensity exercise on subsequent anaerobic performance. Method: Eight well-trained women and men performed a countermovement jump (CMJ) followed by 5 laps of Wingate cycling test. Participants were then allowed to rest for 1 hour while consuming either 1,2g/kg carbohydrates (maltodextrin) or placebo. After recovery, participants performed a CMJ followed by one lap of Wingate cycling test. The testvalues that were measured were jump height (CMJ), min power, max power, average power and fatigue index (Wingate). Result: Results from the two-way ANOVA showed that neither time nor supplementation had any significant effect on subsequent performance regarding any of the measured variables. There were no significant difference between Wingate lap 1 pre recovery and Wingate post recovery, same for CMJ. Both groups regained their original performance after 1h of recovery, wether intake of carbohydrate or not.

Youth soccer players are required to play multiple matches within a short period of time. Participation in congested match schedules like youth soccer tournaments can result in fatigue and a decline in physical performance. The purpose of this study was to examine changes in countermovement jump height variables and sprint time to determine if physical performance was altered. Fourteen youth female soccer players performed countermovement jump testing pre, post-match, and post-tournament, and sprint testing pre and post-tournament. Jump height differed significantly (p

I denna översiktsartikel granskades 17 randomiserade kontroll studier som undersökt hur excentrisk träning har påverkat hopphöjd, muskelstyrka och effektutveckling hos tränade och skadefria individer, med mål att svara på följande två frågeställningar; 1) ”Är excentrisk träning ett effektivt sätt att träna för att utveckla hopphöjd, muskelstyrka och effektutveckling för tränade och skadefria individer?” 2) ”Om det är det, hur bör denna träning i så fall se ut?”. Majoriteten av insamlade studier kunde inte urskilja några signifikanta förändringar till följd av excentrisk träning. Endast sex av 17 studier kunde påvisa akuta såväl som kortsiktiga signifikanta förbättringar av hopphöjd, muskelstyrka och effektutveckling. Dock ifrågasätts relevansen av dessa fynd då effektstorleken inte rapporterats i alla studier samt att utformningen av studierna varierat från en studie till en annan. Sammantaget lyckades inte de granskade studierna bevisa att excentrisk träning är en effektiv metod för att utveckla hopphöjd, muskelstyrka och effektutveckling hos tränade och skadefria individer. / In this review 17 randomized control studies were reviewed that had examined the effects of eccentric training regarding jump height, strength and power for trained and non-injured individuals. The purpose of the review was to answer the following two questions at issue; 1) “Is eccentric training an efficient method to enhance jump height, strength or power for trained and non-injured individuals?” 2) “If so, how should that training regime be designed?”. Most of the included studies could not distinguish any significant changes because of eccentric training. Only six out of 17 studies could show acute as well as short term significant improvements in jump height, strength and power. The relevance of these findings is questioned since effect size has not been reported in all the included studies. The variety between the different interventions in each study also makes it difficult to compare the results between one study and another. In conclusion, the reviewed studies failed to show that eccentric training is an effective method to enhance jump height, strength and power for trained and non-injured individuals.

