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  • 1.
    Adler, Daniel
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Analys av gjorda och insläppta mål över matchtid i herrallsvenskan i fotboll2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den ultimata indikatorn på ett fotbollslags prestation är matchresultatet som beror på balansen av gjorda och insläppta mål. Syftet med studien var att analysera de allsvenska herrlagens målproduktion under säsongen 2010. Detta för att undersöka de svenska elitlagens förekomst av gjorda och insläppta mål över matchtid. Ytterligare syfte var att undersöka om framgångsrika och mindre framgångsrika lag uppvisar olika mönster gällande dessa parametrar. Samtliga 240 matcher, totalt 600 mål, från säsongen 2010 studerades på förekomst av mål över matchtid. Målen kategoriserades lagvis i åtta stycken tidsperioder. Lagen delades även in i tre olika grupper beroende på tabellplacering. Resultaten baserat på samtliga lag visade signifikant större andel gjorda mål under den andra halvleken jämfört med den första, 55,2% mot 44,8% (p<0,05). Inga signifikanta skillnader mellan 15-minutersperioderna kunde ses. Däremot sågs signifikanta skillnader mellan 15-minutersperioderna inom de olika grupperna. Topplagen uppvisade signifikant större andel insläppta mål under period 76-90min jämfört med 31-45min, 46-60min och 61-75min (p<0,05). Mittenlagen uppvisade signifikant mindre andel insläppta mål under period 76-90min jämfört med 31-45min, 46-60min och 61-75min (p<0,05). Sammanfattningsvis, svenska herr-elitlag följde en ökande trend av gjorda mål över matchtid med större andel mål under andra halvleken jämfört med första. Resultaten antydde även att topplagen uppvisade hög resultatmässig prestation genom hela matcherna medan bottenlagen uppvisade låg prestation och mittenlagen varierande prestation, vilket delvis förklarar varför grupperna placerar sig i toppen, botten och mitten av tabellen.

  • 2.
    Agnerling, Emma
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Kombinationen av bikarbonat- och koffeinsupplementering förbättrar löpprestation i ett Beep-test2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 3.
    Ainegren, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Roller skis' rolling resistance and grip characteristics: influences on physiological and performance measures in cross-country skiers2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The aim of this thesis was to investigate roller ski characteristics; classical and freestyle roller skis’ rolling resistance coefficients (μR) and classical style roller skis’ static friction coefficients (μS), and to study the influence of different μR and μS on cross-country skiers’ performance and both physiological and biomechanical indices. The aim was also to study differences in skiing economy and efficiency between recreational skiers, female and male junior and senior elite cross-country skiers.The experiments showed that during a time period of 30 minutes of rolling on a treadmill (warm-up), μR decreased significantly (p<0.05) to about 60-65 % and 70-75 % of its initial value for freestyle and classical roller skis respectively. Also, there was a significant influence of normal force on μR, while different velocities and inclinations of the treadmill only resulted in small changes in μR.The study of the influence on physiological variables of a ~50 % change in μR showed that during submaximal steady rate exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non-significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a change in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non-significant or small.The study of classical style roller skis μS showed values that were five to eight times more than the values of μS reported from on-snow skiing with grip-waxed cross-country skis.The subsequent physiological and biomechanical experiments with different μS showed a significantly lower skiing economy (~14 % higher v̇O2), higher heart rate, lower propulsive forces coming from the legs and shorter time to exhaustion (~30 %) when using a different type of roller ski with a μS similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a (similar) higher μS.The part of the thesis which focused on skiing economy and efficiency as a function of skill, age and gender, showed that the elite cross-country skiers had better skiing economy and higher gross efficiency (5-18 %) compared with the recreational skiers, and the senior elite had better economy and higher efficiency (4-5 %) than their junior counterparts, while no differences could be found between the genders.

  • 4.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Ainegren, Mats
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    The rolling resistances of roller skis and their effects on human performance during treadmill roller skiing2010Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical performance in a laboratory environment using classical and freestyle techniques on roller skis. For elite athletes the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance coefficient, µR, in order to allow correct comparisons between the results, as well as providing the opportunity to study work economy between different athletes, test occasions and core techniques.

    Thus, one of the aims of this thesis was to evaluate how roller skis’ µR is related to warm-up, mass, velocity and inclination of the treadmill. It was also necessary to investigate the methodological variability of the rolling resistance measurement system, RRMS, specially produced for the experiments, with a reproducibility study in order to indicate the validity and reliability of the results.

    The aim was also to study physiological responses to different µR during roller skiing with freestyle and classical roller skis and techniques on the treadmill as a case in which all measurements were carried out in stationary and comparable conditions.

    Finally, the aim was also to investigate the work economy of amateurs and female and male junior and senior cross-country skiers during treadmill roller skiing, i.e. as a function of skill, age and gender, including whether differences in body mass causes significant differences in external power per kg due to differences in the roller skis’ µR.

    The experiments showed that during a warm-up period of 30 minutes, µR decreased to about 60-65% and 70-75% of its initial value for freestyle and classical roller skis respectively. For another 30 minutes of rolling no significant change was found. Simultaneous measurements of roller ski temperature and mR showed that stabilized mR corresponds to a certain running temperature for a given normal force on the roller ski. The study of the influence on mR of normal force, velocity and inclination produced a significant influence of normal force on mR, while different velocities and inclinations of the treadmill only resulted in small changes in mR. The reproducibility study of the RRMS showed no significant differences between paired measurements with either classical or the freestyle roller skis.

    The study of the effects on physiological variables of ~50% change in µR,showed that during submaximal steady state exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a significantly changed maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non significant or small.

