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Plotkin DL, Mattingly ML, Anglin DA, Michel JM, Godwin JS, McIntosh MC, Bergamasco JGA, Scarpelli MC, Angleri V, Taylor LW, Willoughby DS, Mobley CB, Kavazis AN, Ugrinowitsch C, Libardi CA, Roberts MD. Skeletal muscle myosin heavy chain protein fragmentation as a potential marker of protein degradation in response to resistance training and disuse atrophy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.24.595789. [PMID: 38826385 PMCID: PMC11142278 DOI: 10.1101/2024.05.24.595789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
We sought to examine how resistance exercise (RE), cycling exercise, and disuse atrophy affect myosin heavy chain (MyHC) protein fragmentation in humans. In the first study (1boutRE), younger adult men (n=8; 5±2 years of RE experience) performed a lower body RE bout with vastus lateralis (VL) biopsies obtained immediately before, 3-, and 6-hours post-exercise. In the second study (10weekRT), VL biopsies were obtained in untrained younger adults (n=36, 18 men and 18 women) before and 24 hours (24h) after their first/naïve RE bout. These participants also engaged in 10 weeks (24 sessions) of resistance training and donated VL biopsies before and 24h after their last RE bout. VL biopsies were also examined from a third acute cycling study (n=7) and a fourth study involving two weeks of leg immobilization (n=20, 15 men and 5 women) to determine how MyHC fragmentation was affected. In the 1boutRE study, the fragmentation of all MyHC isoforms (MyHCTotal) increased 3 hours post-RE (~ +200%, p=0.018) and returned to pre-exercise levels by 6 hours post-RE. Immunoprecipitation of MyHCTotal revealed ubiquitination levels remained unaffected at the 3- and 6-hour post-RE time points. Interestingly, a greater increase in magnitude for MyHC type IIa versus I isoform fragmentation occurred 3-hours post-RE (8.6±6.3-fold versus 2.1±0.7-fold, p=0.018). In all 10weekRT participants, the first/naïve and last RE bouts increased MyHCTotal fragmentation 24h post-RE (+65% and +36%, respectively; p<0.001); however, the last RE bout response was attenuated compared to the first bout (p=0.045). The first/naïve bout response was significantly elevated in females only (p<0.001), albeit females also demonstrated a last bout attenuation response (p=0.002). Although an acute cycling bout did not alter MyHCTotal fragmentation, ~8% VL atrophy with two weeks of leg immobilization led to robust MyHCTotal fragmentation (+108%, p<0.001), and no sex-based differences were observed. In summary, RE and disuse atrophy increase MyHC protein fragmentation. A dampened response with 10 weeks of resistance training, and more refined responses in well-trained men, suggest this is an adaptive process. Given the null polyubiquitination IP findings, more research is needed to determine how MyHC fragments are processed. Moreover, further research is needed to determine how aging and disease-associated muscle atrophy affect these outcomes, and whether MyHC fragmentation is a viable surrogate for muscle protein turnover rates.
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Affiliation(s)
| | | | | | - J. Max Michel
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
| | | | | | - João G. A. Bergamasco
- MUSCULAB – Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos – UFSCar, São Carlos, SP, Brazil
| | - Maíra C. Scarpelli
- MUSCULAB – Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos – UFSCar, São Carlos, SP, Brazil
| | - Vitor Angleri
- MUSCULAB – Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos – UFSCar, São Carlos, SP, Brazil
| | - Lemuel W. Taylor
- School of Health Professions, University of Mary Hardin-Baylor, Belton, Texas, USA
| | - Darryn S. Willoughby
- School of Health Professions, University of Mary Hardin-Baylor, Belton, Texas, USA
| | | | | | - Carlos Ugrinowitsch
- School of Physical Education and Sport, University of São Paulo – USP, São Paulo, SP, Brazil
- Department of Health Sciences and Human Performance, The University of Tampa, Tampa, FL, USA
| | - Cleiton A. Libardi
- MUSCULAB – Laboratory of Neuromuscular Adaptations to Resistance Training, Department of Physical Education, Federal University of São Carlos – UFSCar, São Carlos, SP, Brazil
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2
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Sepsis-Associated Muscle Wasting: A Comprehensive Review from Bench to Bedside. Int J Mol Sci 2023; 24:ijms24055040. [PMID: 36902469 PMCID: PMC10003568 DOI: 10.3390/ijms24055040] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/21/2023] [Accepted: 03/04/2023] [Indexed: 03/08/2023] Open
Abstract
Sepsis-associated muscle wasting (SAMW) is characterized by decreased muscle mass, reduced muscle fiber size, and decreased muscle strength, resulting in persistent physical disability accompanied by sepsis. Systemic inflammatory cytokines are the main cause of SAMW, which occurs in 40-70% of patients with sepsis. The pathways associated with the ubiquitin-proteasome and autophagy systems are particularly activated in the muscle tissues during sepsis and may lead to muscle wasting. Additionally, expression of muscle atrophy-related genes Atrogin-1 and MuRF-1 are seemingly increased via the ubiquitin-proteasome pathway. In clinical settings, electrical muscular stimulation, physiotherapy, early mobilization, and nutritional support are used for patients with sepsis to prevent or treat SAMW. However, there are no pharmacological treatments for SAMW, and the underlying mechanisms are still unknown. Therefore, research is urgently required in this field.
