Isokinetic strength, endurance, and fiber type composition in elite American paddlers

Clarkson, Priscilla M.; Kroll, Walter; Melchionda, Anthony M.

doi:10.1007/bf00421166

Cited by 44 publications

(25 citation statements)

References 23 publications

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“…Nygaard et al (1983), Schantz et al (1983) and Thorstensson et al (1975) have previously reported significant correlations between histochemically typed FT fibres and various strength indices. However, this has not been observed in other studies (Clarkson et al 1982;Frose and Houston 1985). The inconsistency of these results may be due to the limitations associated with histochemical fibre type assessment that have been described by Abernethy et al (1994).…”

Section: Resultscontrasting

confidence: 72%

Differences in muscle contractile characteristics among bodybuilders, endurance trainers and control subjects

Jürimäe

Abernethy

Quigley

et al. 1997

European Journal of Applied Physiology

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The purpose of this investigation was to compare the myosin heavy chain (MHC) isoform expression of the triceps brachii muscle and isoinertial, isometric and isokinetic strength indices in competitive bodybuilders (CB, n = 5), recreational resistance trainers (RT, n = 5), endurance-trained rowers (ER, n = 5) and control (C, n = 5) subjects. Muscle tissue samples were analysed for MHC isoform content using 6% sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The CB possessed significantly smaller (P < 0.05) percentage of MHC type IIb proteins [12.92 (SD 7.08)%] than RT [30.08 (SD 6.58)%] ER [31.20 (SD 2.74)%] and C [38.22 (SD 2.95)%] groups (i.e. CB < RT approximately ER < C). While the content of MHC type IIa isoforms did not differ significantly between the two resistance-trained groups [CB = 55.76 (SD 5.38)%; RT = 45.72 (SD 7.8)%], CB presented significantly more type IIa MHC isoforms than ER [42.84 (SD 2.98)%] and C [34.72 (SD 1.57)%] subjects (i.e. CB approximately RT > ER approximately C). The MHC type I protein content did not differ significantly among RT [24.20 (SD 4.89)%] ER [25.38 (SD 1.67)%] and C [27.06 (SD 1.81)%] groups. The CB [31.32 (SD 2.67)%] presented significantly more type I MHC isoforms only in comparison with RT. However, when changes in the percentage of MHC type I isoforms were converted to effect sizes (ES), it appeared that low statistical power rather than the absence of an effect accounted for the nonsignificant differences between CB and other groups (i.e. CB > RT approximately ER approximately C). Significant differences existed in isoinertial strength among the trained athletes (i.e. CB > RT > ER approximately C), while isometric and isokinetic strength were not significantly different among any of the trained groups. However, the ES transformation of data demonstrated that large differences existed between resistance-trained groups and ER for isometric and isokinetic strength (i.e. CB approximately RT > ER approximately C). A statistically significant negative correlation (P < 0.001) was found between MHC type IIb isoforms and isoinertial strength index (r = -0.68). The MHC type IIa proteins were positively related to all the strength measures considered (r = 0.51 0.61; P < 0.001). These data demonstrated different patterns of MHC isoform expression among the different groups of athletes and it is suggested that these differences on occasion may affect the expression of strength.

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Section: Resultscontrasting

confidence: 72%

Differences in muscle contractile characteristics among bodybuilders, endurance trainers and control subjects

Jürimäe

Abernethy

Quigley

et al. 1997

European Journal of Applied Physiology

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“…These relationships were still present when the type-1 ®bre occurrence was normalized for body mass and height. Thus, we suggest, in contrast to Clarksson et al (1982), that muscular endurance in untrained female subjects is determined mainly by the muscle ®bre characteristics and only secondarily by other factors such as body mass. However, when comparing muscle morphology data with mechanical output one also has to bear in mind that only one of the muscles contributing to the mechanical output is analysed with respect to muscle morphology.…”

Section: Discussionmentioning

confidence: 61%

“…Furthermore, a relationship between isometric endurance at 50% maximal voluntary contraction (MVC) and the relative proportion of type-1 ®bres has been demonstrated (HulteÂ n et al 1975). However, other studies have suggested that factors such as initial isokinetic strength, maximal isometric strength and body size characteristics in¯uence fatigue patterns more than muscle ®bre composition does (Clarksson et al 1980(Clarksson et al , 1982Kroll et al 1980;Litch®eld et al 1984;Patton et al 1990). …”