    The final part of the thesis, which focused on work economy, found no significant difference between the four groups of elite competitors, i.e. between the two genders and between the junior and senior elite athletes. It was only the male amateurs who significantly differed among the five studied groups. The study also showed that the external power per kg was significantly different between the two genders due to differences in body mass and mR, i.e. the lighter female testing groups were roller skiing with a relatively heavier rolling resistance coefficient compared to the heavier testing groups of male participants.

  • 5.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Ainegren, Mats
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Carlsson, Peter
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Tinnsten, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Roller ski rolling resistance and its effects on elite athletes’ performance2009In: Sports Engineering, ISSN 1369-7072, E-ISSN 1460-2687, Vol. 11, no 3, 143-157 p.Article in journal (Refereed)
    Abstract [en]

    Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical fitness in a laboratory environment whilst performing classical and freestyle (skating) techniques on roller skis. For elite athletes, the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance in order to allow the correct comparison between the results of different test occasions. In this study, the roller skis’ rolling resistance was measured on the ski-treadmill’s surface using a roller ski rolling resistance measurement system specially produced for this purpose. The study investigated the influence of significant changes in rolling resistance on physiological variables. The results showed that during submaximal exercise, power, oxygen uptake, heart rate and blood lactate were significantly changed by different rolling resistances, while there were no significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed by different rolling resistances and this occurred without significant changes in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion were insignificant or small.

     

  • 6.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Ainegren, Mats
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Carlsson, Peter
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Tinnsten, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Roller ski rolling resistance and its effects on elite athletes’ performance2008In: ENGINEERING OF SPORT 7, VOL 2, 2008, Vol. 11, no 3, 393-400 p.Conference paper (Refereed)
    Abstract [en]

    Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical fitness in a laboratory environment whilst performing classical and freestyle (skating) techniques on roller skis. For elite athletes the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance in order to allow the correct comparison between the results of different test occasions. In this study the roller skis’ rolling resistance has been measured using equipment on the ski-treadmill. The study investigates the influence of significant changes in rolling resistance on physiological variables. The results show that during submaximal exercise, heart rate, blood lactate, power and oxygen uptake are significantly changed by different rolling resistances, while there are no significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests show that time to exhaustion is significantly changed by different rolling resistances and this occurred without significant changes in maximal oxygen uptake and heart rate, and the influence on maximal power and ratings of perceived exertion were insignificant or small.

  • 7.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Ainegren, Mats
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Carlsson, Peter
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Tinnsten, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Rolling resistance for treadmill roller skiing2008In: Sports Engineering, ISSN 1369-7072, E-ISSN 1460-2687, Vol. 11, no 1, 23-29 p.Article in journal (Refereed)
    Abstract [en]

    Modern treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical performance under laboratory conditions using classical and freestyle techniques on roller skis. The differences in performance between tests are quite small for elite athletes, and it is therefore of great importance to control the rolling resistance of the roller skis. Otherwise different physiological tests cannot be accurately compared.

    This study shows that during a warm-up period of  30 minutes the coefficient of rolling resistance (µR) decreases to about 60-65% and 70-75% of its initial value for freestyle and classical roller skis respectively.

    Simultaneous measurements of temperature and µR shows that stabilized rolling resistance corresponds to a certain running temperature for a given normal force on the roller ski.

    Tests were also performed on the influence on µR of normal force, velocity and inclination. Normal forces produced significant influence on µR , while different velocities and inclinations of the treadmill only resulted in small changes in µR.

  • 8.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Ainegren, Mats
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Carlsson, Peter
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Tinnsten, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Laaksonen, Marko
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Work economy of amateur and elite cross-country skiers during treadmill roller skiing2009In: 4th Asia Pacific Congress on Sports Technology, APCST2009, 2009Conference paper (Refereed)
    Abstract [en]

    This study focused on the work economy of cross-country skiers during treadmill roller skiing in the perspectives; skill, age and gender. The study was investigating the external power output from elevating the transported mass against gravity and overcoming the roller skis rolling resistance, and the internal power from measured oxygen uptake and energy consumption. The roller skis rolling resistance was measured with a fixture on the ski-treadmill and the results showed a significant correlation between normal force and rolling resistance. The results also showed that it was only the amateur skiers who significantly differed in work economy among the five studied groups.

  • 9.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Carlsson, Peter
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Laaksonen, Marko S.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Tinnsten, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    The influence of grip on oxygen consumption and leg forces when using classical style roller skis2014In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 24, no 2, 301-310 p.Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to investigate the influence of classical style roller skis' grip (static friction coefficients, μ S) on cross-country skiers' oxygen consumption and leg forces during treadmill roller skiing, when using the diagonal stride and kick double poling techniques. The study used ratcheted wheel roller skis from the open market and a uniquely designed roller ski with an adjustable camber and grip function. The results showed significantly (P≤0.05) higher oxygen consumption (∼14%), heart rate (∼7%), and lower propulsive forces from the legs during submaximal exercise and a shorter time to exhaustion (∼30%) in incremental maximal tests when using roller skis with a μ S similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a similar, higher μ S. Thus, we concluded that oxygen consumption (skiing economy), propulsive leg forces, and performance time are highly changed for the worse when using roller skis with a lower μ S, such as for on-snow skiing with grip-waxed cross-country skis, in comparison to ratcheted wheel roller skis with several times higher μ S.

