scholarly journals Muscle fiber typology substantially influences time to recover from high-intensity exercise

2020 ◽  
Vol 128 (3) ◽  
pp. 648-659 ◽  
Author(s):  
Eline Lievens ◽  
Malgorzata Klass ◽  
Tine Bex ◽  
Wim Derave
Keyword(s):  
Maximal Voluntary Contraction ◽  
A Priori ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Resonance Spectroscopy ◽  
Mean Power ◽  
Test Protocol ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch

Human fast-twitch muscle fibers generate high power in a short amount of time but are easily fatigued, whereas slow-twitch fibers are more fatigue resistant. The transfer of this knowledge to coaching is hampered by the invasive nature of the current evaluation of muscle typology by biopsies. Therefore, a noninvasive method was developed to estimate muscle typology through proton magnetic resonance spectroscopy in the gastrocnemius. The aim of this study was to investigate whether male subjects with an a priori-determined fast typology (FT) are characterized by a more pronounced Wingate exercise-induced fatigue and delayed recovery compared with subjects with a slow typology (ST). Ten subjects with an estimated higher percentage of fast-twitch fibers and 10 subjects with an estimated higher percentage of slow-twitch fibers underwent the test protocol, consisting of three 30-s all-out Wingate tests. Recovery of knee extension torque was evaluated by maximal voluntary contraction combined with electrical stimulation up to 5 h after the Wingate tests. Although both groups delivered the same mean power across all Wingates, the power drop was higher in the FT group (−61%) compared with the ST group (−41%). The torque at maximal voluntary contraction had fully recovered in the ST group after 20 min, whereas the FT group had not yet recovered 5 h into recovery. This noninvasive estimation of muscle typology can predict the extent of fatigue and time to recover following repeated all-out exercise and may have applications as a tool to individualize training and recovery cycles. NEW & NOTEWORTHY A one-fits-all training regime is present in most sports, though the same training implies different stimuli in athletes with a distinct muscle typology. Individualization of training based on this muscle typology might be important to optimize performance and to lower the risk for accumulated fatigue and potentially injury. When conducting research, one should keep in mind that the muscle typology of participants influences the severity of fatigue and might therefore impact the results.

Na current density at and away from end plates on rat fast- and slow-twitch skeletal muscle fibers

1992 ◽  
Vol 262 (1) ◽  
pp. C229-C234 ◽  
Author(s):  
R. L. Ruff
Keyword(s):  
Skeletal Muscle ◽  
Current Density ◽  
Muscle Fibers ◽  
Postsynaptic Membrane ◽  
Na Current ◽  
End Plate ◽  
Skeletal Muscle Fibers ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch

Na current density and membrane capacitance were studied with the loose patch voltage clamp technique on rat fast- and slow-twitch skeletal muscle fibers at three different regions on the fibers: 1) the end plate border, 2) greater than 200 microns from the end plate (extrajunctional), and 3) on the end plate postsynaptic membrane. Fibers were treated with collagenase to improve visualization of the end plate and to enzymatically remove the nerve terminal. The capacitance of membrane patches was similar on fast- and slow-twitch fibers and patches of membrane on the end plate had twice the capacitance of patches elsewhere. For fast- and slow-twitch fibers, the sizes of the Na current normalized to the area of the patch were as follows: end plate greater than end plate border greater than extrajunctional. For both types of fibers, the amplitudes of the Na current normalized to the capacitance of the membrane patch were as follows: end plate approximately end plate border greater than extrajunctional. At each of the three regions, the Na current densities were larger on fast-twitch fibers and fast-twitch fibers had a larger increase in Na current density at the end plate border compared with extrajunctional membrane.

scholarly journals lncRNA-Six1 Is a Target of miR-1611 that Functions as a ceRNA to Regulate Six1 Protein Expression and Fiber Type Switching in Chicken Myogenesis

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 243 ◽  
Author(s):  
Manting Ma ◽  
Bolin Cai ◽  
Liang Jiang ◽  
Bahareldin Ali Abdalla ◽  
Zhenhui Li ◽  
...  
Keyword(s):  
Fiber Type ◽  
Muscle Fibers ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Proliferation And Differentiation ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch

