Re : MYTHES STUPIDES : changer frequement de routine
Un peu de lecture de différentes études en relation avec l'hyperplasie...
Ce qu'il faut admettre, c'est qu'il y a peu d'humains qui mettraient un de leurs muscle à charcuter avant et après entraînement ou stretching intensif...
Ces cellules satellites augmentent avec l'entraînement et sont par la suite activées à la suite de lésions musculaires pour régénérer les tissus et pour en créer d'autres supplémentaires (1 à 3% au naturel, ce qui est infime presque rien comme dit au tout début). Elle s'activent grâce aux entraînements, au stretching, aux produits etc...
Vous êtes d'accord avec moi que le corps s'adapte à tout depuis la nuit des temps, plus ou moin vite. Il est logique que lorsqu'un stress intense est exercé sur un muscle, celui ci va s'adapter en recrutant plus de fibres, en augmentant sa taille, en renforçant ses tissus conjonctifs sans parler de la densité osseuse qui croît, l'influx nerveux qui augmente etc... Et pourquoi pas augmenter le nombre de fibre alors que ceci a été prouvé sur des personnes sous stéroïdes et GH?!?! (Voir études par la suite)
On produit aussi de la GH naturellement non?? (Plusieurs personnes diplômés de doctorat en physio, en prepa physique et scientifique me l'ont confirmé pendant mes études)
Si après tout ça vous êtes toujours focalisé sur cette idée que l'hyperplasie n'existe pas, je me la ferme et ne dis plus rien car a vouloir ouvrir les yeux sur des faits réels qui faussent ce qui a été dit pendant des années, je m'en prend plein la gueul!
Merci et bonne lecture
C'est bien ce qu'il me semblait Corbillard.
Personal trainer, il est temps de dégainer ton anglais scientifique et de justifier tes propos ! ;-)
Je savais que contredire ce qui a très souvent été dit allait en faire réagir plus d'un...
Allez de la lecture pour vous provenant de pubmed, reconnu dans le monde de la recherche.
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Morphological and biochemical evidence of muscle hyperplasia following weight-lifting exercise in rats.
AuthorsTamaki T, et al. Show all Journal
Am J Physiol. 1997 Jul;273(1 Pt 1):C246-56.
Affiliation
Department of Physiology, Tokai University School of Medicine, Kanagawa, Japan.
Abstract
We used a rat model of weight lifting to examine the serial biochemical and morphological changes following muscle fiber hyperplasia during 14 days of exercise. [3H]thymidine and [14C]leucine labeling were used to determine the serial changes in cellular mitotic activity and the level of amino acid uptake and myosin synthesis. Morphological changes were assessed with light and transmission electron microscopy, whereas proliferation of cells was evaluated immunohistochemically with 5-bromo-2'-deoxyuridine (BrdU). The intensity of the exercise and degree of muscle damage were monitored by serum creatine kinase (CK) activity. Damaged fibers were sparsely distributed, and a significant CK leakage was observed 30-60 min after exercise. Anti-BrdU-positive cells were observed in damaged fibers and at the periphery of undamaged fibers. Changes typical of muscle regeneration were observed; however, the formation of new fibers in the interstitial space was also evident. The mitotic activity also changed and reflected the appearance of anti-BrdU-positive cells and activated satellite cells. Amino acid uptake increased during the first week of exercise, probably reflecting muscle hypertrophy and synthesis of other noncontractile related proteins. The uptake also increased during the second week, probably due to hyperplasia, a finding also supported by electron microscopy. Our results suggest that one bout of weight-lifting exercise in untrained rats induced muscle hyperplasia following regeneration. The process of muscle hyperplasia was activated by muscle fiber damage in our model.
PMID 9252463 [PubMed - indexed for MEDLINE]
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Skeletal muscle fiber hyperplasia.
AuthorsAntonio J, et al. Show all Journal
Med Sci Sports Exerc. 1993 Dec;25(12):1333-45.
Affiliation
Department of Cell Biology and Neurosciences, University of Texas Southwestern Medical Center, Dallas 75235-9039.
