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  • 1. Balsom, Paul
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Sjödin, Bertil
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap. Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    Maximal-Intensity Intermittent Exercise: Effect of Recovery Duration1992Inngår i: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, Vol. 13, nr 7, s. 528-533Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Seven male subjects performed 15 x 40m sprints, on three occasions, with rest periods of either 120 s (R120), 60 s (R60) or 30 s (R30) between each sprint. Sprint times were recorded with four photo cells placed at 0, 15, 30 and 40 m. The performance data indicated that whereas running speed over the last 10 m of each sprint decreased in all three protocols (after 11 sprints in R120, 7 sprints in R60 and 3 sprints in R30), performance during the initial acceleration period from 0-15 m was only affected with the shortest rest periods increasing from (mean +/- SEM) 2.58 +/- .03 (sprint 1) to 2.78 +/- .04 s (spring 15) (p < .05). Post-exercise blood lactate concentration was not significantly different in R120 (12.1 +/- 1.3 mmol.l-1) and R60 (13.9 +/- 1.2 mmol.l-1), but a higher concentration was found in R30 (17.2 +/- .7 mmol.l-1) (p < .05). After 6 sprints there was no significant difference in blood lactate concentration with the different recovery durations, however, there were significant differences in sprint times at this point, suggesting that blood lactate is a poor predictor of performance during this type of exercise. Although the work bouts could be classified primarily as anaerobic exercise, oxygen uptake measured during rest periods increased to 52, 57 and 66% of maximum oxygen uptake in R120, R60 and R30, respectively. Evidence of adenine nucleotide degradation was provided by plasma hypoxanthine and uric acid concentrations elevated post-exercise in all three protocols. Post-exercise uric acid concentration was not significantly affected by recovery duration.(ABSTRACT TRUNCATED AT 250 WORDS)

  • 2. Balsom, Paul
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Sjödin, Bertil
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Physiological responses to maximal intensity intermittent exercise1992Inngår i: European Journal of Applied Physiology and Occupational Physiology, ISSN 0301-5548, E-ISSN 1432-1025, Vol. 65, s. 144-149Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Physiological responses to repeated bouts of short duration maximal-intensity exercise were evaluated. Seven male subjects performed three exercise protocols, on separate days, with either 15 (S15), 30 (S30) or 40 (S40) m sprints repeated every 30 s. Plasma hypoxanthine (HX) and uric acid (UA), and blood lactate concentrations were evaluated pre- and postexercise. Oxygen uptake was measured immediately after the last sprint in each protocol. Sprint times were recorded to analyse changes in performance over the trials. Mean plasma concentrations of HX and UA increased during S30 and S40 (P less than 0.05), HX increasing from 2.9 (SEM 1.0) and 4.1 (SEM 0.9), to 25.4 (SEM 7.8) and 42.7 (SEM 7.5) mumol.l-1, and UA from 372.8 (SEM 19) and 382.8 (SEM 26), to 458.7 (SEM 40) and 534.6 (SEM 37) mumol.l-1, respectively. Postexercise blood lactate concentrations were higher than pretest values in all three protocols (P less than 0.05), increasing to 6.8 (SEM 1.5), 13.9 (SEM 1.7) and 16.8 (SEM 1.1) mmol.l-1 in S15, S30 and S40, respectively. There was no significant difference between oxygen uptake immediately after S30 [3.2 (SEM 0.1) l.min-1] and S40 [3.3 (SEM 0.4) l.min-1], but a lower value [2.6 (SEM 0.1) l.min-1] was found after S15 (P less than 0.05). The time of the last sprint [2.63 (SEM 0.04) s] in S15 was not significantly different from that of the first [2.62 (SEM 0.02) s]. However, in S30 and S40 sprint times increased from 4.46 (SEM 0.04) and 5.61 (SEM 0.07) s (first) to 4.66 (SEM 0.05) and 6.19 (SEM 0.09) s (last), respectively (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS

  • 3. Bergsten, Urban
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Ledarskap: ett nytt kunskapsområde vid GIH2014Inngår i: Från Kungl. Gymnastiska Centralinstitutet till Gymnastik- och idrottshögskolan: en betraktelse av de senaste 25 åren som del av en 200-årig historia / [ed] Suzanne Lundvall, Stockholm: Gymnastik- och idrottshögskolan, GIH , 2014, s. 146-153Kapittel i bok, del av antologi (Annet (populærvitenskap, debatt, mm))
  • 4.
    Bergsten, Urban
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    "Team building" är inte alltid Team building2007Inngår i: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, nr 2, s. 74-79Artikkel i tidsskrift (Annet vitenskapelig)
  • 5. Fridén, Jan
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    Implementation of periodic acid-thiosemicarbazide-silver proteinate staining for ultrastructural assessment of muscle glycogen utilization during exercise1985Inngår i: Cell and Tissue Research, ISSN 0302-766X, E-ISSN 1432-0878, nr 242, s. 229-232Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Distribution of glycogen particles in semithin and ultrathin sections of biopsy samples from human muscles subjected to either short- or long-term running were investigated using PAS and Periodic Acid-ThioSemiCarbazide-Silver Proteinate (PA-TSC-SP) staining methods. Glycogen particles were predominantly found immediately under the sarcolemma or aligned along the myofibrillar I-band. After long-term exhaustive exercise type-1 fibers with a few or no glycogen particles in the core of the fibers were frequently observed. The subsarcolemmal glycogen stores of these "depleted" type-1 fibers were about three times as large as after exhaustive short-time exercise. Another indication of utilization of subsarcolemmal glycogen stores during anaerobic exercise was that many particles displayed a pale, rudimentary shape. This observation suggests fragmental metabolization of glycogen. Thus, depending on type of exercise and type of fiber differential and sequential glycogen utilization patterns can be observed