Emerging studies indicate important roles for non-coding RNAs (ncRNAs) as essential regulators in myogenesis, but relatively less is known about their function. In our previous study, we found that lncRNA-Six1 can regulate Six1 in cis to participate in myogenesis. Here, we studied a microRNA (miRNA) that is specifically expressed in chickens (miR-1611). Interestingly, miR-1611 was found to contain potential binding sites for both lncRNA-Six1 and Six1, and it can interact with lncRNA-Six1 to regulate Six1 expression. Overexpression of miR-1611 represses the proliferation and differentiation of myoblasts. Moreover, miR-1611 is highly expressed in slow-twitch fibers, and it drives the transformation of fast-twitch muscle fibers to slow-twitch muscle fibers. Together, these data demonstrate that miR-1611 can mediate the regulation of Six1 by lncRNA-Six1, thereby affecting proliferation and differentiation of myoblasts and transformation of muscle fiber types.

scholarly journals Calcium accumulation by the sarcoplasmic reticulum in two populations of chemically skinned human muscle fibers. Effects of calcium and cyclic AMP.

1982 ◽  
Vol 79 (4) ◽  
pp. 603-632 ◽  
Author(s):  
G Salviati ◽  
M M Sorenson ◽  
A B Eastwood
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Cyclic Amp ◽  
Muscle Fibers ◽  
Human Muscle ◽  
Wide Range ◽  
Ca Uptake ◽  
Human Muscles ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch

In previous efforts to characterize sarcoplasmic reticulum function in human muscles, it has not been possible to distinguish the relative contributions of fast-twitch and slow-twitch fibers. In this study, we have used light scattering and 45Ca to monitor Ca accumulation by the sarcoplasmic reticulum of isolated, chemically skinned human muscle fibers in the presence and absence of oxalate. Oxalate (5 mM) increased the capacity for Ca accumulation by a factor of 35 and made it possible to assess both rate of Ca uptake and relative sarcoplasmic reticulum volume in individual fibers. At a fixed ionized Ca concentration, the rate and maximal capacity (an index of sarcoplasmic reticulum volume) both varied over a wide range, but fibers fell into two distinct groups (fast and slow). Between the two groups, there was a 2- to 2.5-fold difference in oxalate-supported Ca uptake rates, but no difference in average sarcoplasmic reticulum volumes. Intrinsic differences in sarcoplasmic reticulum function (Vmax, K0.5, and n) were sought to account for the distinction between fast and slow groups. In both groups, rate of Ca accumulation increased sigmoidally as [Ca++] was increased from 0.1 to 1 microM. Apparent affinities for Ca++ (K0.5) were similar in the two groups, but slow fibers had a lower Vmax and larger n values. Slow fibers also differed from fast fibers in responding with enhanced Ca uptake upon addition of cyclic AMP (10(-6) M, alone or with protein kinase). Acceleration by cyclic AMP was adequate to account for adrenaline-induced increases in relaxation rates previously observed in human muscles containing mixtures in fast-twitch and slow-twitch fibers.

Decrease in maximal voluntary contraction by tonic vibration applied to a single synergist muscle in humans

2000 ◽  
Vol 89 (4) ◽  
pp. 1420-1424 ◽  
Author(s):  
Motoki Kouzaki ◽  
Minoru Shinohara ◽  
Tetsuo Fukunaga
Keyword(s):  
Maximal Voluntary Contraction ◽  
Vastus Lateralis ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Vastus Medialis ◽  
Force Development ◽  
Ia Afferent ◽  
Before And After ◽  
Integrated Emg

The purpose of the study was to examine the effect of prolonged tonic vibration applied to a single synergist muscle on maximal voluntary contraction (MVC) and maximal rate of force development (dF/d t max). The knee extension MVC force and surface electromyogram (EMG) from the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) during MVC were recorded before and after vibration of RF muscle at 30 Hz for 30 min. MVC, dF/d t max, and the integrated EMG (iEMG) of RF decreased significantly after prolonged tonic vibration in spite of no changes in iEMG of VL and VM. The present results indicate that MVC and dF/d t max may be influenced by the attenuated Ia afferent functions of a single synergist muscle.