Syfte: Syftet för studien var att undersöka om isometric mid-thigh pull (IMTP) tillsammans med (CMJ) kan anses som lämpliga testmetoder för att mäta prestation i hoppförmåga inom parkour/freerunning (PK/FR). Vi undersökte detta genom att mäta traceurers maximala styrka och explosiva styrka i de nedre extremiteterna, för att sedan jämföra resultaten med fysiskt aktiva idrottsstudenter på högskolenivå. Vi undersökte även om IMTP och CMJ korrelerar med varandra. Urval: 23 personer, 11 traceurer och 12 fysiskt aktiva idrottare rekryterades för denna studie. Metod: vi mätte maximal styrka: Peak force (PF) IMTP (N) på kraftplatta och maximal vertikal hopphöjd: CMJ (cm) på IR-matta. Statistisk analys: Shapiro Wilks användes för normalfördelningar, en oberoende tvåvägs Mann-Whitney U t-test användes för att undersöka skillnader mellan grupperna. Två Spearmans- och ett Pearsons korrelationskoefficienttest användes för att undersöka samband mellan IMTP och CMJ. Resultat: PK gruppen var normalfördelad i alla variabler IMTP (N) och CMJ (cm) men kontroll (KTRL) gruppen var ej normalfördelad i CMJ (cm) och gav utslag för IMTP (N). PK gruppen uppnådde ett IMTP (N) medianvärde på: 2269,9 ± 661.72N och CMJ medianvärde på 36.2 ± 7.48 cm. KTRL gruppen uppnådde ett IMTP (N) medianvärde på: 1626.9 ± 501.95N och ett CMJ medianvärde på: 31.8 ± 5.91cm. Ingen statistiskt signifikant skillnad hittades mellan grupperna, men traceurerna visar en trend för ett högre IMTP (N) värde. Ett statistiskt signifikant samband fanns mellan IMTP och CMJ för hela populationen. R-värde = 0.404. R² värde avrundades till 23%. P-värde = 0.031. Inget statistiskt signifikant samband fanns för PK eller KTRL grupperna individuellt. Slutsats: Traceurerna och de fysiskt aktiva högskolestudenterna visade snarlika resultat i maximal styrka och explosiv styrka i denna studie. Resultaten klassificerades som lågpresterande i förhållande till referensvärden från tidigare studier på traditionella idrotter för IMTP och på traceurer i CMJ. Den maximala styrkan från IMTP tycks förklara 23% av hoppförmågan i CMJ vilket kan vara en indikation av betydelse för traceurers prestation. Framtida forskare uppmuntras använda IMTP och CMJ på större populationer för att kartlägga traceurers force-velocity kurvor och/eller inrätta skadepreventiva program för PK/FR. Begrepp: Traceur (FRE) = tracer (ENG), spårare (SWE). Traceur = manlig Parkour utövare. Traceuse = kvinnlig Parkourutövare. PK/FR = Parkour/Freerunning. PK = Studiens Parkour grupp. KTRL = Studiens kontrollgrupp. Countermovement jump (CMJ), (N) = Newton. 1RM = en 100% maximal ansträngd repetition. / Purpose: The aim of the study was to investigate if IMTP together with CMJ can be considered as suitable methods to measure performance in jumping ability in PK/FR. We investigated this by measuring maximal strength and explosive strength of the lower extremities of traceurs and comparing the results with physically active college student athletes. We investigated also if IMTP and CMJ correlate with each other. Recruitment: 23 people, 11 traceurs and 12 psychical active collegial sport athletes were recruited for this study. Method: We measured maximal strength: PF IMTP (N) on force plate and maximal vertical jump height: CMJ (cm) on IR mat. Statistical analysis: Shapiro Wilks was used for normal distribution; an independent two-way Mann-Whitney U t-test was used to examine differences between groups. Linear regression tests with two Spearman's and one Pearson's correlation coefficient tests were used to examine relationships between IMTP and CMJ. R² values were calculated. Results: The PK group was normally distributed in IMTP (N) and CMJ (cm). The KTRL group was not normally distributed in CMJ (cm) and flagged an indication for IMTP (N). The PK group achieved a IMTP (N) median of 2269.9N SD ± 661.72N. And CMJ median of 36.2cm SD ± 7.48cm. The KTRL group achieved a IMTP (N) median of 1626.9N SD ± 501.95N. And a CMJ median of 31.8cm SD ± 5.91cm. No statistically significant differences were found between the groups. But the traceurs showed a trend for a higher IMTP (N) value. A statistically significant relationship was found between IMTP and CMJ for the entire population. R value = 0.404. R² value was rounded to 23%. P-value = 0.031. No statistically significant relationships were found for the PK- or the KTRL groups individually. Conclusion: The traceurs and the physically active college students were similar in maximal- and explosive strength in this study. The results were classified as low performance in comparison to previous studies of traditional sports on IMTP and on traceurs on CMJ. The maximal strength from the IMTP appears to account for 23% of the jumping ability in CMJ which may be an indication of importance for traceurs performance. Future researchers are encouraged to use IMTP and CMJ on larger populations to map force-velocity curves and/or establish injury prevention programs for PK/FR. Concepts: Traceur (FRE) = tracer (ENG), tracker (SWE). Traceur = male Parkour practitioner. Traceuse = female Parkour practitioner. PK/FR = Parkour/Freerunning. PK = The study's Parkour group. KTRL = Study control group. Countermovement jump (CMJ), Isometric mid-thigh pull (IMTP). 1 RM = a 100% maximum effort repetition. / <p>Ämneslärarprogrammet, Specialidrott</p>

Title: A comparison of dynamic abilities in nordic ski disciplines Aim: This dissertation aims to compare the dynamic abilities of cross country skiers and ski jumper in age between 12 to 15. Clarification of whether or not a training process of those two athlete groups has a crucial impact on the development of mentioned abilities compared to the other hobby sports group (target group). Methodology: This dissertation is conceived as empiric-theoretical. It analyses the results of samples to verify the hypothesis. There were three groups consisting of 10 samples (athletes) in total. The samples were tested in horizontal jumps (long jump, triple jump, multiple jumps) and vertical jumps (squat jump, counter movement jump). In all tests, it was decided to use only the best of all three attempts for the results. Findings: Development of dynamic abilities during the training process has a positive impact on their development in general. Both cross country skiers and ski jumpers achieved better results than the target group. Furthermore, ski jumpers performed better than cross country skiers. Keywords: physical health, sport performance, cross country skiing, ski jumping, squat jump (SJ), countermovement jump (CMJ), long jump, triple jump, multiple jumps