  • 6. Fridén, Jan
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    Sublethal muscle fibre injuries after high-tension anaerobic exercise1988Inngår i: European Journal of Applied Physiology and Occupational Physiology, ISSN 0301-5548, E-ISSN 1432-1025, nr 57, s. 360-368Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The vastus lateralis muscles of eleven male elite sprinters (17-28 years) were investigated in order to examine the impact of high tension anaerobic muscular work on muscle fibre fine structure. In an attempt to reproduce the training regimen six subjects ran 20 repetitions of 25 s on a treadmill with 2 min 35 s in between, at a speed corresponding to 86% of their personal best 200 m time. PAS-stained sections of biopsies taken approximately 2 h after training generally indicated glycogen depletion in type 1 and type 2B fibres. At the light microscopic level, no signs of inflammation or fibre rupture were observed. However, at the ultrastructural level, frequent abnormalities of the contractile material and the cytoplasmic organelles were detected. Z-band streaming, autophagic vacuoles and abnormal mitochondria were the most conspicuous observations. Control specimens from sprinters who did not perform the acute exercise routine also displayed structural deviations, although to a lesser degree. It is hypothesized that during sprint training the leg musculature is put under great mechanical and metabolic stress which causes the degenerative response reported here.

  • 7. Fridén, Jan
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    Topographical localization of muscle glycogen: an ultrahistochemical study in the human vastus lateralis1989Inngår i: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 135, s. 381-391Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The fine structural pattern of glycogen storage in resting and sprint-exercised human vastus lateralis muscle fibres of different types was analysed using ultrahistochemical methods. Three male subjects (31-36 years) performed 60 consecutive, supramaximal bouts of bicycle exercise, each starting every 1 min and having a duration of 8 s (including approximately 3 s of acceleration). The load was estimated to correspond to 200% of VO2-max. Five other subjects (22-27 years) constituted controls. Ultrathin sections stained with periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) clearly revealed a compartmental distribution of glycogen. Glycogen is stored at five topographically, and probably also functionally, different locations. They are the subsarcolemmal, intermyofibrillar, para-Z-disc, N2-line, and H-zone spaces. During the exercise, glycogen from the N2-line and para-Z-disc locations is preferentially utilized. Serial sections stained with uranyl acetate and lead citrate demonstrated that glycogen stores of the type 2 fibres were more depleted than those of type 1 fibres. The implications of the differential intracellular glycogen storage are discussed

  • 8. Fridén, Jan
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Sjöström, Michael
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    Adaptive Response in Human Skeletal Muscle Subjected to Prolonged Eccentric Training1983Inngår i: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, nr 4, s. 177-183Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The peripheral adaptation process associated with repeating eccentric training over a longer period of time was studied in m. vastus lateralis of eleven healthy males aged 24 +/- 4 years. The maximal dynamic concentric muscle strength was only slightly improved after 8 weeks of training. However, eccentric work capacity was dramatically increased (375%). A maximal eccentric stint immediately after fulfilled 8 weeks of training caused a selective glycogen depletion from the type 28 fibers. An increased number of type 2C fibers was observed. The ultrastructure analysis showed an essentially well-preserved fine structure. Volume density of mitochondria was somewhat higher in all fiber types after training. Z-band widths were not affected by eccentric training. It is concluded that skeletal musculature adapts itself in a functional manner to the extreme tension demands put on them. Improved coordination and reorganization of the contractile apparatus of muscle fibers are the determining mechanisms of this adaptation.

