נק' מוניטין:
58,701
Exp Physiol. 2015 Sep 20. doi: 10.1113/EP085267. [Epub ahead of print]
Single muscle fibre contractile properties differ between bodybuilders, power athletes and controls.
Meijer JP1,2, Jaspers RT2, Rittweger J3, Seynnes OR4, Kamandulis S5, Brazaitis M5, Skurvydas A5, Pišot R6, Šimunič B6, Narici MV7, Degens H1.
Author information
Abstract
We compared muscle fibre contractile properties of biopsies taken from m. vastus lateralis of 12 bodybuilders (BB; low- to moderate-intensity high-volume resistance training), 6 power athletes (PA; high-intensity low-volume combined with aerobic training) and 14 controls (C). Maximal isotonic contractions were performed in single muscle fibres, typed with SDS-PAGE. Fibre cross-sectional area (FCSA) was 67% and 88% (P<0.01) larger in BB than in PA and C, respectively, with no significant difference in FCSA between PA and C. Fibres of BB and PA developed a higher maximal isometric tension (32%, 50%, P < 0.01) than those of C. Specific tension (F0 ) of BB fibres was 62% and 41% lower than that of PA and C fibres (P < 0.05), respectively. Irrespective of fibre type, peak power (P) of PA fibres was 58% higher than that of BB fibres (P < 0.05), while BB fibres -despite considerable hypertrophy- had similar PP as C fibres. This work suggests that high-intensity low-volume resistance training with aerobic exercise improves PP, while low- to moderate-intensity high-volume resistance training does not affect PP and results in a reduction in F0 . We postulate that the decrease in specific tension is caused by differences in myofibrillar density and/or post-translational modifications of contractile proteins.
Single muscle fibre contractile properties differ between bodybuilders, power athletes and controls.
Meijer JP1,2, Jaspers RT2, Rittweger J3, Seynnes OR4, Kamandulis S5, Brazaitis M5, Skurvydas A5, Pišot R6, Šimunič B6, Narici MV7, Degens H1.
Author information
Abstract
We compared muscle fibre contractile properties of biopsies taken from m. vastus lateralis of 12 bodybuilders (BB; low- to moderate-intensity high-volume resistance training), 6 power athletes (PA; high-intensity low-volume combined with aerobic training) and 14 controls (C). Maximal isotonic contractions were performed in single muscle fibres, typed with SDS-PAGE. Fibre cross-sectional area (FCSA) was 67% and 88% (P<0.01) larger in BB than in PA and C, respectively, with no significant difference in FCSA between PA and C. Fibres of BB and PA developed a higher maximal isometric tension (32%, 50%, P < 0.01) than those of C. Specific tension (F0 ) of BB fibres was 62% and 41% lower than that of PA and C fibres (P < 0.05), respectively. Irrespective of fibre type, peak power (P) of PA fibres was 58% higher than that of BB fibres (P < 0.05), while BB fibres -despite considerable hypertrophy- had similar PP as C fibres. This work suggests that high-intensity low-volume resistance training with aerobic exercise improves PP, while low- to moderate-intensity high-volume resistance training does not affect PP and results in a reduction in F0 . We postulate that the decrease in specific tension is caused by differences in myofibrillar density and/or post-translational modifications of contractile proteins.