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3
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Haug M, Reischl B, Nübler S, Kiriaev L, Mázala DAG, Houweling PJ, North KN, Friedrich O, Head SI. Absence of the Z-disc protein α-actinin-3 impairs the mechanical stability of Actn3KO mouse fast-twitch muscle fibres without altering their contractile properties or twitch kinetics. Skelet Muscle 2022; 12:14. [PMID: 35733150 PMCID: PMC9219180 DOI: 10.1186/s13395-022-00295-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 05/03/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A common polymorphism (R577X) in the ACTN3 gene results in the complete absence of the Z-disc protein α-actinin-3 from fast-twitch muscle fibres in ~ 16% of the world's population. This single gene polymorphism has been subject to strong positive selection pressure during recent human evolution. Previously, using an Actn3KO mouse model, we have shown in fast-twitch muscles, eccentric contractions at L0 + 20% stretch did not cause eccentric damage. In contrast, L0 + 30% stretch produced a significant ~ 40% deficit in maximum force; here, we use isolated single fast-twitch skeletal muscle fibres from the Actn3KO mouse to investigate the mechanism underlying this. METHODS Single fast-twitch fibres are separated from the intact muscle by a collagenase digest procedure. We use label-free second harmonic generation (SHG) imaging, ultra-fast video microscopy and skinned fibre measurements from our MyoRobot automated biomechatronics system to study the morphology, visco-elasticity, force production and mechanical strength of single fibres from the Actn3KO mouse. Data are presented as means ± SD and tested for significance using ANOVA. RESULTS We show that the absence of α-actinin-3 does not affect the visco-elastic properties or myofibrillar force production. Eccentric contractions demonstrated that chemically skinned Actn3KO fibres are mechanically weaker being prone to breakage when eccentrically stretched. Furthermore, SHG images reveal disruptions in the myofibrillar alignment of Actn3KO fast-twitch fibres with an increase in Y-shaped myofibrillar branching. CONCLUSIONS The absence of α-actinin-3 from the Z-disc in fast-twitch fibres disrupts the organisation of the myofibrillar proteins, leading to structural weakness. This provides a mechanistic explanation for our earlier findings that in vitro intact Actn3KO fast-twitch muscles are significantly damaged by L0 + 30%, but not L0 + 20%, eccentric contraction strains. Our study also provides a possible mechanistic explanation as to why α-actinin-3-deficient humans have been reported to have a faster decline in muscle function with increasing age, that is, as sarcopenia reduces muscle mass and force output, the eccentric stress on the remaining functional α-actinin-3 deficient fibres will be increased, resulting in fibre breakages.
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Affiliation(s)
- Michael Haug
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Barbara Reischl
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Stefanie Nübler
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Leonit Kiriaev
- School of Medicine, Western Sydney University, Sydney, NSW, 2560, Australia.,School of Medical Science, University of New South Wales, Sydney, NSW, Australia
| | - Davi A G Mázala
- Department of Kinesiology, College of Health Professions, Towson University, Towson, MD, USA
| | - Peter J Houweling
- Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
| | - Kathryn N North
- Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
| | - Oliver Friedrich
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.,School of Medicine, Western Sydney University, Sydney, NSW, 2560, Australia.,School of Medical Science, University of New South Wales, Sydney, NSW, Australia
| | - Stewart I Head
- School of Medicine, Western Sydney University, Sydney, NSW, 2560, Australia. .,School of Medical Science, University of New South Wales, Sydney, NSW, Australia. .,Murdoch Children's Research Institute, Melbourne, VIC, Australia.