  • 9. Kim, Chang
    et al.
    Takala, Timo
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Karpakka, Jarmo
    Training effects of electrically induced dynamic contractions in human quadriceps muscle.1995Inngår i: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 66, s. 251-255Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effects of electrically induced dynamic muscle contractions on muscle endurance, strength, morphology and enzymatic adaptation were studied in seven male physical education students. The training program consisted of electrically induced one-leg extensions on a modified Krogh cycle with a 30-Watt (W) load for 60 min, 3 times a week for 4 weeks. Muscle fiber type composition was unchanged, but diffusional capacity was increased after electromyostimulation training. The endurance capacity in the trained leg increased by 82% (p < 0.01), but there were no significant changes in citrate synthase, phosphofructokinase activities, and carbonic anhydrase III and myoglobin contents, suggesting that neural adaptation and learning were more important factors for the increased endurance capacity than enzymatic adaptation. Prolyl 4-hydroxylase activity, a marker of collagen biosynthesis, increased 3-fold (p < 0.01) as a result of the training. This could be due to muscle damage caused by electrically induced muscle contractions. In conclusion, electrically induced dynamic muscle contractions can increase muscle endurance without clear concominant changes in muscle morphologic and enzymatic adaptation. Increased prolyl 4-hydroxylase activity could suggest muscle damage caused by electrically induced muscle contractions.

  • 10.
    Meckbach, Jane
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Lundvall, Suzanne
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    2nd World Summit on Physical Education: Magglingen 2005 värnade idrottsämnets roll som hälso- och kulturbärare2006Inngår i: Idrott & Hälsa, ISSN 0281-5338, Vol. 133, nr 2, s. 24-25Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    År 1999 anordnades en konferens i Berlin, First World Summit, med syfte att öka insikten om de positiva effekterna av idrottsundervisning. Konferensen syftade även till att öka kunskapen hos politiker, media, och allmänhet om idrottsämnets svåra situation runt om i världen. Befintlig forskning inom området presenterades och mötet gav utrymme till att stärka nätverk och koordinera planer för aktioner.

    Arrangören för denna konferens var International Council of Sport Scienceand Physical Education (ICSSPE), med säte i Berlin. Organisationen har ca 250 medlemsorganisationer runt om i världen, statliga och icke statliga(Non governmental, NGO) intressenter inom områdena idrott och hälsa och vetenskap. Organisationen stöds av UNESCO. I korthet kom representanter från ett 80-tal länder överens om följande uttalande:

    Idrottsundervisning är en rättighet för alla barn och en grundläggande´komponent i deras utveckling och utbildning.

    Strategier och aktioner behövs för att säkerställa att en kvalitativ idrottsundervisning genomförs och stöds över hela världen.

    Konferensen föreslog även att FN skulle utlysa ett ”International Year of Sport and Physical Education”, vilket också genomfördes 2005.

    I slutet av förra året anordnade ICPSSE ett andra möte i Magglingen, Schweiz i syfte att följa upp vad som hänt med idrottsämnets status och analysera eventuella förändringar.

    I Ken Hardmans och Joseph Marshalls genomgång gavs dystra besked, liten förändring hade ägt rum i jämförelse med den tidigare undersökningen(Worldwide Survey of PE). En något annan bild framträdde i Uwe Pühses och Markus Gerbers studie, vilken var av mer kvalitativ karaktär. I deras studie presenterades bland annat behovet av att ta fram kvalitetskriterier för personlig och social utveckling inom idrottsämnet. I ett slutanförande ”Making the political case for physical education” betonade Professor Margaret Talbot vikten av effektiva strategier för att kunna säkerställa och vidareutveckla idrottsundervisningen som en viktig del av utbildning i allmänhet.

    Mötet utmynnade i en allmän deklaration, som bland annat innefattar en uppmaning till regeringar att följa de mål som fastställts under ”International Year of Sport and Physical Education” och som understryker idrottsämnets unika roll inom kultur, hälsa och utveckling.

    Mötesdeltagarna uppmanades att arbeta för att:

    Implementera de aktionsförslag som beslutades 1999.

    Det angelägna behovet av en översyn och en förbättring av utbildning och fortbildning av idrottslärare synliggörs.

    Etablera och/eller stärka nationella, regionala och lokala nätverk i syfte att sprida praktiska råd om undervisning byggda på mångvetenskaplig forskning och beprövad erfarenhet.

    Utveckla samarbetsformer med regeringsorgan och andra beslutsfattare för att främja idrottsundervisning och skolidrott för barn; dess bidrag till hälsa, livslångt deltagande i idrott, dans och fysisk aktivitet, och dess värde för de utbildnings- och sociala system inom vilka de lever och verkar. ICSSPE åtar sig att, på internationell bas, verka för fortsatt forskning inom området, samt spridning av ”god praktik” och framtagandet av ett argumentationsmaterial för främjande av idrottsundervisning. Vidare avser organisationen att utveckla internationella kvalitetskriterier för idrottsundervisning i skolan.