Rat soleus muscle fiber responses to 14 days of spaceflight and hindlimb suspension

1992 ◽  
Vol 73 (2) ◽  
pp. S51-S57 ◽  
Author(s):  
Y. Ohira ◽  
B. Jiang ◽  
R. R. Roy ◽  
V. Oganov ◽  
E. Ilyina-Kakueva ◽  
...  
Keyword(s):  
Hindlimb Suspension ◽  
Protein Profiles ◽  
Sectional Area ◽  
Cross Sectional ◽  
Glycerophosphate Dehydrogenase ◽  
Rat Soleus Muscle ◽  
Slow Twitch ◽  
Fiber Atrophy ◽  
Slow Twitch Fibers ◽  
Fast Twitch

Morphological and enzymatic responses in fibers expressing fast, slow, or both types of myosin heavy chain (MHC) were studied in rats after 14 days of spaceflight (COSMOS 2044) or hindlimb suspension. Although the percentage of slow-twitch fibers was unchanged, a higher percentage of fibers that expressed both slow and fast MHC was observed in flight and suspended rats than in synchronous ground-based controls. The soleus was 25 and 34% smaller than control after 14 days of flight and suspension, with the reduction in fiber cross-sectional area (CSA) being greater in slow- than in fast-twitch fibers in both experimental groups. The activities of succinate dehydrogenase (SDH) and alpha-glycerophosphate dehydrogenase (GPD) were not significantly affected by flight or suspension. The total SDH activity (i.e., SDH activity x CSA) decreased significantly in the slow-twitch fibers of the flight and the fast-twitch fibers of the suspended rats, in large part due to fiber atrophy. A shift in MHC expression in 14 and 9% of the fibers in flight and suspended rats occurred without a change in myosin adenosinetriphosphatase activity. The SDH and GPD activities of the fibers that expressed both slow and fast MHC were slightly higher than the slow-twitch fibers and slightly lower than the fast-twitch fibers. These data indicate that events were initiated within 14 days of spaceflight or suspension that began to reconfigure the protein profiles of 9–14% of the slow-twitch fibers from typical slow-twitch toward those of fast-twitch fibers, while all fibers were dramatically losing total protein.(ABSTRACT TRUNCATED AT 250 WORDS)

S-nitrosylation and S-glutathionylation of Cys134 on troponin I have opposing competitive actions on Ca2+ sensitivity in rat fast-twitch muscle fibers

2017 ◽  
Vol 312 (3) ◽  
pp. C316-C327 ◽  
Author(s):  
T. L. Dutka ◽  
J. P. Mollica ◽  
C. R. Lamboley ◽  
V. C. Weerakkody ◽  
D. W. Greening ◽  
...  
Keyword(s):  
Troponin I ◽  
Muscle Fibers ◽  
Contractile Apparatus ◽  
Slow Twitch ◽  
Mechanistic Basis ◽  
Opposing Effects ◽  
Slow Twitch Fibers ◽  
Competitive Actions ◽  
Fast Twitch ◽  
Biotin Switch