  • 10.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Carlsson, Peter
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Tinnsten, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    An experimental study to compare the grip of classical style roller skis with on-snow skiing2013In: Sports Engineering, ISSN 1369-7072, E-ISSN 1460-2687, Vol. 16, no 2, 115-122 p.Article in journal (Refereed)
    Abstract [en]

    Cross-country skiers use roller skis for their snow-free training with the aim of imitating skiing on snow. Also, exercise laboratories evaluate the biomechanics and physiology of cross-country skiing using roller skis on a treadmill. The roller skis on the market that are constructed for use in the classical style are equipped with a front and a back wheel, one of which has a ratchet to enable it to grip the surface when diagonal striding and kick double poling (static friction). The aim of this study was to investigate static friction coefficients (μS) of ratcheted wheel roller skis, and compare the results to the μS reported from skiing on snow with grip-waxed cross-country skis. Also, a new type of roller ski with a camber and adjustable grip function was evaluated. The results showed that ratcheted wheel roller skis, on a treadmill rubber mat and on dry and wet asphalt surfaces, reached μS values that were five to eight times greater than the values reported from on-snow skiing with grip-waxed cross-country skis. For the roller skis with a camber and adjustable grip function, the μs could be varied from no grip at all up to the level of the tested ratcheted wheel roller skis.

  • 11.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Carlsson, Peter
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Tinnsten, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Rolling resistance for treadmill roller skiing: Presented at International Congress on Science and Nordic Skiing 2006, June 18-20, 2006, Vuokatti, Finland2006Conference paper (Other academic)
  • 12.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Carlsson, Peter
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Tinnsten, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Laaksonen, Marko S.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Skiing economy and efficiency in recreational and elite cross-country skiers2013In: Journal of Strength and Conditioning Research, ISSN 1064-8011, Vol. 27, no 5, 1239-1252 p.Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to investigate and compare skiing economy and gross efficiency in cross-country skiers of different performance levels, ages and genders; male recreational skiers and elite senior and junior cross-country skiers of both genders. The skiers performed tests involving roller skiing on a treadmill using the gear 3 and diagonal stride techniques. The elite crosscountry skiers were found to have better skiing economy and higher gross efficiency (5-18%) compared with the recreational skiers (p < 0.05) and the senior elite had better economy and higher efficiency (4-5%) than their junior counterparts (p < 0.05), whereas no differences could be found between the genders. Also, large ranges in economy and gross efficiency were found in all groups. It was concluded that, in addition to v̇O2peak, skiing economy and gross efficiency have a great influence on the differences in performance times between recreational and junior and senior elite cross-country skiers, as well as between individual skiers within the different categories. Thus, we recommend crosscountry skiers at all performance levels to test not only v̇O2peak, but also skiing economy and efficiency.

  • 13.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Rännar, Lars-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Carlsson, Peter
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Tinnsten, Mats
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    The multifunctional roller ski2013In: Science and Nordic Skiing II / [ed] Hakkarainen A, Linnamo V, Lindinger S, University of Salzburg, University of Jyväskylä , 2013, 253-261 p.Chapter in book (Refereed)
  • 14. Alkner, B.A
    et al.
    Berg, H.E
    Kozlovskaya, I
    Sayenko, D
    Tesch, P.A
    Effects of strength training, using a gravity-independent exercise system, performed during 110 days of simulated space station confinement2003In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 90, no 1-2, 44-49 p.Article in journal (Refereed)
  • 15. Alkner, B.A
    et al.
    Tesch, P.A
    Berg, H.E
    Quadriceps EMG/force relationship in knee extension and leg press2000In: Journal of Gravitational Physiology, Vol. 32, no 2, 459-463 p.Article in journal (Refereed)
  • 16. Alkner, Björn A
    et al.
    Tesch, Per A
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Knee extensor and plantar flexor muscle size and function following 90 days of bed rest with or without resistance exercise.2004In: European Journal of Applied Physiology, ISSN 1439-6319, Vol. 93, no 3, 294-305 p.Article in journal (Refereed)
    Abstract [en]

    Skeletal muscle atrophy and strength loss induced by short-term simulated spaceflight are offset or attenuated by resistance exercise (RE). This study compared the effects of plantar flexor and knee extensor RE on muscle size and function in 17 healthy men (aged 26–41years) subjected to 90 days 6 head-down-tilt bed rest with (BRE; n=8) or without (BR; n=9) RE. The RE program consisted of coupled maximal concentric and eccentric actions in the supine squat (4 sets of 7 repetitions) and calf press (4·14) every third day employing a gravity-independent flywheel ergometer (FW). Prior to, and following bed rest, muscle volume was assessed using magnetic resonance imaging. Similarly, muscle strength and power and surface lectromyographic (EMG) activity were determined during maximal actions using FW or isokinetic dynamometry. In BR, knee extensor and plantar flexor muscle volume decreased (P<0.05) 18% and 29%, respectively. Torque or force and power decreased (P<0.05) 31–60% (knee extension) and 37–56% (plantar flexion) while knee extensor and plantar flexor EMG activity decreased 31–38% and 28–35%, respectively following BR. Muscle atrophy in BRE was prevented (P>0.05; knee extensors) or attenuated ()15%; plantar flexors). BRE maintained task-specific force, power and EMG activity. The decrease in non-task-specific torque was less (P<0.05) than in BR. The present data imply that the triceps surae and quadriceps muscles show different responsiveness to long-term bed rest with or without resistance exercise. The results also suggest that designing in-flight resistance exercise protocols for space travellers is complex and must extend beyond preserving