  • 11.
    Nilsson, Johnny
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Kraepelien-Strid, Eva
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Friluftsliv och naturmiljöaktivitet i skolan2012Inngår i: Idrottsdidaktiska utmaningar / [ed] Larsson, H. & Meckbach, J, Stockholm, Stockholm: Liber, 2012, 2, s. 154-163Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 12.
    Nilsson, Johnny
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Kraepelien-Strid, Eva
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Friluftsliv och naturmiljöaktiviteter i skolan2007Inngår i: Idrottsdidaktiska utmaningar, Stockholm: Liber , 2007, s. 154-163Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 13.
    Sahlin, Kent
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Forskningsgruppen Mitokondriell funktion och metabolisk kontroll.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Effects of prolonged exercise on the contractile properties of human quadriceps muscle.1995Inngår i: European Journal of Applied Physiology and Occupational Physiology, ISSN 0301-5548, E-ISSN 1432-1025, Vol. 71, s. 180-186Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The contractile properties of the quadriceps muscle were measured in seven healthy male subjects before, during and after prolonged cycling to exhaustion. Special efforts were made to obtain measurements immediately after exercise. The exercise intensity corresponded to about 75% of estimated maximal O2 uptake and time to exhaustion was mean 85 (SEM 9) min. At the end of the cycling heart rate and perceived exertion for the legs were 94% and 97% of maximal values, respectively. Maximal voluntary isometric force (MVC) had decreased after 5 min of exercise to a mean 91 (SEM 4)% of the pre-exercise value (P < 0.05) and decreased further to a mean 82 (SEM 6) and mean 66 (SEM 5)% after 40-min cycling and at exhaustion, respectively. A new finding was that during recovery reversal of MVC occurred in different phases where the half recovery time of the initial rapid phase was about 2 min. The MVC was a mean 80 (SEM 2)% of the pre-exercise value after 30 min and was not affected by superimposed electrical stimulation. Maximal voluntary concentric and eccentric forces decreased to 74% and 80% of initial values at exhaustion (P < 0.05). The kinetics of isometric contraction expressed as the time between 5% and 50% of tension (rise time) and the time between 95% and 50% of tension (relaxation time) were not significantly affected by the prolonged cycling. The electromechanical delay measured as the time between the first electrical stimulus and 5% of tension decreased from a mean 32 (SEM 1) ms at rest to a mean 26.6 (SEM 0.6) ms at fatigue (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

  • 14.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Ledarskap och friluftsliv2011Inngår i: Lärande i friluftsliv: perspektiv och ämnesdidaktiska exempel / [ed] Suzanne Lundvall, Stockholm: Gymnastik- och idrottshögskolan, GIH , 2011, s. 25-33Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 15.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Neuromuscular aspects of eccentric knee extensor actions: effects of electrical stimulation, age, gender and training1998Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The overall aim of this thesis was to study the effects of electrical stimulation, age, gender and training on the torque- and EMG-velocity relationships during eccentric knee extensor muscle actions in man. An isokinetic custom-built dynamometer was evaluated and used throughout the thesis.

    During maximal voluntary efforts eccentric torque output was similar to isometric and did not change with velocity. Superimposing electrical stimulation onto a maximal effort caused a specific increase in eccentric torque output. Submaximal electrical stimulation alone also produced a relatively higher eccentric than concentric torque. These results indicate the presence of a neural tension-regulating mechanism during maximal voluntary eccentric muscle actions in man.

    The hypothesis that such a mechanism would be more pronounced in children than adultswas not corroborated by the results from children, pre- and postpuberty. The adult pattern of interdependence between torque, EMG and muscle action type seemed to be established before puberty in both males and females. Comparisons between genders indicated a higher eccentric to concentric ratio of electromechanical eficiency at high velocity in postpuberty and adult females.

    Training with either pure eccentric or concentric maximal isokinetic muscle actions resulted in mode and velocity specific adaptations, particularly for eccentric training, in peak torque, muscle cross-sectional area, electromechanical efficiency and cross education, that is increase in strength of the contralateral leg. On the other hand, no or only minor training effects were seen on mean torque, muscle fibre morphology, eccentric to concentric EMG ratios and antagonist muscle activity.

    The expression of net eccentric torque output during maximal voluntary eccentric knee extensor actions have shown several distinct features separating it from concentric and isometric actions. Clarification of the underlying neuromuscular mechanisms remains a challenge for future research.

  • 16.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Arvidsson, Britt
    Thorstensson, Alf
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Specific effects of eccentric and concentric training on muscle strength and morphology in humans.1998Inngår i: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 79, s. 49-57Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this study was to compare pure eccentric and concentric isokinetic training with respect to their possible specificity in the adaptation of strength and morphology of the knee extensor muscles. Ten moderately trained male physical education students were divided into groups undertaking eccentric (ETG) and concentric (CTG) training. They performed 10 weeks of maximal isokinetic (90 degrees x s(-1)) training of the left leg, 4x10 repetitions - three times a week, followed by a second 10-week period of similar training of the right-leg. Mean eccentric and concentric peak torques increased by 18% and 2% for ETG and by 10% and 14% for CTG, respectively. The highest increase in peak torque occurred in the eccentric 90 degrees x s(-1) test for ETG (35%) whereas in CTG strength gains ranged 8%-15% at velocities equal or lower than the training velocity. Significant increases in strength were observed in the untrained contra-lateral leg only at the velocity and mode used in ipsilateral training. Cross-sectional area of the quadriceps muscle increased 3%-4% with training in both groups, reaching statistical significance only in ETG. No major changes in muscle fibre composition or areas were detected in biopsies from the vastus lateralis muscle for either leg or training group. In conclusion, effects of eccentric training on muscle strength appeared to be more mode and speed specific than corresponding concentric training. Only minor adaptations in gross muscle morphology indicated that other factors, such as changes in neural activation patterns, were causing the specific training-induced gains in muscle strength.