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McCarthy O, Pitt JP, Keay N, Vestergaard ET, Tan ASY, Churm R, Rees DA, Bracken RM. Passing on the exercise baton: What can endocrine patients learn from elite athletes? Clin Endocrinol (Oxf) 2022; 96:781-792. [PMID: 35119115 PMCID: PMC9303727 DOI: 10.1111/cen.14683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 12/25/2021] [Accepted: 01/30/2022] [Indexed: 11/28/2022]
Abstract
As elite athletes demonstrate through the Olympic motto 'Citius, Altius, Fortius- Communiter', new performance records are driven forward by favourable skeletal muscle bioenergetics, cardiorespiratory, and endocrine system adaptations. At a recreational level, regular physical activity is an effective nonpharmacological therapy in the treatment of many endocrine conditions. However, the impact of physical exercise on endocrine function and how best to incorporate exercise therapy into clinical care are not well understood. Beyond the pursuit of an Olympic medal, elite athletes may therefore serve as role models for showcasing how exercise can help in the management of endocrine disorders and improve metabolic dysfunction. This review summarizes research evidence for clinicians who wish to understand endocrine changes in athletes who already perform high levels of activity as well as to encourage patients to exercise more safely. Herein, we detail the upper limits of athleticism to showcase the adaptability of human endocrine-metabolic-physiological systems. Then, we describe the growing research base that advocates the importance of understanding maladaptation to physical training and nutrition in males and females; especially the young. Finally, we explore the impact of physical activity in improving some endocrine disorders with guidance on how lessons can be taken from athletes training and incorporated into strategies to move more people more often.
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Affiliation(s)
- Olivia McCarthy
- Department of Sport and Exercise Sciences, Faculty of Science and EngineeringSwansea UniversitySwanseaUK
| | - Jason P. Pitt
- Department of Sport and Exercise Sciences, Faculty of Science and EngineeringSwansea UniversitySwanseaUK
| | - Nicky Keay
- Department of Sport and Exercise SciencesDurham UniversityDurhamUK
| | - Esben T. Vestergaard
- Department of PaediatricsRegional Hospital RandersRandersDenmark
- Department of PaediatricsAarhus University HospitalDenmark
- Steno Diabetes Centre AarhusAarhus University HospitalAarhusDenmark
| | - Abbigail S. Y. Tan
- Department of Sport and Exercise Sciences, Faculty of Science and EngineeringSwansea UniversitySwanseaUK
| | - Rachel Churm
- Department of Sport and Exercise Sciences, Faculty of Science and EngineeringSwansea UniversitySwanseaUK
| | - Dafydd Aled Rees
- Neuroscience and Mental Health Research Institute, School of MedicineCardiff UniversityCardiffUK
| | - Richard M. Bracken
- Department of Sport and Exercise Sciences, Faculty of Science and EngineeringSwansea UniversitySwanseaUK
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Barrón-Cabrera E, Torres-Castillo N, González-Becerra K, Zepeda-Carrillo EA, Torres-Valadez R, Hernández-Cañaveral I, Martínez-López E. The ACTN3 R577X polymorphism is associated with metabolic alterations in a sex-dependent manner in subjects from western Mexico. J Hum Nutr Diet 2021; 35:713-721. [PMID: 34750902 DOI: 10.1111/jhn.12948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/13/2021] [Indexed: 01/10/2023]
Abstract
BACKGROUND The ACTN3 gene is primarily expressed in fast skeletal muscle fibres. A common nonsense polymorphism in this gene is ACTN3 R577X (rs1815739), which causes an absolute deficiency of α-actinin-3 protein and alterations in muscle metabolism. Considering metabolic alterations are influenced by nutrition and genetic factors, as well as lifestyle factors, we hypothesise a possible association of the ACTN3 R577X polymorphism with metabolic alterations. METHODS In this cross-sectional study, 397 adults met the inclusion criteria. Body composition was measured by electrical bioimpedance. Dietary data were analysed using Nutritionist Pro™ software. Biochemical variables were determined by dry chemistry. Genomic DNA was extracted from peripheral leukocytes and genotyping of the ACTN3 R577X polymorphism was determined by allelic discrimination using TaqMan probes. The statistical analyses were performed using SPSS statistical software. p < 0.05 was considered statistically significant. RESULTS The ACTN3 577XX genotype was associated with high glucose, triglyceride and very low density lipoprotein-cholesterol levels and a higher frequency of hypertriglyceridaemia and insulin resistance in women. In males, the genetic variant showed a trend towards significance for insulin resistance. CONCLUSIONS The ACTN3 R577X polymorphism was associated with metabolic alterations in women and a tendency was observed in men variant carriers. Thus, this common genetic variant could be implicated in the development of chronic metabolic diseases.