  • 17. Alkner, Björn
    et al.
    Tesch, Per A
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Efficacy of a gravity-independent resistance exercise device as a countermeasure to muscle atrophy during 29-day bed rest.2004In: Acta Physioloogica Scandinavica, ISSN 0001-6772, Vol. 181, no 3, 345-357 p.Article in journal (Refereed)
    Abstract [en]

    This study determined changes in knee extensor and plantar flexor muscle volume during 29 days of bed rest with or without resistance exercise using a gravity-independent flywheel ergometer. METHODS: Seventeen men (26-41 years) were subjected to 29 days of bed rest with (n = 8) or without (n = 9) resistance exercise; Supine Squat (SS) and Calf Press (CP) performed every third day. Quadriceps and triceps surae muscle volume was determined before and after bed rest and force and power were measured during training. Prior to these interventions, reproducibility of this device for training and testing was assessed in 23 subjects who performed bilateral maximal concentric, eccentric and isometric (MVC) knee extensions and plantar flexions over repeated sessions with simultaneous measurements of force, power and electromyographic (EMG) activity. RESULTS: Quadriceps and triceps surae muscle volume decreased (P < 0.05) 10 and 16%, respectively, after 29 days bed rest. Exercise maintained quadriceps volume and mitigated triceps surae atrophy. Thus, either muscle showed different response across subject groups (P < 0.05). Force and power output during training were either maintained (P > 0.05) or increased (P < 0.05). EMG amplitude in the training mode was similar (SS; P > 0.05) or greater (CP; P < 0.05) compared with that elicited during MVC. Peak force and power test-retest coefficient of variation (CV) ranged 5-6% and 7-8% for SS and CP, respectively. CONCLUSION: The present data suggest that this resistance exercise paradigm counteracts quadriceps and abates the more substantial triceps surae muscle atrophy in bedridden subjects, and therefore should be an important asset to space travellers.

  • 18.
    Alricsson, Marie
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Dans ger bättre resultat i skidspåren? 1999Other (Other (popular scientific, debate etc.))
  • 19.
    Alricsson, Marie
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Dans ger friskare ryggar hos längdåkare2004In: Glid, ISSN 1652-2737, no 4Article in journal (Other (popular scientific, debate etc.))
  • 20.
    Alricsson, Marie
    et al.
    Linnaeus University.
    Björklund, Glenn
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Swedish Sports Confederat.
    Ekström, A.
    Linnaeus University.
    Ostenberg, A. Hafsteinsson
    Linnaeus University.
    Introducing Tabata intervals and stability exercises in school children by a school-based study2016In: European Journal of Public Health, ISSN 1101-1262, E-ISSN 1464-360X, Vol. 26, 417-417 p.Article in journal (Refereed)
  • 21.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Domalewski, D
    Physical activity, health and prevalence of overweight and musculoskeletal complaints in young women2008In: Exercise and Women's Health Research, New York: Nova Science Publishers, Inc., 2008, 143-155 p.Chapter in book (Other academic)
  • 22.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Harms-Ringdahl, Karin
    Eriksson, K
    Werner, Suzanne
    The effect of dance training on joint mobility, muscle flexibility, speed and agility in young cross-country skiers,: a prospective controlled intervention study.2003In: Scandinavian Journal of Medicine & Science in Sports, ISSN 0905-7188, Vol. 13, no 4, 237-243 p.Article in journal (Refereed)
  • 23.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Harms-Ringdahl, Karin
    Schüldt, Kristina
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Ekholm, Jan
    linder, Jürgen
    Mobility, muscular strength and endurance in the cervical spine in Swedish air force pilots2001In: Aviation, Space, and Environmental Medicine, ISSN 0095-6562, Vol. 72, no 4, 336-342 p.Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Muscle strength, endurance and range of movement of the cervical spine in a group of Swedish Air Force jet pilots (AF) and in a reference group of conscripts doing their military service (RG) were compared. METHODS: We tested 30 (AF) 24-42 yr and 33 (RG) 19-22 yr. A questionnaire was used to document complaints. Maximum voluntary isometric muscle strength of the flexor and extensor muscles of the cervical spine and sub-maximum isometric endurance in the flexor and extensor muscles were measured. RESULTS: Eleven AF (37%) and four RG (12%) had experienced discomfort in the neck within the previous year. The pilots' flexor and extensor muscle strength (47 Nm and 65 Nm) was superior to that of the conscripts (36 Nm and 59 Nm) (p = 0.0001, p = < 0.05, respectively). However, the RG group had greater isometric endurance in the flexor muscles than AF (p = < 0.05) and greater neck rotation (p = <0.005). There was no difference between the two groups in the other variables. CONCLUSION: Differences between the groups with regard to muscle strength and endurance might depend on variations in work-related physical muscle strain, and/or differences in fiber composition in the muscles, which might be reflected by pilot selection procedures.

  • 24.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Harms-Ringdahl, Karin
    Werner, Suzanne
    Reliability of sports related functional tests with emphasis on speed and agility in young athletes.2001In: Scandinavian Journal of Medicine & Science in Sports, ISSN 0905-7188, Vol. 11, no 4, 229-232 p.Article in journal (Refereed)
    Abstract [en]

    The aim of the present investigation was to test the reliability of two sports related functional tests, a speed test (slalom-test) and an agility test (hurdle-test). Eleven athletes aged 11 years (8 boys, 3 girls) participated voluntarily in the study. All subjects completed four different test sessions for both the slalom-test and the hurdle-test using six standard track hurdles placed at 2-m intervals along a 12-m length of track. There were no significant differences between testing sessions for either the slalom-test (P=0.99) or the hurdle-test (P=0.96), showing no systematic variation between test times. The intraclass correlation coefficients were 0.96 and 0.90 respectively, indicating a good reliability. We conclude that the slalom-test and the hurdle-test are reliable sports related functional tests for measuring speed and agility in groups of young athletic individuals.