  • 17.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Bergsten, Urban
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Ledarskapscentrum vid GIH2007Inngår i: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, nr 2, s. 64-67Artikkel i tidsskrift (Annet vitenskapelig)
  • 18.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH.
    Bergsten, Urban
    Gymnastik- och idrottshögskolan, GIH.
    Teaching about Leadership or Teaching through Leadership2013Inngår i: Journal of Leadership Education, ISSN ISSN 1552-904, Vol. 12, nr 1, s. 252-259Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This article is based on experiences and convictions from teaching leadership to students on university/college level. Teaching “through” leadership rather than “about” leadership is advocated. Student learning and facilitator teaching are contrasted. Leadership is viewed more as a mutual relationship rather than certain personality traits of the leader. The importance of understanding group-processes is stressed.

  • 19.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Hård af Segerstad, Kristina
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Nilsson, Johnny
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    GIH:s rullskidprojekt:  Lärarstudenter GIH 2008 delrapport 2: 20092010Rapport (Annet vitenskapelig)
    Abstract [sv]

    Gymnastik – och idrottshögskolan, GIH, har en lång tradition av utbildning inom skidåkning. Redan 1924 genomfördes den första fjällfärden för civila studenter i Jämtland och sedan 1926 har obligatorisk utbildning i turteknik, förlagd till fjällterräng, genomförts (Schantz & Halldén, 1988). Utförsåkning och längdåkning har också länge funnits med som inslag i vinterutbildningen. För närvarande har samtliga program vid GIH (lärarprogrammet, tränarprogrammet och hälsopedagogprogrammet) en obligatorisk vinterutbildning i fjällmiljö, omfattande omkring tre högskolepoäng (cirka två veckors heltidsstudier).

    Under senare år har en ökande andel av de antagna studenterna uppvisat brister vad gäller grundläggande skidfärdighet, vilket försvårat möjligheterna till breddning och fördjupning, såväl teoretiskt som praktiskt, under vinterutbildningen. De stora skillnaderna i färdighet hos studenterna innebär, förutom svårigheterna att tekniskt och didaktiskt arbeta med olika aspekter av skidåkning med heterogena grupper under en så begränsad tid, även att säkerheten under turåkningsmomentet får större fokus än vad som tidigare varit fallet. Den bristande skidåkningsfärdigheten hos vissa studenter kan bland annat få till följd att de får svårt att genomföra turåkningen. Den vanligtvis otillräckliga snötillgången i Mellansverige gör att träning på "hemmaplan" blir svår att genomföra.

    I syfte att söka komma till rätta med denna problematik genomfördes ett delprojekt inom ramen för det så kallade "GIH 2008-projektet". Studenter som själva ansåg sig ha en bristande skidteknik, eller betraktade sig som nybörjare i skidåkning, erbjöds delta i projektet. Utöver möjligheten att stödja studenter som saknade eller hade liten tidigare erfarenhet av skidåkning, fanns här möjlighet att prova olika metodiker för didaktiska studier.

    Denna åtgärd från GIH:s sida att bistå studenter som av geografiska, klimatologiska eller av andra orsaker inte haft möjlighet att tidigare skaffa sig skiderfarenhet kommer sannolikt att bli än mer betydelsefull i framtiden.

    Nedan presenteras data för stakmomentet och diagonalåkningen i projektet. Ett antal utrustningar, bestående av skidskor, stavar och rullskidor införskaffades och studenterna fick en möjlighet att under några veckor träna rullskidåkning

    Såväl kvalitativa som kvantitativa metoder användes för utvärdering av träningsprocesser. Denna utvärdering baserades på videofilmning och datorbaserad videoanalys.

