Search results for "Muscle"
showing 10 items of 3397 documents
Motor imagery and cortico-spinal excitability: A review
2016
International audience; Motor imagery (MI) has received a lot of interest during the last decades as its chronic or acute use has demonstrated several effects on improving sport performances or skills. The development of neuroimagery techniques also helped further our understanding of the neural correlates underlying MI. While some authors showed that MI, motor execution and action observation activated similar motor cortical regions, transcranial magnetic stimulation (TMS) studies brought great insights on the role of the primary motor cortex and on the activation of the cortico-spinal pathway during MI. After defining MI and describing the TMS technique, a short report of MI activities on…
Increased fascicle length but not patellar tendon stiffness after accentuated eccentric-load strength training in already-trained men
2020
Purpose This study examined whether additional external load during the eccentric phase of lower limb strength training exercises led to greater adaptations in knee extensor strength, muscle architecture, and patellar tendon properties than traditional concentric–eccentric training in already-trained men. Methods Twenty-eight men accustomed to strength training were randomized to undertake 10 weeks of supervised traditional (TRAD) or accentuated eccentric loading (AEL) or continue their habitual unsupervised (CON) strength training. TRAD and AEL trained 2∙week−1 with a six-repetition maximum (RM) session and a ten-RM session. TRAD used the same external load in both concentric and eccentric…
Branched-Chain Amino Acid Deprivation Decreases Lipid Oxidation and Lipogenesis in C2C12 Myotubes
2022
Impaired lipid metabolism is a common risk factor underlying several metabolic diseases such as metabolic syndrome and type 2 diabetes. Branched-chain amino acids (BCAAs) that include valine, leucine and isoleucine have been proven to share a role in lipid metabolism and hence in maintaining metabolic health. We have previously introduced a hypothesis suggesting that BCAA degradation mechanistically connects to lipid oxidation and storage in skeletal muscle. To test our hypothesis, the present study examined the effects of BCAA deprivation and supplementation on lipid oxidation, lipogenesis and lipid droplet characteristics in murine C2C12 myotubes. In addition, the role of myotube contract…
Dietary intake and strength training adaptation in 50-70 -year old men and women : with special reference to muscle mass, strength, serum anabolic ho…
2007
Frailty has been defined as an age-related decrease of the physiologic systems that results in weakness, weight loss and decreased functional performance, thus increasing the risk of disability. The physical characteristics of frailty are affected by the amount of muscle mass and strength. Strength training (ST) can alleviate age-related declines in muscle mass, strength and physical function. However, there is controversy regarding whether dietary intake can improve the effects of ST. The present thesis assessed the effects of dietary intake (DI) on muscular, hormonal and metabolic adaptations to ST in healthy 50-70 year old people. In cross-sectional study I, maximal strength of the leg e…
Proof of Concept of Therapeutic Gene Modulation of MBNL1/2 in Myotonic Dystrophy
2022
La distrofia miotónica tipo 1 es una enfermedad genética rara multisistémica que afecta a 1 de cada 3000-8000 personas. La causa molecular de la enfermedad proviene de repeticiones tóxicas “CTG” en el gen DMPK (DM Protein Kinase). Tras la transcripción, estas repeticiones forman una estructura de horquilla que se une con alta afinidad a la familia de proteínas MBNL (Muscleblind-like) que agota su función de regulación de la poliadenilación y el splicing alternativo postranscripcional en numerosos transcritos. La pérdida de función de MBNL provoca una cascada de efectos posteriores, que eventualmente conducen a síntomas clínicos que incluyen miotonía, debilidad y atrofia muscular, cataratas,…
Intramyocellular topography of lipid droplets and OXPAT in obesity and type II diabetes
2010
Nowadays in the westernized world, high caloric diet and sedentarism are driving populations to accumulate ectopic fat, especially in skeletal muscle. Such is associated with the development of insulin resistance (IR) related metabolic diseases, as type II diabetes (T2D) and obesity (OB). Like IR individuals, athletes also show high intramyocellular lipids (IMCL) contents, denoting qualitative rather than quantitative differences between insulin sensitive (IS) and IR individuals IMCL. PAT proteins and OXPAT specifically, are among the main regulators of lipid droplets (LDs) in skeletal muscle. We hypothesized that different IS profiles are distinguishable through LD and OXPAT localization a…
Effects of high-fat diet and physical activity on pyruvate dehydrogenase kinase-4 in mouse skeletal muscle
2012
Background. The expression of PDK4 is elevated by diabetes, fasting and other conditions associated with the switch from the utilization of glucose to fatty acids as an energy source. It is previously shown that peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a master regulator of energy metabolism, coactivates in cell lines pyruvate dehydrogenase kinase-4 (PDK4) gene expression via the estrogen-related receptor α (ERRα). We investigated the effects of long-term high-fat diet and physical activity on the expression of PDK4, PGC-1α and ERRα and the amount and function of mitochondria in skeletal muscle. Methods. Insulin resistance was induced by a high-fat (HF) diet for…
Proprioceptive response strength in the primary sensorimotor cortex is invariant to the range of finger movement
2023
Available online 13 February 2023 Proprioception is the sense of body position and movement that relies on afference from the proprioceptors in muscles and joints. Proprioceptive responses in the primary sensorimotor (SM1) cortex can be elicited by stim- ulating the proprioceptors using evoked (passive) limb movements. In magnetoencephalography (MEG), propri- oceptive processing can be quantified by recording the movement evoked fields (MEFs) and movement-induced beta power modulations or by computing corticokinematic coherence (CKC) between the limb kinematics and cortical activity. We examined whether cortical proprioceptive processing quantified with MEF peak strength, relative beta supp…
Effects of resistance training frequency on muscle strength, activity and mass during a 24-week intervention in the elderly
2016
Elderly populations are increasingly affected by sarcopenia, dynapenia and osteoporosis. They all increase frailty and decrease quality of life and life-expectancy. Resistance training (RT) has been reported extensively as a tool that can prevent, counter and in some cases reverse the course of the abovementioned diseases. Several studies covering RT adaptations in elderly populations have investigated periods between 6 up to 88 weeks with different frequencies, from 1 to 3 trainings / week and a wide range of intensities (30-85% or one repetition maximum) and different volumes. The aim of this study was to investigate the effect of different training frequencies (one, two or three times / …