Abstract
Skeletal muscle enlargement in adult animals has been ascribed primarily to changes in fiber cross-sectional area (i.e., fiber hypertrophy); however, recent evidence from several laboratories suggests strongly that fiber hyperplasia contributes to muscle mass increases in adult animals and possibly human athletes. Scientists have used three models to study the cellular mechanisms of muscle enlargement: compensatory hypertrophy, stretch, and exercise. Each of these models has provided direct as well as indirect evidence supporting the occurrence of muscle fiber hyperplasia. Direct counts of muscle fibers using nitric acid digestion techniques have shown that both exercise and stretch overload result in significant increases (range = 9-52%) in fiber number. Indirect fiber counts using histological cross-sections have suggested fiber hyperplasia (range = 10-82%) in all three models. Additionally, the expression of embryonic myosin isoforms have provided indirect evidence for new fiber formation in stretch overloaded muscle. Furthermore, satellite cells have been shown to be involved in muscle fiber hyperplasia in stretch and exercise.
PMID 8107539 [PubMed - indexed for MEDLINE]
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Effects of anabolic steroids on the muscle cells of strength-trained athletes.
AuthorsKadi F, et al. Show all Journal
Med Sci Sports Exerc. 1999 Nov;31(11):1528-34.
Affiliation
Department of Integrative Medical Biology, Umeå University, Sweden.
[email protected]
Abstract
PURPOSE: Athletes who use anabolic steroids get larger and stronger muscles. How this is reflected at the level of the muscle fibers has not yet been established and was the topic of this investigation.
METHODS: Muscle biopsies were obtained from the trapezius muscles of high-level power lifters who have reported the use of anabolic steroids in high doses for several years and from high-level power lifters who have never used these drugs. Enzyme-immunohistochemical investigation was performed to assess muscle fiber types, fiber area, myonuclear number, frequency of satellite cells, and fibers expressing developmental protein isoforms.
RESULTS: The overall muscle fiber composition was the same in both groups. The mean area for each fiber type in the reported steroid users was larger than that in the nonsteroid users (P < 0.05). The number of myonuclei and the proportion of central nuclei were also significantly higher in the reported steroid users (P < 0.05). Likewise, the frequency of fibers expressing developmental protein isoforms was significantly higher in the reported steroid users group (P < 0.05).
CONCLUSION: Intake of anabolic steroids and strength-training induce an increase in muscle size by both hypertrophy and the formation of new muscle fibers. We propose that activation of satellite cells is a key process and is enhanced by the steroid use. The incorporation of the satellite cells into preexisting fibers to maintain a constant nuclear to cytoplasmic ratio seems to be a fundamental mechanism for muscle fiber growth. Although all the subjects in this study have the same level of performance, the possibility of genetic differences between the two groups cannot be completely excluded.
PMID 10589853 [PubMed - indexed for MEDLINE]
Full text: Lippincott Williams & Wilkins
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Effects of high-intensity resistance training on untrained older men. II. Muscle fiber characteristics and nucleo-cytoplasmic relationships.
AuthorsHikida RS, et al. Show all Journal
J Gerontol A Biol Sci Med Sci. 2000 Jul;55(7):B347-54.
Affiliation
Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens 45701, USA.
[email protected]
Abstract
During growth and repair of skeletal muscle fibers, satellite cells become activated, undergo mitosis, and a daughter nucleus becomes incorporated into the muscle fiber to increase myonuclear numbers. An increase in myonuclei appears to be required for this postnatal growth. This study examined whether muscle fibers of elderly men can hypertrophy with strength training and, if so, whether they have the capacity to incorporate nuclei into the fibers. The sarcoplasmic area associated with each myonucleus was calculated in nine elderly men before and after 16 weeks of strength training, and compared to nine elderly control men. Muscle fiber type changes and myosin heavy chain composition were also compared. All major fiber types (I, IIA, IIB) became significantly larger after training, and a transition of type IIB fibers to IIA occurred with training. The area occupied by each fiber type correlated with myosin heavy chain percentage, and both of these changed similarly with strength training. The cytoplasm-to-myonucleus ratio increased, but not significantly (p = .07), with muscle fiber hypertrophy. Number of myonuclei per fiber and myonuclei per unit length of muscle fiber increased, but not significantly. Cross-sectional areas of the muscle fibers in untrained elderly men were much smaller than in untrained young men (when compared with our earlier studies). Training increased the sizes of the elderly muscle fibers to that of the untrained young men. This hypertrophy of muscle fibers by 30% with training resulted in no change in the cytoplasm-to-myonucleus ratio. This suggests that the myonuclear population continues to adapt to growth stimuli in the elderly muscles.