  • 25.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Landstad, Bodil
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Physical activity, self-related health and complaints in adolescents2007In: Adolescent behaviour research: International perspectives, New York: Nova Science Publishers, Inc., 2007, , 179 p.119-128 p.Chapter in book (Other academic)
  • 26.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Werner, Suzanne
    Dansträning för längdskidåkare: får jag lov, Per Elofsson?2002In: Svensk idrottsforskning, ISSN 1103-4629, Vol. 11, no 4, 77-79 p.Article in journal (Other scientific)
  • 27.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Werner, Suzanne
    Dansträning ger längdskidåkare mindre ryggbesvär. 2004In: Svensk Idrottsmedicin, ISSN 1103-7652, Vol. 23, no 2, 23-26 p.Article in journal (Other scientific)
  • 28.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Werner, Suzanne
    Hälsa, aktivitetsgrad och besvärsfrekvens bland längdskidåkare vid Sveriges riksskidgymnasier.2004In: Svensk idrottsforskning, ISSN 1103-4629, Vol. 13, no 1, 22-24 p.Article in journal (Other scientific)
  • 29.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Werner, Suzanne
    Reliability tests of joint motion and muscle flexibility of the hip. 2002In: Nordisk fysioterapi, ISSN 1402-3024, Vol. 6, no 3, 119-124 p.Article in journal (Refereed)
  • 30.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Section of Sports Medicine, Department of Surgical Sciences, Karolinska Institute, Stockholm.
    Werner, Suzanne
    Section of Sports Medicine, Department of Surgical Sciences, Karolinska Institute, Stockholm; Capio Artro Clinic, S:t Görans Hospital, Stockholm.
    Self-reported health, physical activity and prevalence of complaints in elite cross-country skiers and matched controls2005In: Journal of Sports Medicine and Physical Fitness, ISSN 0022-4707, E-ISSN 1827-1928, Vol. 45, no 4, 547-552 p.Article in journal (Refereed)
    Abstract [en]

    Aim. The purpose of this study was to compare physical health, physical activity and location for possible symptoms in high school students with cross-country skiers of the same age from ski high schools. Another aim was to study back pain with regards to influence on skiing.Methods. The subjects studied were: 92% (n=120) of all Swedish cross-country skiers at ski high schools and 68% (n=993) of regular high school students from the North part of Sweden answered a reliable questionnaire (r=1) with regards to health, physical activity and location of possible symptoms/injuries during the last 3 months. Furthermore, the skiers answered questions on possible ski related back pain.Results. All skiers were active also in other sports compared with 26% of the controls and at considerably higher levels of physical effort than the controls; 92% of the skiers and 76% of the controls described themselves as healthy, meaning "very good" or "good" (P=0.0001); 55% of the skiers and 64% of the controls reported recent symptoms (P=0.06); 47% of the skiers reported previous or present complaints of back pain, mainly low back pain, which could be relieved by changing body position from a flexed to a more extended one while skiing, and 77% reported their back pain to disappear during rest.Conclusion. These results show the need for encouraging regular high school students to participate in sport. It also shows the importance of introducing preventative strategies regarding back pain to long-distance cross-country skiers, who are exposed to a prolonged flexed position of their back.

  • 31.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Werner, Suzanne
    The effect of pre-season dance training on physical indices and back pain in elite cross-country skiers: a prospective controlled intervention study2004In: British journal of sports medicine, ISSN 0306-3674, Vol. 38, no 2, 148-153 p.Article in journal (Refereed)
  • 32.
    Alricsson, Marie
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Werner, Suzanne
    Karolinska Institutet, Stockholm.
    Young elite cross-country skiers and low back pain: A 5-year study2006In: Physical Therapy in Sport, ISSN 1466-853X, E-ISSN 1873-1600, Vol. 7, no 4, 181-184 p.Article in journal (Refereed)
    Abstract [en]

    Objectives To evaluate possible changes in spinal curvature over a period of 5 years of an elite cross-country skiing squad, and to study whether there are any differences in this respect between individuals who report low back pain and those how do not. Participants Fifteen young cross-country skiers (M age=13.6±0.9) participated voluntarily throughout the entire study period. Main outcome measures Debrunner's kyphometer was used for measuring the difference between thoracic kyphosis and lumbar lordosis of the spine. All subjects also answered a questionnaire including questions about ski-related low back pain, the amount of ski training, and participation in other sports. Results The results at the end of the 5-year period comprise data from 15 skiers (M age=18.5±0.9 years). The relationship between thoracic kyphosis and lumbar lordosis increased from 3.5° to 13.1°, respectively (p=0.0001). Of the 15 elite cross-country skiers, seven reported low back pain at the 5-year examination. At the 5-year follow-up, skiers with low back pain showed significantly higher relationship between thoracic kyphosis and lumbar lordosis than did those skiers without low back pain, 18.2° and 10.5°, respectively (p=0.035). Of the eight elite cross-country skiers without low back pain, seven were also involved in other sports (p=0.005). Conclusions Based on these findings, our advice is that adolescent cross-country skiers also should participate in other physical activities besides cross-country skiing.