Section: Introductionmentioning

confidence: 92%

Inter-relationship between muscle morphology, mechanical output and electromyographic activity during fatiguing dynamic knee-extensions in untrained females

Wretling

Henriksson-Larsén

Gerdle

1997

European Journal of Applied Physiology

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Changes in mechanical performance and electromyographic activity during fatiguing dynamic knee-extensions were evaluated with respect to muscle fibre type composition of the vastus lateralis muscle in nine sedentary female [23 (3) years] volunteers. The subjects performed 150 repetitive maximum knee-extensions using a Cybex dynamometer at 1.57 rad x s(-1). EMG activity was recorded from the vastus lateralis, the vastus medialis and the rectus femoris muscles. For each contraction, mean power frequency (MPF) and the root mean square (RMS) of the EMG were calculated, simultaneously with the peak torque (PT), contractional work (CW) and the mean power (MP). The MPF showed an initial decrease followed by a stable phase. The RMS increased during the initial seven contractions, after which a period of variability was displayed until about the 60th contraction. At the plateau level (last 50 contractions) the relative RMS values were not significantly different from the initial values. The PT, CW and MP increased during the initial five to ten contractions, after which a two-phase pattern was displayed, with a gradual decline followed by a stable phase. The absolute plateau level of MPF for the vastus lateralis muscle showed a significant negative correlation with the area percentage of type-1 fibres (r = -0.71). Significant correlations were also demonstrated to occur between the absolute plateau levels of PT, CW and MP and the relative proportion of type-1 fibres (r = 0.80, r = 0.82 and r = 0.82 respectively). Thus, in female subjects the mechanical performance and the MPF during fatigue are at least partly determined by muscle morphology.

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“…However, the introduction of the isokinetic dynamometer, more than 30 years ago (Hislop and Perrine 1967), which allowed in vivo muscle torque measurements at controlled movement velocities, initiated a series of studies on in vivo human muscle contraction. Specific interest was focused on the relationship between the torque produced at fast versus slow movement velocities and fiber type proportions in the contracting muscle, typically kneeextensor muscles (Clarkson et al 1982;Coyle et al 1979;Froese and Houston 1985;Ivy et al 1981;Larsson et al 1979;Ryushi and Fukunaga 1986;Suter et al 1993; Thorstensson et al 1976). However, divergent or conflicting results have been reported in the literature.…”

Section: Introductionmentioning

confidence: 99%

Relationship between in vivo muscle force at different speeds of isokinetic movements and myosin isoform expression in men and women

Gür

Gransberg

et al. 2003

Eur J Appl Physiol

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In an attempt to explore the relationship between force production during voluntary contractions at different speeds of isokinetic movement and the myofibrillar protein isoform expression in humans, an improved isokinetic dynamometer that corrects for gravitation, controls for acceleration and deceleration, and identifies a maximum voluntary activation was used. Muscle torque recordings were compared at the same muscle length (knee angle) and the torque was calculated as the average torque at each angle over a large knee angle range (75 degrees -25 degrees ) to reduce the influence of small torque oscillation on the calculated torque. Muscle torque at fast (240 degrees s(-1)) versus slow (30 degrees s(-1)) speeds of movement, torque normalized to muscle cross-sectional area (specific tension), and absolute torque at fast speeds of movement were measured in 34 young healthy male and female short-, middle-, and long-distance runners. The relationship between the different measures of muscle function and the expression of myosin heavy chain (MyHC) isoforms using enzyme-histochemical and electrophoretic protein separation techniques were investigated. A significant correlation between the 240 degrees s(-1) vs 30 degrees s(-1) torque ratio and the relative area of the type II fibers and type II MyHC isoforms were observed in both the men (r=0.74; P<0.001) and the women (r=0.81; P<0.05). Thus, the present results confirm a significant relationship between in vivo human muscle function and the MyHC isoform expression in the contracting muscle.

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Isokinetic strength, endurance, and fiber type composition in elite American paddlers

Cited by 44 publications

References 23 publications

Differences in muscle contractile characteristics among bodybuilders, endurance trainers and control subjects

Differences in muscle contractile characteristics among bodybuilders, endurance trainers and control subjects

Inter-relationship between muscle morphology, mechanical output and electromyographic activity during fatiguing dynamic knee-extensions in untrained females

Relationship between in vivo muscle force at different speeds of isokinetic movements and myosin isoform expression in men and women

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