PMID 10898248 [PubMed - indexed for MEDLINE]
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Concomitant increases in myonuclear and satellite cell content in female trapezius muscle following strength training.
AuthorsKadi F, et al. Show all Journal
Histochem Cell Biol. 2000 Feb;113(2):99-103.
Affiliation
Department of Integrative Medical Biology, Umeå University, Sweden.
[email protected]
Abstract
A skeletal muscle fibre maintains its cytoplasmic volume by means of hundreds of myonuclei distributed along its entire length. Therefore it is hypothesised that changes in fibre size would involve modifications in myonuclear number. In this study, we have examined whether 10 weeks of strength training can induce changes in the number of myonuclei and satellite cells in female trapezius muscles. Biopsies were taken pre- and posttraining from the upper part of the descending trapezius muscle of nine subjects. Muscle samples were analysed for fibre area and myonuclear and satellite cell number using immunohistochemistry. There was a 36% increase in the cross-sectional area of muscle fibres. The hypertrophy of muscle fibres was accompanied by an approximately 70% increase in myonuclear number and a 46% increase in the number of satellite cells. Myonuclei number was positively correlated to satellite cell number indicating that a muscle with an increased concentration of myonuclei will contain a correspondingly higher number of satellite cells. The acquisition of additional myonuclei appears to be required to support the enlargement of multinucleated muscle cells following 10 weeks of strength training. Increased satellite cell content suggests that mitotic divisions of satellite cells produced daughter cells that became satellite cells.
PMID 10766262 [PubMed - indexed for MEDLINE]
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Skeletal muscle morphology in power-lifters with and without anabolic steroids.
AuthorsEriksson A, et al. Show all Journal
Histochem Cell Biol. 2005 Aug;124(2):167-75. Epub 2005 Sep 29.
Affiliation
Department of Integrative Medical Biology, Section for Anatomy, Umeå University, 901 87 Umeå, Sweden.
Abstract
The morphological appearance of the vastus lateralis (VL) muscle from high-level power-lifters on long-term anabolic steroid supplementation (PAS) and power-lifters never taking anabolic steroids (P) was compared. The effects of long- and short-term supplementation were compared. Enzyme-immunohistochemical investigations were performed to assess muscle fiber type composition, fiber area, number of myonuclei per fiber, internal myonuclei, myonuclear domains and proportion of satellite cells. The PAS group had larger type I, IIA, IIAB and IIC fiber areas (p<0.05). The number of myonuclei/fiber and the proportion of central nuclei were significantly higher in the PAS group (p<0.05). Similar results were seen in the trapezius muscle (T) but additionally, in T the proportion of fibers expressing developmental myosin isoforms was higher in the PAS group compared to the P group. Further, in VL, the PAS group had significantly larger nuclear domains in fibers containing > or = 5 myonuclei. The results of AS on VL morphology in this study were similar to previously reported short-term effects of AS on VL. The initial effects from AS appear to be maintained for several years.
PMID 16059740 [PubMed - indexed for MEDLINE]
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Cellular adaptation of the trapezius muscle in strength-trained athletes.
AuthorsKadi F, et al. Show all Journal
Histochem Cell Biol. 1999 Mar;111(3):189-95.
Affiliation
Department of Anatomy, Umeå University, Sweden.