  • 20.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Thomsson, Bertil
    Kastförmåga hos 7-åriga flickor och pojkar1994Inngår i: Tidskrift i gymnastik och idrott, nr 6, s. 26-31Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 21.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Thorstensson, Alf
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Effects of eccentric versus concentric training on thigh muscle strength and EMG.2005Inngår i: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, Vol. 26, s. 45-52Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this study was to compare pure eccentric and concentric strength training regarding possible specific effects of muscle action type on neuromuscular parameters, such as a decreased inhibition during maximal voluntary eccentric actions. Two groups of young healthy adult men performed 10 weeks of either eccentric or concentric unilateral isokinetic knee extensor training at 90 degrees.s(-1), 4 sets of 10 maximal efforts, 3 days a week. Knee extensor torque and surface EMG from the quadriceps and hamstring muscle groups were collected and quantified in a window between 30 and 70 degrees knee angle (range of motion 90-5 degrees ) during maximal voluntary eccentric and concentric knee extensor actions at 30, 90, and 270 degrees.s(-1). Changes in strength of the trained legs revealed more signs of specificity related to velocity and contraction type after eccentric than concentric training. No major training effects were present in eccentric to concentric ratios of agonist EMG or in relative antagonist (hamstring) activation. Thus, for the trained leg, the muscle action type and speed specific changes in maximal voluntary eccentric strength could not be related to any effects on neural mechanisms, such as a selective increase in muscle activation during eccentric actions. Interestingly, with both types of training there were specific cross-education effects, that is, action type and velocity specific increases in strength occurred in the contralateral, untrained, leg, accompanied by a specific increase in eccentric to concentric EMG ratio after eccentric training.

  • 22.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Thorstensson, Alf
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Electrically evoked eccentric and concentric torque-velocity relationships in human knee extensor muscles.2000Inngår i: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 169, s. 63-69Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The torque-velocity relationship, obtained during in situ conditions in humans, demonstrates a levelling-off of eccentric torque output at the isometric torque level, at least for knee extensor actions. In contrast, the in vitro force-velocity relationship for animal muscle preparations is characterized by a sharp rise in eccentric force from isometric maximum. A force-regulating 'protective' mechanism has been suggested during maximal voluntary high-tension eccentric muscle actions. To investigate this phenomenon, maximal voluntary and three different levels of submaximal, electrically induced torques were compared during isometric and low velocity (10, 20 and 30 degrees s-1) isokinetic eccentric and concentric knee extensor actions in 10 healthy, moderately trained subjects. Eccentric torque was higher than isometric during electrically evoked, but not during maximal voluntary muscle actions. In contrast, concentric torque was significantly lower than isometric for both maximal voluntary and submaximal, electrically evoked conditions. Comparisons of normalized torques (isometric value under each condition set to 100%) demonstrated that the maximal voluntary eccentric torque had to be increased by 20%, and the isometric by 10% in order for the maximal voluntary torque-velocity curve to coincide with the electrically stimulated submaximal ones. These results support the notion that a tension-regulating mechanism is present primarily during eccentric maximal voluntary knee extensor actions.

  • 23.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Thorstensson, Alf
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Muscle strength and electromyogram in boys and girls followed through puberty.2000Inngår i: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 81, s. 54-61Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The main purpose of this study was to investigate the changes in anthropometric measures and muscle strength that occur during puberty in children from the age of 11 to 16 years. Special attention was paid to possible gender- and muscle action-type-specific alterations in torque/velocity and EMG/velocity characteristics. Sixteen children participated in the study (9 boys and 7 girls). Eccentric and concentric muscle strength was measured on an isokinetic dynamometer at angular velocities of 45, 90 and 180 degrees x s(-1). Simultaneously, a surface electromyogram (EMG) was recorded from the quadriceps muscle. At the age of 11, the boys and girls exhibited equal anthropometric measures and strength performance. In both genders, body measures and muscle strength increased significantly during the 5-year period, with larger increases being recorded for the boys. In addition, the boys increased selectively their eccentric torque per body mass, indicating an action-type-specific change in muscle quality. The general shape of the torque/velocity relationship exhibited an adult-like pattern both before and after puberty, and did not differ between genders. Both pre- and postpuberty, myoelectric activity was generally lower during eccentric than concentric actions, the highest values occurring for both genders in the concentric 180 degrees x s(-1) test. Ratios of eccentric to concentric torque per EMG, which reflect electromechanical efficiency, showed no significant changes with age. A significant velocity- and gender-specific change in electromechanical efficiency was observed at the highest speed at postpuberty, where the ratio for the girls was higher than for the boys.

  • 24.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Thorstensson, Alf
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Muscle strength and myoelectric activity in prepubertal and adult males and females.1994Inngår i: European Journal of Applied Physiology and Occupational Physiology, ISSN 0301-5548, E-ISSN 1432-1025, Vol. 69, s. 81-87Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The compare children and adults of both genders with respect to torque-velocity, electromyogram (EMG)-velocity and torque-EMG relationships during maximal voluntary knee extensor muscle actions. Four groups of purpose of this investigation was to ten subjects each were studied comprising 11-year-old girls and boys and female and male physical education students (22-35 years). Maximal voluntary eccentric (lengthening) and concentric (shortening) actions of the knee extensors were performed at the constant velocities of 45, 90 and 180 degrees.s-1. Average values for torque and EMG activity, recorded by surface electrodes from the quadriceps muscle, were taken for the mid 40 degrees of the 80 degrees range of motion. The overall shapes of the torque- and EMG-velocity relationships were similar for all four groups, showing effects of velocity under concentric (torque decrease and EMG increase) but not under eccentric conditions. Eccentric torques were always greater than velocity-matched concentric ones, whereas the eccentric EMG values were lower than the concentric ones at corresponding velocities. Torque output per unit EMG activity was clearly higher for eccentric than for concentric conditions and the difference was of similar magnitude for all groups. Thus, the torque-EMG-velocity relationships would appear to have been largely independent of gender and to be fully developed at a prepubertal age.

