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| 2. |
- Bergh, U, et al.
(författare)
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Maximal oxygen uptake and muscle fiber types in trained and untrained humans.
- 1978
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Ingår i: Medicine and science in sports. - 0025-7990. ; 10:3, s. 151-4
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Tidskriftsartikel (refereegranskat)abstract
- Maximal oxygen uptake (Vo2 max) was determined in 138 male and 41 female human subjects and muscle fiber composition (gastrocnemius and vastus lateralis) in 53 of the males. Highest values for Vo2 max were 7.38 1 x min-1 and 4.341 x min-1 in males and females, respectively. In relation to body weight the highest values were 94 and 77 ml x (kg x min)-1. Athletes participating in endurance events had very high Vo2 max and predominantly slow twitch (ST) fiber populations whereas weight lifters attained rather low values for Vo2 max and had a higher percentage of fast twitch (FT) fibers. Among subjects with the same fiber composition, Vo2 max was higher in the athletes than in the moderately trained. All groups taken together demonstrated a positive relationship between Vo2 max and the relative number of ST fibers (r = 0.67). For endurance and strength athletes r = 0.72 and for the moderately trained r = 0.34, both correlation coefficients being significant.
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| 3. |
- Ekblom, Björn, et al.
(författare)
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Effect of changes in arterial oxygen content on circulation and physical performance.
- 1975
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Ingår i: Journal of applied physiology. - 0021-8987. ; 39:1, s. 71-5
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the effect of different levels of arterial oxygen content on hemodynamic parameters during exercise nine subjects performed submaximal bicycle or treadmill exercise and maximal treadmill exercise under three different experimental conditions: 1) breathing room air (control); 2) breathing 50% oxygen (hyperoxia); 3) after rebreathing a carbon monoxide gas mixture (hypoxia). Maximal oxygen consumption (Vo2 max) was significantly higher in hyperoxia (4.99 1/min) and significantly lower in hypoxia (3.80 1/min) than in the control experiment (4.43 1/min). Physical performance changes in parallel with Vo2 max. Maximal cardiac output (Qmax) was similar in hyperoxia as in control but was significantly lower in hypoxia mainly due to a decreased stroke volume. A correlation was found between Vo2 max and transported oxygen, i.e., Cao2 times Amax, thus suggesting that central circulation is an important limiting factor for human maximal aerobic power. During submaximal work HR was decreased in hyperoxia and increased in hypoxia. Corresponding Q values were unchanged except for a reduction during high submaximal exercise in hyperoxia.
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| 4. |
- Fernström, Erik, et al.
(författare)
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Die Gebirgsexpedition Trantre
- 1979
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Annan publikation (populärvet., debatt m.m.)abstract
- Im Winter 1978 wurde die Gebirgsexpedition „Fjällmarsch TranTre“ von sechs jungen Männern auf Skiern durchgeführt. Er begann am 1. März in Transtrand und ging entlang der schwedischen Bergkette bis nach Treriksröset. Dann reisten sie nach Süden zum Torne Träsk bahnhof, den sie am 27. April erreichten.Sie wanderten 50 Tage lang und legten eine Strecke von 1500 km zurück. Die jungen Männer dokumentierten ihre Skireise und die verfassten Texte handeln von ihren Vorbereitungen, der Reiseroute, den Etappen, der Ausrüstung, dem Gepäck, dem Essen, den Campingplätzen, der Fußpflege, den Skiern, dem Wetter, der Sonne, der Kälte, dem Schlaf sowie den Tieren und der Natur.Die körperliche Anstrengung wurde wissenschaftlich untersucht und führte zu vier Veröffentlichungen, die nachfolgend als verschiedene Einträge in digitales wissenschaftliches Archiv (DiVA) aufgeführt sind:Schantz, Peter et al. 1982. Training-induced increase in myofibrillar ATPase intermediate fibers in human skeletal muscle. Muscle & Nerve 5:628-636.Schantz, Peter et al. 1983. Adaptation of human skeletal muscle to endurance training of long duration. Clin. Physiol 3:141-151.Schantz, Peter. 1986. Plasticity of human skeletal muscle - with special reference to effectsof physical training on enzyme levels of the NADH shuttles and phenotypicexpression of slow and fast isoforms of myofibrillar proteins, Acta Physiol Scand, vol 128, Suppl.558, pp 1-64. Schantz, Peter. 1980. Långtur - om 150 turåkning längs den svenska fjällkedjan. Stockholm: Trygg-Hansa.
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| 5. |
- Fernström, Erik
(författare)
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Fjällmarsch Trantre
- 1979
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Annan publikation (populärvet., debatt m.m.)abstract
- Under vintern 1978 genomfördes Fjällmarsch TranTre på skidor av de sex unga män som har skrivit denna dokumentation av skidturen. Den startade den 1 mars i Transtrand och fortsatte längs den svenska fjällkedjan upp till Treriksröset. Därefter färdades de söderut till tågstationen Torne träsk, som de kom till den 27 april. De hade då tillryggalagt en sträcka på 1500 km under 50 dagar.Texterna handlar om deltagarna, deras förberedelser, färdvägen, dagsetapperna, utrustningen, packningen, maten, lägerplatserna, fotvården, skidorna, vädret, solen, kylan, sömnen, samt djuren och naturen. Det fysiska arbetet studerades vetenskapligt och gav upphov till fyra publikationer som anges nedan som olika poster i DiVA:Schantz, Peter et al. 1982. Training-induced increase in myofibrillar ATPase intermediate fibers in human skeletal muscle. Muscle & Nerve 5:628-636.Schantz, Peter et al. 1983. Adaptation of human skeletal muscle to endurance training of long duration. Clin. Physiol 3:141-151.Schantz, Peter. 1986. Plasticity of human skeletal muscle - with special reference to effectsof physical training on enzyme levels of the NADH shuttles and phenotypicexpression of slow and fast isoforms of myofibrillar proteins, Acta Physiol Scand, vol 128, Suppl.558, pp 1-64. Schantz, Peter. 1980. Långtur - om 150 turåkning längs den svenska fjällkedjan. Stockholm: Trygg-Hansa.