  • 33.
    Andersson, Erik
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Pellegrini, Barbara
    CeRiSM, Research Center for Sport, Mountain and Health, Rovereto, Italy.
    Sandbakk, Öyvind
    Centre for Elite Sports Research, Norwegian University of Science and Technology, Trondheim, Norway .
    Stöggl, Thomas
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Department of Sport Science and Kinesiology, University of Salzburg, Salzburg, Austria .
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Swedish Olympic Committee, Stockholm, Sweden.
    The effects of skiing velocity on mechanical aspects of diagonal cross-country skiing2014In: Sports Biomechanics, ISSN 1476-3141, E-ISSN 1752-6116, Vol. 13, no 3, 267-284 p.Article in journal (Refereed)
    Abstract [en]

    Cycle and force characteristics were examined in 11 elite male cross-country skiers using the diagonal stride technique while skiing uphill (7.5 degrees) on snow at moderate (3.5 +/- 0.3m/s), high (4.5 +/- 0.4m/s), and maximal (5.6 +/- 0.6m/s) velocities. Video analysis (50Hz) was combined with plantar (leg) force (100Hz), pole force (1,500Hz), and photocell measurements. Both cycle rate and cycle length increased from moderate to high velocity, while cycle rate increased and cycle length decreased at maximal compared to high velocity. The kick time decreased 26% from moderate to maximal velocity, reaching 0.14s at maximal. The relative kick and gliding times were only altered at maximal velocity, where these were longer and shorter, respectively. The rate of force development increased with higher velocity. At maximal velocity, sprint-specialists were 14% faster than distance-specialists due to greater cycle rate, peak leg force, and rate of leg force development. In conclusion, large peak leg forces were applied rapidly across all velocities and the shorter relative gliding and longer relative kick phases at maximal velocity allow maintenance of kick duration for force generation. These results emphasise the importance of rapid leg force generation in diagonal skiing.

  • 34.
    Andersson, Erik
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Stöggl, Thomas
    University of Salzburg.
    Pellegrini, Barbara
    University of Verona.
    Sandbakk, Oyvind
    NTNU, Trondheim, Norge.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Biomechanical comparison of different uphill techniques in the classical style cross-country skiing2010In: Proceedings for the fifth international conference on Science and Skiing / [ed] Erich Mueller, Salzburg, Austria: Meyer & Meyer Sport, 2010, 46- p.Conference paper (Refereed)
  • 35.
    Andersson, Erik
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Supej, Matej
    University of Ljubljana, Ljubljana, Slovenien.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Analysis of a sprint qualification round in cross-country skiing using a differential global navigation system2009In: Proceedings of the 14th Annual Congress of European College of Sports Science / [ed] Loland, S., Bø, K., Fasting, K., Hallén, J., Ommundsen, Y., Roberts, G., Tsolakidis, E., Oslo: Gamlebyen Grafiske AS , 2009Conference paper (Refereed)
  • 36.
    Andersson, Erik
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Supej, Matej
    Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia.
    Sandbakk, Oyvind
    Human Movement Science Programme, Norwegian University of Science and Technology, Trondheim, Norway.
    Sperlich, Billy
    Institute of Training Science and Sport Informatics, German Sport University Cologne, Germany .
    Stöggl, Thomas
    Department of Sport Science and Kinesiology, University of Salzburg, Salzburg, Austria.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Analysis of sprint cross-country skiing using a differential global navigation satellite system2010In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 110, no 3, 585-595 p.Article in journal (Refereed)
    Abstract [en]

    The purpose was to examine skiing velocities, gear choice (G2-7) and cycle rates during a skating sprint time trial (STT) and their relationships to performance, as well as to examine relationships between aerobic power, body composition and maximal skiing velocity versus STT performance. Nine male elite cross-country skiers performed three tests on snow: (1) Maximum velocity test (Vmax) performed using G3 skating, (2) Vmax test performed using double poling (DP) technique and (3) a STT over 1,425 m. Additional measurements of VO2max during roller skiing and body composition using iDXA were made. Differential global navigation satellite system data were used for position and velocity and synchronized with video during STT. The STT encompassed a large velocity range (2.9-12.9 m s-1) and multiple transitions (21-34) between skiing gears. Skiing velocity in the uphill sections was related to gear selection between G2 and G3. STT performance was most strongly correlated to uphill time (r = 0.92, P < 0.05), the percentage use of G2 (r = -0.72, P < 0.05), and DP Vmax (r = -0.71, P < 0.05). The velocity decrease in the uphills from lap 1 to lap 2 was correlated with VO2max (r = -0.78, P < 0.05). Vmax in DP and G3 were related to percent of racing time using G3. In conclusion, the sprint skiing performance was mainly related to uphill performance, greater use of the G3 technique, and higher DP and G3 maximum velocities. Additionally, VO2max was related to the ability to maintain racing velocity in the uphills and lean body mass was related to starting velocity and DP maximal speed.

  • 37.
    Andersson, Erik
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Willis, Sarah J.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Ørtenblad, Niels
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Energy System Contributions And Determinants Of Performance In Classical Sprint Cross-Country Skiing2014In: Proceedings for the 19th ECCS in Amsterdam, The Netherlands, 2014Conference paper (Refereed)
  • 38. Andersson, J
    et al.
    Biasoletto-Tjellström, G
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Reduced pulmonary oxygen uptake during apnea in resting humans: European Underwater and Baromedical Society (EUBS) meeting Copenhagen2003Conference paper (Other academic)
  • 39. Andersson, Johan
    et al.
    Linér, Mats
    Fredsted, Anne
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Cardiovascular and respiratory responses to apneas with and without face immersion in exercising humans2004In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 96, no 3, 1005-1010 p.Article in journal (Refereed)
    Abstract [en]