  • 25.
    Seger, Jan
    et al.
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    Westing, Stephen
    Hanson, Mats
    Karlson, Eddy
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    A new dynamometer measuring concentric and eccentric muscle strength in accelerated, decelerated, or isokinetic movements1988Inngår i: European Journal of Applied Physiology and Occupational Physiology, ISSN 0301-5548, E-ISSN 1432-1025, Vol. 57, s. 526-530Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new computerized dynamometer (the SPARK System) is described. The system can measure concentric and eccentric muscle strength (torque) during linear or nonlinear acceleration or deceleration, isokinetic movements up to 400 degrees.s-1, and isometric torque. Studies were performed to assess: I. validity and reproducibility of torque measurements; II. control of lever arm position; III. control of different velocity patterns; IV. control of velocity during subject testing; and, V. intra-individual reproducibility. No significant difference was found between torque values computed by the system and known torque values (p greater than 0.05). No difference was present between programmed and external measurement of the lever arm position. Accelerating, decelerating and isokinetic velocity patterns were highly reproducible, with differences in elapsed time among 10 trials being never greater than 0.001 s. Velocity during concentric and eccentric isokinetic quadriceps contractions at 30 degrees.s-1, 120 degrees.s-1 and 270 degrees.s-1 never varied by more than 3 degrees.s-1 among subjects (N = 21). Over three days of testing, the overall error for concentric and eccentric quadriceps contraction peak torque values for 5 angular velocities between 30 degrees.s-1 and 270 degrees.s-1 ranged from 5.8% to 9.0% and 5.8% to 9.6% respectively (N = 25). The results indicate that the SPARK System provides valid and reproducible torque measurements and strict control of velocity. In addition, the intra-individual error is in accordance with those reported for other similar devices.

  • 26. Svedenhag, Jan
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    Running on land and in water: comparative exercise physiology1992Inngår i: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 24, nr 10, s. 1155-1160Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effect of water immersion on cardiorespiratory and blood lactate responses during running was investigated. Wearing a buoyant vest, 10 trained runners (mean age 26 yr) ran in water at four different and specified submaximal loads (target heart rates 115, 130, 145, and 155-160 beats.min-1) and at maximal exercise intensity. Oxygen uptakes (VO2), heart rates, perceived exertion, and blood lactate concentrations were measured. Values were compared with levels obtained during treadmill running. For a given VO2, heart rate was 8-11 beats.min-1 lower during water running than during treadmill running, irrespective of exercise intensity. Both the maximal oxygen uptake (4.03 vs 4.60 1 x min-1) and heart rate (172 vs 188 beats.min-1) were lower during water running. Perceived exertion (legs and breathing) and the respiratory exchange ratio (RER) were higher during submaximal water running than during treadmill running, while ventilation (1 x min-1) was similar. The blood lactate concentrations were consistently higher in water than on the treadmill, both when related to VO2 and to %VO2max. Partly in conformity with earlier cycle ergometer studies, these data suggest that immersion induces acute cardiac adjustments that extend up to the maximal exercise level. Furthermore, both the external hydrostatic load and an altered running technique may add to an increased anaerobic metabolism during supported water running.

  • 27. Westing, Stephen
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    Eccentric and Concentric Torque-Velocity Characteristics, Torque Output Comparisons, and Gravity Effect Torque Corrections for the Quadriceps and Hamstring Muscles in Females1989Inngår i: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, Vol. 10, nr 3, s. 175-180Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this study was to assess and compare eccentric (ECC) and concentric (CONC) torque output of the quadriceps and hamstring muscles and to analyze the effect of gravity effect torque (GET) correction on the calculation of the hamstring/quadriceps peak torque quotient (H/Q quotient). Twenty female subjects performed maximal voluntary CONC and ECC contractions of the quadriceps and hamstring muscles at five isokinetic lever arm velocities from 60 degrees/s to 360 degrees/s. Peak torque was measured and corrected for GET. Mean ECC torque did not significantly change with increasing ECC velocity for either the quadriceps or hamstring muscles (P greater than 0.05). Mean CONC torques were significantly lower than the corresponding ECC torques (P less than 0.05) and decreased with increasing CONC velocity. At each test velocity, the CONC H/Q quotient was significantly lower than the corresponding ECC H/Q quotient (P less than 0.05). Mean H/Q quotients did not significantly change with increasing velocity for either the CONC or ECC tests (means: 0.46 and 0.57; P greater than 0.05). Mean H/Q quotients not corrected for GET significantly increased with increasing velocity for the CONC (0.61 to 0.78; P less than 0.05), but not ECC tests (0.66 to 0.71; P greater than 0.05). The results indicate that the ECC torque-velocity curve is essentially level for both quadriceps and hamstring muscles. The present findings point strongly toward the necessity of correcting for GET when calculating both CONC and ECC H/Q quotients.(ABSTRACT TRUNCATED AT 250 WORDS)