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| 6. |
- Forsberg, Artur, 1943-, et al.
(författare)
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Styrkans betydelse vid längdåkning
- 1979
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Ingår i: Svensk skidsport : organ för Svenska skidförbundet. - 0049-2671. ; :9, s. 21-24
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Grillner, S, et al.
(författare)
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Intra-abdominal pressure changes during natural movements in man.
- 1978
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772 .- 1365-201X. ; 103:3, s. 275-83
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Tidskriftsartikel (refereegranskat)abstract
- The weight of the upper part of the trunk is partially transmitted to the pelvis via the vertebral column. If the muscle walls around the abdominal cavity are contracted, a high pressure can be generated within the cavity (greater than 200 mmHg). The abdominal space can them transmit part of weight to, e.g., the upper part of the body, Intra-abdominal pressure recordings have been performed during locomotion and other natural movements with intragastric pressure recordings. With each step, there is a phasic variation in pressure, with its peak coinciding with that of the peak vertical force exerted by the leg against the ground. The peak values increase progressively with the speed of walking/running up to a mean of 38 mmHg and with trough values of 16 mmHg. The phasic variations with each step is due to a phasic activation of the abdominal muscles, with an EMG activity starting 50 ms or more before foot contact. If an extra load is put on the back, the posture changes and at the highest speed of running the pressure values are significantly higher than without this additional load. After a jump down from a moderate height of 0.4 m, the average increase is 89 mmHg and can often exceed 100 mmHg. These pressure changes are large and will presumably act to unload the spine under the prevailing biomechanical conditions and, in addition, there will no doubt be an effect on the circulatory system.
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| 8. |
- Hultén, B, et al.
(författare)
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Relationship between isometric endurance and fibre types in human leg muscles.
- 1975
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772 .- 1365-201X. ; 93:1, s. 135-8
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Tidskriftsartikel (refereegranskat)abstract
- Relationship between isometric endurance performance at 50% of maximal voluntary isometric contraction (MCV) and skeletal muscle fibre composition has been elucidated in 19 physical education students. This was found to be linear and the equation corresponded to: y=9.35 + 1.093x; r=0.70 (endurance time expressed in seconds and fibre composition as percent slow twitch muscle fibres (ST) of the vastus lateralis muscle). As it is assumed from previous studies that similar isometric tensions preferentially recruit fast twitch muscle fibres (FT) and that the muscle at the point of exhaustion exhibits maximal values for lactate accumulation, it is suggested that lactate formed in FT fibres is released and stored in nonrecruited ST fibres. The ability to sustain similar isometric tension would then be depending on how large the fraction of ST fibres is that can serve as a lactaterecipient for lactate producing FT fibres.
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| 9. |
- Karlsson, J, et al.
(författare)
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LDH isozymes in skeletal muscles of endurance and strength trained athletes.
- 1975
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772 .- 1365-201X. ; 93:2, s. 150-6
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Tidskriftsartikel (refereegranskat)abstract
- Muscle biopsy samples were obtained from arm and leg muscles of endurance and strength trained athletes, respectively. Total LDH activity as well as occurrence and activity of LDH isozymes were determined. Comparing the results from the athletes with those from non-trained subjects with corresponding fibre compositions, it was found that the endurance athletes had a lower total LDH activity, a higher relative activity of the most heart-specific isozymes. LDH (1 + 2), and, on electrophoretic separation, a complete absence of LDH (4 + 5) in both arm and leg muscles. As compared to the untrained material the strength trained athletes tended to have a higher total LDH activity, a similar distribution of relative isozyme activities, and, in the leg muscles, a strong electrophoretic band corresponding to LDH 5, the most skeletal muscle specific isozyme.
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| 10. |
- Komi, P V, et al.
(författare)
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Skeletal muscle fibres and muscle enzyme activities in monozygous and dizygous twins of both sexes.
- 1977
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772 .- 1365-201X. ; 100:4, s. 385-92
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Tidskriftsartikel (refereegranskat)abstract
- Significance of the genetic component in determining the interindividual variation observed in skeletal muscle fibre composition and enzyme activities was investigated in 31 pairs of male and female monozygous (MZ) and dizygous (DZ) twins, whose ages ranged in all but one pair (11 years) from 15 to 24 years. Percent distribution of slow twitch muscle fibres and activities of Ca2+ and Ng2+ stimulated ATPases, creatine phosphokinase, myokinase, phosphorylase, lactate dehydrogenase (LDH) and distribution of its isozyme LDH-1 were all analyzed in biopsy samples taken from the vastus lateralis muscle. The data disclosed that in contrast to DZ twins the MZ twins of both sexes had an essentially identical muscle fibre composition. Calculation of the heritability estimate for this parameter gave the values of 99.5% and 92.8%, respectively for males and females. In contrast to the fibre composition presence of a significant genetic component was not observed in any of the enzyme activities studied. It was concluded that there is a predominant genetic influence on the skeletal muscle fibre composition in man, and thus also on the potential capacity of the muscles to perform work.
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