    The effect of the diving response on alveolar gas exchange was investigated in 15 subjects. During steady-state exercise (80 W) on a cycle ergometer, the subjects performed 40-s apneas in air and 40-s apneas with face immersion in cold (10degreesC) water. Heart rate decreased and blood pressure increased during apneas, and the responses were augmented by face immersion. Oxygen uptake from the lungs decreased during apnea in air (-22% compared with eupneic control) and was further reduced during apnea with face immersion (-25% compared with eupneic control). The plasma lactate concentration increased from control (11%) after apnea in air and even more after apnea with face immersion (20%), suggesting an increased anaerobic metabolism during apneas. The lung oxygen store was depleted more slowly during apnea with face immersion because of the augmented diving response, probably including a decrease in cardiac output. Venous oxygen stores were probably reduced by the cardiovascular responses. The turnover times of these gas stores would have been prolonged, reducing their effect on the oxygen uptake in the lungs. Thus the human diving response has an oxygen-conserving effect.

  • 40. Andersson, Johan P A
    et al.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Repeated apneas do not affect the hypercapnic ventilatory response in the short term2009In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 105, no 4, 569-74 p.Article in journal (Refereed)
    Abstract [en]

    Long-term training of breath-hold diving reduces the hypercapnic ventilatory response (HCVR), an index of the CO(2) sensitivity. The aim of the present study was to elucidate whether also short-term apnea training (repeating apneas with short intervals) reduces the HCVR, thereby being one contributing factor explaining the progressively increasing breath-holding time (BHT) with repetition of apneas. Fourteen healthy volunteers performed a series of five maximal-duration apneas with face immersion and two measurements of the HCVR, using the Read rebreathing method. The BHT increased by 43% during the series of apneas (P < 0.001). However, the slope of the HCVR test was not affected by the series of apneas, being 2.52 (SD 1.27) and 2.24 (SD 1.14) l min(-1) mmHg(-1) in the control test and in the test performed within 2 min after the last apnea of the series, respectively (NS). Thus, a change in the HCVR cannot explain the observed short-term training effect on BHT.

  • 41.
    Andersson, Johan P.A.
    et al.
    Lunds universitet.
    Biasoletto-Tjellströma, Gustaf
    Schagatay, Erika K.A
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Pulmonary gas exchange is reduced by the cardiovascular diving response in resting humans2008In: Respiratory Physiology & Neurobiology, ISSN 1569-9048, Vol. 160, no 3, 320-324 p.Article in journal (Refereed)
    Abstract [en]

    The diving response reduces the pulmonary O2 uptake in exercising humans, but it has been debated whether this effect is present at rest. Therefore, respiratory and cardiovascular responses were recorded in 16 resting subjects, performing apnea in air and apnea with face immersion in cold water (10 ◦C). Duration of apneas were predetermined to be identical in both conditions (average: 145 s) and based on individual maximal capacity (average: 184 s). Compared to apnea in air, an augmented diving response was elicited by apnea with face immersion. The O2 uptake from the lungs was reduced compared to the resting eupneic control (4.6 ml min−1 kg−1), during apnea in air (3.6 ml min−1 kg−1) and even more so during apnea with face immersion (3.4 ml min−1 kg -1). We conclude that the cardiovascular djustments of the diving response reduces pulmonary gas exchange in resting humans, allowing longer apneas by preserving the lungs’ O2 store for use by vital organs.

  • 42.
    Andersson, Johan P.A.
    et al.
    Department of Animal Physiology, Lund University.
    Linér, Mats H.
    Lund University Hospital.
    Rünow, Elisabeth
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Diving response and arterial oxygen saturation during apnea and exercise in breath-hold divers2002In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 93, no 3, 882-886 p.Article in journal (Refereed)
    Abstract [en]

    This study addressed the effects of apnea in air and apnea with face immersion in cold water (10°C) on the diving response and arterial oxygen saturation during dynamic exercise. Eight trained breath-hold divers performed steady-state exercise on a cycle ergometer at 100 W. During exercise, each subject performed 30-s apneas in air and 30-s apneas with face immersion. The heart rate and arterial oxygen saturation decreased and blood pressure increased during the apneas. Compared with apneas in air, apneas with face immersion augmented the heart rate reduction from 21 to 33% (P < 0.001) and the blood pressure increase from 34 to 42% (P < 0.05). The reduction in arterial oxygen saturation from eupneic control was 6.8% during apneas in air and 5.2% during apneas with face immersion (P < 0.05). The results indicate that augmentation of the diving response slows down the depletion of the lung oxygen store, possibly associated with a larger reduction in peripheral venous oxygen stores and increased anaerobiosis. This mechanism delays the fall in alveolar and arterial Po2 and, thereby, the development of hypoxia in vital organs. Accordingly, we conclude that the human diving response has an oxygen-conserving effect during exercise.

  • 43. Andersson, Johan
    et al.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Arterial oxygen desaturation during apnea in humans.1998In: Undersea & Hyperbaric Medicine, ISSN 1066-2936, Vol. 25, no 1, 21-25 p.Article in journal (Refereed)
    Abstract [en]

    We studied the effect of the human diving response, defined as bradycardia and reduced peripheral blood flow, on arterial hemoglobin desaturation. We induced a diving response of different magnitudes by using apnea in air and apnea with face immersion. Each of21 subjects performed five apneas in air and five apneas with face immersion in 10°C water. Periods of apnea in both conditions were of the same duration in any individual subject (average: 126.4 s) and the order of air and water was equally distributed among subjects. Heart rate, skin capillary blood flow, arterial blood pressure, arterial hemoglobin oxygen saturation during apneas, and end-tidal fractions of CO2 after apneas were recorded with non-invasive methods. The bradycardia and capillary blood flow reduction during apnea in air (7.8 and 37.7% change from control, respectively) were significantly potentiated by face immersion (13.6 and 55.9%, respectively). Arterial hemoglobin desaturated more during apnea in air (2.7%) compared to during apnea with face immersion (1.4%). We conclude that the potentiation of the human diving response with face immersion in cold water leads to a smaller decrease in arterial hemoglobin saturation, which may reflect an oxygen-conserving effect