  • 28. Westing, Stephen
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Karlson, Eddy
    Ekblom, Björn
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Björn Ekbloms forskningsgrupp.
    Eccentric and concentric torque-velocity characteristics of the quadriceps femoris in man1988Inngår i: European Journal of Applied Physiology and Occupational Physiology, ISSN 0301-5548, E-ISSN 1432-1025, Vol. 58, s. 100-104Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The primary purpose of this investigation was to study the eccentric and concentric torque-velocity characteristics of the quadriceps femoris in man using a recently developed combined isometric, concentric and eccentric controlled velocity dynamometer (the SPARK System). A secondary purpose was to compare the method error associated with maximal voluntary concentric and eccentric torque output over a range of testing velocities. 21 males (21-32 years) performed on two separate days maximal voluntary isometric, concentric and eccentric contractions of the quadriceps femoris at 4 isokinetic lever arm velocities of 0 degree.s-1 (isometric), 30 degrees.s-1, 120 degrees.s-1 and 270 degrees.s-1. Eccentric peak torque and angle-specific torques (measured every 10 degrees from 30 degrees to 70 degrees) did not significantly change from 0 degrees.s-1 to 270 degrees.s-1 (p greater than 0.005) with the exception of angle-specific 40 degrees torque, which significantly increased; p less than 0.05). The mean method error was significantly higher for the eccentric tests (10.6% +/- 1.6%) than for the concentric tests (8.1% +/- 1.7%) (p less than 0.05). The mean method error decreased slightly with increasing concentric velocity (p greater than 0.05), and increased slightly with increasing eccentric velocity (p greater than 0.05). A tension restricting neural mechanism, if active during maximal eccentric contractions, could possibly account for the large difference seen between the present eccentric torque-velocity results and the classic results obtained from isolated animal muscle.

  • 29. Westing, Stephen
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Thorstensson, Alf
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Effects of electrical stimulation on eccentric and concentric torque-velocity relationships during knee extension in man1990Inngår i: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 140, s. 17-22Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this study was to examine the effects of electrical stimulation on torque output during knee extension. Nine well-trained males (19-43 years) performed maximal voluntary, electrically evoked and superimposed eccentric and concentric knee extensions at velocities of 60, 180 and 360 degrees s-1, plus an isometric test (torque was always recorded at a 60 degree knee angle). Fifty-hertz stimulation was applied percutaneously at the maximum tolerated voltage (140-200 V). By superimposing electrical stimulation, eccentric torque could be increased by an average of 21-24% above the voluntary level (P less than 0.05). No corresponding differences were observed between superimposed and voluntary torques under isometric or concentric conditions. Electrically evoked torque also exceeded voluntary torque under eccentric conditions (11-12%, P less than 0.05), but was less under isometric and concentric conditions (-10 to -52%, P less than 0.05). Within the limitations of the study, it was concluded that eccentric knee extension torque under maximal voluntary conditions does not represent the maximal torque-producing capacity. The action of a neural inhibitory mechanism was proposed as an explanation for this finding. If active, this mechanism may protect against the extreme muscle tension that could otherwise develop under truly maximal eccentric conditions.

  • 30. Westing, Stephen
    et al.
    Seger, Jan
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap.
    Thorstensson, Alf
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC).
    Isoacceleration: a new concept of resistive exercise1991Inngår i: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 23, nr 5, s. 631-635Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study presents the concept of constant (iso-) accelerative and decelerative exercise and compares concentric and eccentric torque output during isoaccelerative and isodecelerative movements with that during comparable constant velocity (isokinetic) conditions. Twelve men (19-42 yr) performed maximal voluntary concentric and eccentric knee extensions at velocities of 120 and 240 degrees.s-1 (isokinetic) and at accelerations of 180 and 720 degrees.s-2 (both isoaccelerative and isodecelerative) between 10 degrees and 90 degrees knee angles. At 50 degrees, the 180 and 720 degrees.s-2 tests had velocities of 120 and 240 degrees.s-1, respectively, and thus torque comparisons could be made at a corresponding position and velocity. No difference was seen among the isoaccelerative, isodecelerative, or isokinetic angle- and velocity-specific torques for either the concentric or eccentric tests (P greater than 0.05). The results demonstrated that, under conditions of maximal voluntary effort, movement speed as such (within the range studied) was the essential determinant of muscle force--not whether this speed was attained during accelerative, decelerative, or constant velocity movements. As a testing and training modality, the controlled acceleration technique, particularly eccentric deceleration and concentric accleration, appears to offer advantages as compared with existing methods, since it more faithfully reflects the contraction conditions during natural strength-requiring movements.

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