Abstract
The aim of this study was to elucidate the cellular events that occur in the trapezius muscle following several years of strength training. In muscle biopsies from ten elite power lifters (PL) and six control subjects (C), several parameters were studied: cross-sectional area of muscle fibres, myosin heavy chain composition (MHC) and capillary supply [capillaries around fibres (CAF) and CAF/fibre area]. A method was also developed for counting the number of myonuclei and satellite cell nuclei. The proportion of fibres expressing MHC IIA, the cross-sectional area of each fibre type and the number of myonuclei, satellite cells and fibres expressing markers for early myogenesis were significantly higher in PL than in C (P<0.05). A significant correlation between the myonuclear number and the cross-sectional area was observed. Since myonuclei in mature muscle fibres are not able to divide, we suggest that the incorporation of satellite cell nuclei into muscle fibres resulted in the maintenance of a constant nuclear to cytoplasmic ratio. The presence of small diameter fibres expressing markers for early myogenesis indicates the formation of new muscle fibres.
PMID 10094415 [PubMed - indexed for MEDLINE]
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The behaviour of satellite cells in response to exercise: what have we learned from human studies?
AuthorsKadi F, et al. Show all Journal
Pflugers Arch. 2005 Nov;451(2):319-27. Epub 2005 Aug 10.
Affiliation
Department of Physical Education and Health, Orebro University, Orebro, Sweden.
[email protected]
Abstract
Understanding the complex role played by satellite cells in the adaptive response to exercise in human skeletal muscle has just begun. The development of reliable markers for the identification of satellite cell status (quiescence/activation/proliferation) is an important step towards the understanding of satellite cell behaviour in exercised human muscles. It is hypothesised currently that exercise in humans can induce (1) the activation of satellite cells without proliferation, (2) proliferation and withdrawal from differentiation, (3) proliferation and differentiation to provide myonuclei and (4) proliferation and differentiation to generate new muscle fibres or to repair segmental fibre injuries. In humans, the satellite cell pool can increase as early as 4 days following a single bout of exercise and is maintained at higher level following several weeks of training. Cessation of training is associated with a gradual reduction of the previously enhanced satellite cell pool. In the elderly, training counteracts the normal decline in satellite cell number seen with ageing. When the transcriptional activity of existing myonuclei reaches its maximum, daughter cells generated by satellite cell proliferation are involved in protein synthesis by enhancing the number of nuclear domains. Clearly, delineating the events and the mechanisms behind the activation of satellite cells both under physiological and pathological conditions in human skeletal muscles remains an important challenge.
PMID 16091958 [PubMed - indexed for MEDLINE]
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Effects of electrical stimulation of different frequencies on the myonuclei and fiber size in human muscle.
AuthorsCabric M, et al. Show all Journal
Int J Sports Med. 1987 Oct;8(5):323-6.
Affiliation
Department of Physical Education, Faculty of Philosophy, Split University, Yugoslavia.
Abstract
Male physical education students were subjected to electrical stimulation for a period of 21 days. The stimulation was performed with alternating currents of rectangular wave form. Group I was stimulated with a frequency of 50 Hz, group II with a frequency of 2000 Hz. Before and after the experimental period, biopsies were taken from the m. gastrocnemius. The muscle fiber size and the number and size of nuclei was estimated at the light microscopic level using stereological methods. The fiber size was significantly increased only in group I. The nuclear number and the nuclear size increased significantly in both groups leading to a higher nuclear volume per unit tissue volume. It was assumed that the proliferation of nuclei is correlated to satellite cell proliferation resulting probably in hypertrophy or hyperplasia of electrostimulated skeletal muscle.
PMID 3679646 [PubMed - indexed for MEDLINE]
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riginal: 
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, en revanche je rebondi sur ton programme que tu as écrit, je trouve vraiment intéressant de découvrir d'autre "genre" de musculation, je sais pas comment appelé cela. Et je me demande, même pour un type comme moi qui ne fais que de la musculation disons basique avec pour objectif être "bodybuilder" (je met bien entre parenthèse, je ne souhaite pas être mr olympia, mais au plus proche de ce genre de physique), serait-il utile, fructifiant, voir indispensable peut-être pour boosté ma force, et donc mon volume ?! 