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Affiliation(s)
- Elisa Barrón-Cabrera
- Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Instituto de Nutrigenética y Nutrigenómica Traslacional, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Nathaly Torres-Castillo
- Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Instituto de Nutrigenética y Nutrigenómica Traslacional, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Karina González-Becerra
- Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Instituto de Nutrigenética y Nutrigenómica Traslacional, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Eloy A Zepeda-Carrillo
- Centro Nayarita de Innovación y Transferencia de Tecnología, Universidad Autónoma de Nayarit, Tepic, Nayarit, México.,Hospital Civil Dr Antonio González Guevara, Servicios de Salud de Nayarit, Tepic, Nayarit, Mexico
| | - Rafael Torres-Valadez
- Centro Nayarita de Innovación y Transferencia de Tecnología, Universidad Autónoma de Nayarit, Tepic, Nayarit, México.,Unidad Académica de Salud Integral, Universidad Autónoma de Nayarit, Tepic, Nayarit, Mexico
| | - Iván Hernández-Cañaveral
- Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Erika Martínez-López
- Departamento de Biología Molecular y Genómica, Centro Universitario de Ciencias de la Salud, Instituto de Nutrigenética y Nutrigenómica Traslacional, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
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Kolodziej F, O’Halloran KD. Re-Evaluating the Oxidative Phenotype: Can Endurance Exercise Save the Western World? Antioxidants (Basel) 2021; 10:609. [PMID: 33921022 PMCID: PMC8071436 DOI: 10.3390/antiox10040609] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/06/2021] [Accepted: 04/10/2021] [Indexed: 01/16/2023] Open
Abstract
Mitochondria are popularly called the "powerhouses" of the cell. They promote energy metabolism through the tricarboxylic acid (TCA) cycle and oxidative phosphorylation, which in contrast to cytosolic glycolysis are oxygen-dependent and significantly more substrate efficient. That is, mitochondrial metabolism provides substantially more cellular energy currency (ATP) per macronutrient metabolised. Enhancement of mitochondrial density and metabolism are associated with endurance training, which allows for the attainment of high relative VO2 max values. However, the sedentary lifestyle and diet currently predominant in the Western world lead to mitochondrial dysfunction. Underdeveloped mitochondrial metabolism leads to nutrient-induced reducing pressure caused by energy surplus, as reduced nicotinamide adenine dinucleotide (NADH)-mediated high electron flow at rest leads to "electron leak" and a chronic generation of superoxide radicals (O2-). Chronic overload of these reactive oxygen species (ROS) damages cell components such as DNA, cell membranes, and proteins. Counterintuitively, transiently generated ROS during exercise contributes to adaptive reduction-oxidation (REDOX) signalling through the process of cellular hormesis or "oxidative eustress" defined by Helmut Sies. However, the unaccustomed, chronic oxidative stress is central to the leading causes of mortality in the 21st century-metabolic syndrome and the associated cardiovascular comorbidities. The endurance exercise training that improves mitochondrial capacity and the protective antioxidant cellular system emerges as a universal intervention for mitochondrial dysfunction and resultant comorbidities. Furthermore, exercise might also be a solution to prevent ageing-related degenerative diseases, which are caused by impaired mitochondrial recycling. This review aims to break down the metabolic components of exercise and how they translate to athletic versus metabolically diseased phenotypes. We outline a reciprocal relationship between oxidative metabolism and inflammation, as well as hypoxia. We highlight the importance of oxidative stress for metabolic and antioxidant adaptation. We discuss the relevance of lactate as an indicator of critical exercise intensity, and inferring from its relationship with hypoxia, we suggest the most appropriate mode of exercise for the case of a lost oxidative identity in metabolically inflexible patients. Finally, we propose a reciprocal signalling model that establishes a healthy balance between the glycolytic/proliferative and oxidative/prolonged-ageing phenotypes. This model is malleable to adaptation with oxidative stress in exercise but is also susceptible to maladaptation associated with chronic oxidative stress in disease. Furthermore, mutations of components involved in the transcriptional regulatory mechanisms of mitochondrial metabolism may lead to the development of a cancerous phenotype, which progressively presents as one of the main causes of death, alongside the metabolic syndrome.