  • 44. Andersson, Johan
    et al.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Diving response and apneic time in humans. 1998In: Undersea & Hyperbaric Medicine, ISSN 1066-2936, Vol. 25, no 1, 13-19 p.Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to compare apneic time with the human diving response, defined as heart rate (HR) reduction and reduced skin blood flow, in groups with varying degrees of breath-hold diving experience. Apneic time and HR reduction at apneas in air and apneas with face immersion in cold water were thus recorded in nine groups. Skin capillary blood flow was recorded in six of the groups. All subjects received the same information on maximizing apneic duration, and no information about their progress during the apneas. The longest apneas and the most pronounced cardiovascular adjustments were found in the young, trained divers. It was found that apneic time was significantly correlated to HR reduction among the nine groups (r = 0.94, P < 0.001), and to skin capillary blood flow reduction among the six groups where the parameter was measured (r = 0.82, P < 0.05). The correlation between HR reduction and skin capillary blood flow reduction was also significant (r = 0.85, P < 0.05). When the difference in HR reduction and apneic time between apneas in air and apneas with face immersion were compared in the nine groups, it was found that all groups reacted with a more pronounced HR reduction during apneas with face immersion. All groups without prior breath-hold diving experience were found to perform shorter apneas with face immersion than apneas in air, or apneas of the same duration in both conditions, which has been reported in other studies. However, in all groups with diving experience, the apneic time was prolonged during apneas with face immersion. The results of this study suggest an oxygen-conserving effect of the diving response in trained apneic divers

  • 45. Andersson, Johan
    et al.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Effects of lung volume and involuntary breathing movements on the human diving response1997In: European Journal of Applied Physiology, ISSN 1439-6319, Vol. 77, no 1/2, 19-24 p.Article in journal (Refereed)
    Abstract [en]

    The effects of lung volume and involuntary breathing movements on the human diving response were studied in 17 breath-hold divers. Each subject performed maximal effort apnoeas and simulated dives by apnoea and cold water face immersion, at lung volumes of 60%, 85%, and 100% of prone vital capacity (VC). Time of apnoea, blood pressure, heart rate, skin capillary blood flow, and fractions of end-expiratory CO 2 and O 2 were measured. The length of the simulated dives was the shortest at 60% of VC, probably because at this level the build up of alveolar CO 2 was fastest. Apnoeas with face immersion at 100% of VC gave a marked drop in arterial pressure during the initial 20?s, probably due to high intrathoracic pressure mechanically reducing venous return. The diving response was most pronounced at 60% of VC. We concluded that at the two larger lung volumes both mechanical factors and input from pulmonary stretch receptors influenced the bradycardia and vasoconstriction, resulting in a non-linear relationship between the breath-hold lung volume and magnitude of the diving response in the near-VC range. Furthermore, the involuntary breathing movements that appeared during the struggle phase of the apnoeas were too small to affect the diving response

  • 46. Andersson, Johan
    et al.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Gislén, Anna
    Holm, Boris
    Cardiovascular responses to cold water immersions of the forearm and face, and their relationship to apnoea2000In: European Journal of Applied Physiology, ISSN 1439-6319, Vol. 83, no 6, 566-572 p.Article in journal (Refereed)
    Abstract [en]

    Apnoea as well as cold stimulation of the face or the extremities elicits marked cardiovascular reflexes in humans. The purpose of this study was to investigate whether forearm immersion in cold water has any effect on the cardiovascular responses to face immersion and apnoea. We recorded cardiovascular responses to cold-water immersions of the forearm and face in 19 (part I) and 23 subjects (part II). The experimental protocol was divided in two parts, each part containing four tests: I1, forearm immersion during eupnoea; I2, face immersion during eupnoea; I3, forearm and face immersion during eupnoea; I4, face immersion during apnoea; II1, apnoea without immersion; II2, forearm immersion during apnoea; II3, face immersion during apnoea; and II4, forearm and face immersion during apnoea. The water temperature was 9–11 °C. Cold-water immersion of either the forearm or face was enough to elicit the most pronounced thermoregulatory vasoconstriction during both eupnoea and apnoea. During eupnoea, heart rate responses to forearm immersion (3% increase) and face immersion (9% decrease) were additive during concurrent stimulation (3% decrease). During apnoea, the heart rate responses were not affected by the forearm immersion. The oxygen-conserving diving response seems to dominate over thermoregulatory responses in the threat of asphyxia. During breathing, however, the diving response serves no purpose and does not set thermoregulatory adjustments aside

  • 47.
    Andersson Nyberg, Robin
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Prestationsjämförelse mellan positionerna back och anfallare på daminnebandyspelare2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 48.
    Anna, Johansson
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Faktorer som motiverar till fysisk aktivitet - en litteraturöversikt.2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 49.
    Appelqvist, Emma
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Fysiska aktivitetens påverkan på hälsorelaterad livskvalitet hos äldre2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 50. Apple, F.S
    et al.
    Tesch, P.A
    CK and LD isozymes in human single muscle fibers in trained athletes1989In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 66, no 6, 2717-2720 p.Article in journal (Refereed)
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