Nitric oxide is generated in skeletal muscle with activity and decreases Ca2+ sensitivity of the contractile apparatus, putatively by S-nitrosylation of an unidentified protein. We investigated the mechanistic basis of this effect and its relationship to the oxidation-induced increase in Ca2+ sensitivity in mammalian fast-twitch (FT) fibers mediated by S-glutathionylation of Cys134 on fast troponin I (TnIf). Force-[Ca2+] characteristics of the contractile apparatus in mechanically skinned fibers were assessed by direct activation with heavily Ca2+-buffered solutions. Treatment with S-nitrosylating agents, S-nitrosoglutathione (GSNO) or S-nitroso- N-acetyl-penicillamine (SNAP), decreased pCa50 ( = −log10 [Ca2+] at half-maximal activation) by ~−0.07 pCa units in rat and human FT fibers without affecting maximum force, but had no effect on rat and human slow-twitch fibers or toad or chicken FT fibers, which all lack Cys134. The Ca2+ sensitivity decrease was 1) fully reversed with dithiothreitol or reduced glutathione, 2) at least partially reversed with ascorbate, indicative of involvement of S-nitrosylation, and 3) irreversibly blocked by low concentration of the alkylating agent, N-ethylmaleimide (NEM). The biotin-switch assay showed that both GSNO and SNAP treatments caused S-nitrosylation of TnIf. S-glutathionylation pretreatment blocked the effects of S-nitrosylation on Ca2+ sensitivity, and vice-versa. S-nitrosylation pretreatment prevented NEM from irreversibly blocking S-glutathionylation of TnIf and its effects on Ca2+ sensitivity, and likewise S-glutathionylation pretreatment prevented NEM block of S-nitrosylation. Following substitution of TnIf into rat slow-twitch fibers, S-nitrosylation treatment caused decreased Ca2+ sensitivity. These findings demonstrate that S-nitrosylation and S-glutathionylation exert opposing effects on Ca2+ sensitivity in mammalian FT muscle fibers, mediated by competitive actions on Cys134 of TnIf.

scholarly journals Comparison of regulated passive membrane conductance in action potential–firing fast- and slow-twitch muscle

2009 ◽  
Vol 134 (4) ◽  
pp. 323-337 ◽  
Author(s):  
Thomas Holm Pedersen ◽  
William Alexander Macdonald ◽  
Frank Vincenzo de Paoli ◽  
Iman Singh Gurung ◽  
Ole Bækgaard Nielsen
Keyword(s):  
Action Potential ◽  
Muscle Fibers ◽  
Membrane Conductance ◽  
Fiber Types ◽  
Channel Inhibition ◽  
Slow Twitch Muscle ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch ◽  
Passive Membrane

In several pathological and experimental conditions, the passive membrane conductance of muscle fibers (Gm) and their excitability are inversely related. Despite this capacity of Gm to determine muscle excitability, its regulation in active muscle fibers is largely unexplored. In this issue, our previous study (Pedersen et al. 2009. J. Gen. Physiol. doi:10.1085/jgp.200910291) established a technique with which biphasic regulation of Gm in action potential (AP)-firing fast-twitch fibers of rat extensor digitorum longus muscles was identified and characterized with temporal resolution of seconds. This showed that AP firing initially reduced Gm via ClC-1 channel inhibition but after ∼1,800 APs, Gm rose substantially, causing AP excitation failure. This late increase of Gm reflected activation of ClC-1 and KATP channels. The present study has explored regulation of Gm in AP-firing slow-twitch fibers of soleus muscle and compared it to Gm dynamics in fast-twitch fibers. It further explored aspects of the cellular signaling that conveyed regulation of Gm in AP-firing fibers. Thus, in both fiber types, AP firing first triggered protein kinase C (PKC)-dependent ClC-1 channel inhibition that reduced Gm by ∼50%. Experiments with dantrolene showed that AP-triggered SR Ca2+ release activated this PKC-mediated ClC-1 channel inhibition that was associated with reduced rheobase current and improved function of depolarized muscles, indicating that the reduced Gm enhanced muscle fiber excitability. In fast-twitch fibers, the late rise in Gm was accelerated by glucose-free conditions, whereas it was postponed when intermittent resting periods were introduced during AP firing. Remarkably, elevation of Gm was never encountered in AP-firing slow-twitch fibers, even after 15,000 APs. These observations implicate metabolic depression in the elevation of Gm in AP-firing fast-twitch fibers. It is concluded that regulation of Gm is a general phenomenon in AP-firing muscle, and that differences in Gm regulation may contribute to the different phenotypes of fast- and slow-twitch muscle.

scholarly journals Intracellular calcium movements during excitation–contraction coupling in mammalian slow-twitch and fast-twitch muscle fibers

2012 ◽  
Vol 139 (4) ◽  
pp. 261-272 ◽  
Author(s):  
Stephen M. Baylor ◽  
Stephen Hollingworth
Keyword(s):  
Action Potentials ◽  
Muscle Fibers ◽  
Mouse Muscle ◽  
Contraction Coupling ◽  
Individual Mouse ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch ◽  
Indicator Dye

In skeletal muscle fibers, action potentials elicit contractions by releasing calcium ions (Ca2+) from the sarcoplasmic reticulum. Experiments on individual mouse muscle fibers micro-injected with a rapidly responding fluorescent Ca2+ indicator dye reveal that the amount of Ca2+ released is three- to fourfold larger in fast-twitch fibers than in slow-twitch fibers, and the proportion of the released Ca2+ that binds to troponin to activate contraction is substantially smaller.