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Affiliation(s)
- Filip Kolodziej
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, T12 XF62 Cork, Ireland;
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7
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Hokken R, Laugesen S, Aagaard P, Suetta C, Frandsen U, Ørtenblad N, Nielsen J. Subcellular localization- and fibre type-dependent utilization of muscle glycogen during heavy resistance exercise in elite power and Olympic weightlifters. Acta Physiol (Oxf) 2021; 231:e13561. [PMID: 32961628 DOI: 10.1111/apha.13561] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 09/13/2020] [Accepted: 09/14/2020] [Indexed: 12/16/2022]
Abstract
AIM Glycogen particles are found in different subcellular localizations, which are utilized heterogeneously in different fibre types during endurance exercise. Although resistance exercise typically involves only a moderate use of mixed muscle glycogen, the hypothesis of the present study was that high-volume heavy-load resistance exercise would mediate a pattern of substantial glycogen depletion in specific subcellular localizations and fibre types. METHODS 10 male elite weightlifters performed resistance exercise consisting of four sets of five (4 × 5) repetitions at 75% of 1RM back squats, 4 × 5 at 75% of 1RM deadlifts and 4 × 12 at 65% of 1RM rear foot elevated split squats. Muscle biopsies (vastus lateralis) were obtained before and after the exercise session. The volumetric content of intermyofibrillar (between myofibrils), intramyofibrillar (within myofibrils) and subsarcolemmal glycogen was assessed by transmission electron microscopy. RESULTS After exercise, biochemically determined muscle glycogen decreased by 38 (31:45)%. Location-specific glycogen analyses revealed in type 1 fibres a large decrement in intermyofibrillar glycogen, but no or only minor changes in intramyofibrillar or subsarcolemmal glycogen. In type 2 fibres, large decrements in glycogen were observed in all subcellular localizations. Notably, a substantial fraction of the type 2 fibres demonstrated near-depleted levels of intramyofibrillar glycogen after the exercise session. CONCLUSION Heavy resistance exercise mediates a substantial utilization of glycogen from all three subcellular localization in type 2 fibres, while mostly taxing intermyofibrillar glycogen stores in type 1 fibres. Thus, a better understanding of the impact of resistance training on myocellular metabolism and performance requires a focus on compartmentalized glycogen utilization.