Bakgrund: Syftet med denna studie var att undersöka effekten av sju dagars tillskott av betain (2,5 gram/dag) på prestationsförmågan i idrottsspecifika tester för manliga vältränade cykelatleter. Metod: Sex (n=6) manliga testpersoner (genomsnitt ± standardavvikelse ålder, 31,7 ± 10,2 år; längd, 188,2 ± 3,6 cm; kroppsvikt; 82,5 ± 7,6 kg; fettfri massa, 71,6 ± 7,3 kg) genomförde förtester bestående av fem counter movement jumps, fyra stycken 12 s wingate-sprinter med 2,5 minuters aktiv vila följt av fem ytterligare counter movement jumps. De blev sedan indelade slumpmässigt i betain- eller placebogrupper. Första testet etablerade basvärden och eftertest ”1” samt ”2” föregicks med antingen sju dagars tillskott med placebo (2,5 g maltodextrin plus 12,5 mg riboflavin) eller betain (2,5 g trimetylglycin plus 12,5 mg riboflavin). Riboflavin användes för att undanröja den fiskliknande doften som kan uppstå vid tillskott av betain. Doseringen bestod av fyra kapslar per dag till måltid, varav två kapslar intogs på morgonen eller förmiddagen (före träning) och två kapslar intogs på eftermiddagen eller kvällen (efter träning). Vi använde oss av en dubbelblindad, kontrollerad randomisering cross-over design; med en veckas washout mellan placebo och betain. Maximum Peak Power, Average Peak Power, Maximum Average Power, Mean Average Power, Mean Relative Power Drop, Maximum Relative Power Drop, CMJ-Medel och CMJ-Max före och efter sprinterna analyserades med two-tailed t-test 2 och 3 för att jämföra skillnader före och efter intag av tillskott samt skillnaderna mellan grupperna.Resultat: Inga signifikanta skillnader kunde noteras. Konklusion: En veckas tillskott av betain gav inte någon signifikant förbättring jämfört med placebo i hopp- och sprintförmåga samt förmåga att ta ut sig själv maximalt hos aktiva cyklister. Fler studier med framförallt större testgrupper efterlyses för att utvärdera betainets ergogena effekt bland aktiva atleter. / The effect of betaine supplementation on counter movement jumps and sprint performance among male bicycle athletes Background: The purpose of this study was to investigate the effect of a seven days supplementation regimen with betaine (2,5 grams per day) on counter movement jumps and sprint performance in trained male bicyclists. Method: Six (n=6) male subjects (mean ± standard deviation age, 31,7 ± 10,2 years; height, 188,2 ± 3,6 cm; bodyweight, 82,5 ± 7,6 kg; lean body mass, 71,6 ± 7,6 kg) completed a 21 day study involving five counter movement jumps (no arm swing) followed by 4 consecutive modified 12 second Wingate sprints on a bicycle ergometer with active rest (2,5 minutes) followed by another set of five counter movement jumps. A double blind, controlled randomized cross over design was used and there was a 1 week washout between the supplementation startup for each group. Following pre-testing (baseline) the participants were randomly divided into groups by choosing one of the following supplements: “12” Placebo –2,5 grams of maltodextrine plus 12,5 mg riboflavin or “11” – Active 2,5 grams of trimethylglycine plus 12,5 mg riboflavin. Riboflavin was used so mask the “fishy odor syndrome” effect of high intakes of trimethylglycine that may cause trimethyluria. Daily consumption of capsules was divided into two doses of two capsules each with meals. One dose (two capsules) was consumed in the morning and one dose in the evening. The following variables were analyzed: Maximum Peak Power, Average Peak Power, Maximum Mean Power, Average Mean Power, Maximum Relative Power Drop, Average Relative Power Drop, Mean CMJ-Pre + Post sprints and Maximal CMJ-Pre + Post sprints. Results: None of the parameters showed statistical significance. Conclusion: Our study indicates that seven days of betaine ingestion does not seem significantly improve counter movement jump or sprint capacity in male trained bicyclists. Larger studies are needed to investigate the performance enhancing effects of betaine, especially among high performance athletes.