An electron microscopic study of the pigeon breast muscle

1969 ◽  
Vol 47 (4) ◽  
pp. 517-523 ◽  
Author(s):  
I. Grinyer ◽  
J. C. George
Keyword(s):  
Contractile Activity ◽  
Electron Microscopic ◽  
Sustained Activity ◽  
The Matrix ◽  
Cytological Features ◽  
Slow Twitch ◽  
Giant Size ◽  
Slow Twitch Fibers ◽  
Fast Twitch ◽  
White Fiber

The distinctive cytological features of the red and white fibers of the pigeon pectoralis muscle have been studied with the electron microscope. In the red fibers, which are more numerous, numerous fat droplets occur between the myofibrils, as do large mitochondria, some of which attain giant size (4 × 1.3 μ). The white fibers, which are larger than the red, contain fewer and smaller mitochondria whose cristae are not so closely packed and the matrix not so dense as in the mitochondria of the red fibers. The white fibers contain large concentrations of glycogen granules but not fat droplets. Conspicuously large aggregations of mitochondria occur in the subsarcolemmal region as they do also in the immediate vicinity of the capillaries of both fibers, but those of the white fibers are markedly smaller. Some myofibrils of red fibers are closely associated with the capillaries, and it is suggested that their contractile activity effects muscular pumping of the blood in the capillaries to facilitate the intramuscular transport of oxygen and metabolites. The triads of the sarcoplasmic reticulum in the white fiber occur at the level of the Z-line. In the red fiber, however, they seem to be located at the A-I junction but may also be seen at the Z-line and at varying levels between the Z-line and the A-I junction. The Z-line in the red fibers is thicker than that in the white fibers. The M-band is prominent in both types of fiber. From the nature of the intracellular organization of the two types of fiber, it is suggested that the red fibers are "slow twitch" fibers and the white fibers "fast twitch" fibers. The former are engaged in sustained activity whereas the latter are active only for short periods of time.

Glycogen-Depletion Patterns with Isometric and Isokinetic Exercise in Patients after Leg Injury

1981 ◽  
Vol 61 (1) ◽  
pp. 35-42 ◽  
Author(s):  
B. Hultén ◽  
P. Renström ◽  
G. Grimby
Keyword(s):  
Muscle Fibre ◽  
Maximal Voluntary Contraction ◽  
Isometric Exercise ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Type I ◽  
Type Ii ◽  
Glycogen Depletion ◽  
Leg Injuries ◽  
Maximal Effort

1. The glycogen-depletion patterns were studied as a measure of muscle-fibre recruitment in patients after leg injuries (fractures, ligament injuries). Intermittent isometric and dynamic isokinetic knee extension were performed with 30 and 50% of the maximal isometric torque of the injured leg. In a third group isokinetic and dynamic exercise with weights were compared by using maximal effort procedures. 2. The 30% maximal voluntary contraction programme, which corresponded to 16% of maximal voluntary contraction of the non-injured leg, resulted in glycogen depletion of type I fibres, which was significant only in the isometric exercise. In the 50% maximal voluntary contraction programme (41% of maximal voluntary contraction of the non-injured leg) depletion of type II fibres dominated and was significant with isometric exercises. In the maximal effort programmes there was a significant depletion of type II fibres. 3. Subjects with a relatively large reduction in strength or a small number of type I fibres demonstrated more depletion of these fibres than other subjects. 4. In patients with moderately reduced muscle strength and muscle fibre atrophy static or dynamic exercises using at least 50% of the actual maximal voluntary contraction can thus be used to recruit and train type II fibres.

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