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Affiliation(s)
- Rune Hokken
- Department of Sports Science and Clinical Biomechanics University of Southern Denmark Odense M Denmark
| | - Simon Laugesen
- Department of Sports Science and Clinical Biomechanics University of Southern Denmark Odense M Denmark
| | - Per Aagaard
- Department of Sports Science and Clinical Biomechanics University of Southern Denmark Odense M Denmark
| | - Charlotte Suetta
- Geriatric Research Unit Department of Geriatrics Bispebjerg‐Frederiksberg and Herlev‐Gentofte HospitalsUniversity of Copenhagen Kobenhavn Denmark
| | - Ulrik Frandsen
- Department of Sports Science and Clinical Biomechanics University of Southern Denmark Odense M Denmark
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics University of Southern Denmark Odense M Denmark
| | - Joachim Nielsen
- Department of Sports Science and Clinical Biomechanics University of Southern Denmark Odense M Denmark
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8
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Training Programs Designed for Muscle Hypertrophy in Bodybuilders: A Narrative Review. Sports (Basel) 2020; 8:sports8110149. [PMID: 33218168 PMCID: PMC7698840 DOI: 10.3390/sports8110149] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/31/2020] [Accepted: 11/16/2020] [Indexed: 01/10/2023] Open
Abstract
Bodybuilding is a sport that requires adequate training strategies in order to maximize skeletal muscle hypertrophy. The purpose of the present review was to perform a narrative assessment of the training routines designed for muscle hypertrophy used by bodybuilders. A search was carried out in the databases Pubmed/MEDLINE, Scielo, EBSCO, LILACS, SportDiscus, Web of Science, and CINAHL with the words “Resistance training” and “hypertrophy” in bodybuilders and their variations that involve the respective outcomes. Fourteen studies were identified that investigated the long-term training routines of bodybuilders. These studies demonstrate a pattern in the training organization, whereby there is a separation of training into four distinct periods: off-season, pre-contest, peak week, and post-contest. Each period has a specific spectrum of intensity load, total training volume, and exercise type (multi- or single-joint). We conclude that bodybuilding competitors employed a higher intensity load, lower number of repetitions, and longer rest intervals in the off-season than pre-contest.
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9
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Jensen R, Ørtenblad N, Stausholm MLH, Skjaerbaek MC, Larsen DN, Hansen M, Holmberg HC, Plomgaard P, Nielsen J. Heterogeneity in subcellular muscle glycogen utilisation during exercise impacts endurance capacity in men. J Physiol 2020; 598:4271-4292. [PMID: 32686845 DOI: 10.1113/jp280247] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 07/17/2020] [Indexed: 02/06/2023] Open
Abstract
KEY POINTS When muscle biopsies first began to be used routinely in research on exercise physiology five decades ago, it soon become clear that the muscle content of glycogen is an important determinant of exercise performance. Glycogen particles are stored in distinct pools within the muscles, but the role of each pool during exercise and how this is affected by diet is unknown. Here, the effects of diet and exercise on these pools, as well as their relation to endurance during prolonged cycling were examined. We demonstrate here that an improved endurance capacity with high carbohydrate loading is associated with a temporal shift in the utilisation of the distinct stores of glycogen pools and is closely linked to the content of the glycogen pool closest to actin and myosin (intramyofibrillar glycogen). These findings highlight the functional importance of distinguishing between different subcellular microcompartments of glycogen in individual muscle fibres. ABSTRACT In muscle cells, glycogen is stored in three distinct subcellular pools: between or within myofibrils (inter- and intramyofibrillar glycogen, respectively) or beneath the sarcolemma (subsarcolemmal glycogen) and these pools may well have different functions. Here, we investigated the effect of diet and exercise on the content of these distinct pools and their relation to endurance capacity in type 1 and 2 muscle fibres. Following consumption of three different diets (normal, mixed diet = MIX, high in carbohydrate = HIGH, or low in carbohydrate = LOW) for 72 h, 11 men cycled at 75% of V ̇ O 2 max until exhaustion. The volumetric content of the glycogen pools in muscle biopsies obtained before, during, and after exercise were quantified by transmission electron micrographs. The mean (SD) time to exhaustion was 150 (30), 112 (22), and 69 (18) minutes in the HIGH, MIX and LOW trials, respectively (P < 0.001). As shown by multiple regression analyses, the intramyofibrillar glycogen content in type 1 fibres, particularly after 60 min of exercise, correlated most strongly with time to exhaustion. In the HIGH trial, intramyofibrillar glycogen was spared during the initial 60 min of exercise, which was associated with levels and utilisation of subsarcolemmal glycogen above normal. In all trials, utilisation of subsarcolemmal and intramyofibrillar glycogen was more pronounced than that of intermyofibrillar glycogen in relative terms. In conclusion, the muscle pool of intramyofibrillar glycogen appears to be the most important for endurance capacity in humans. In addition, a local abundance of subsarcolemmal glycogen reduces the utilisation of intramyofibrillar glycogen during exercise.
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Affiliation(s)
- Rasmus Jensen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark
| | | | - Mette Carina Skjaerbaek
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark
| | - Daniel Nykvist Larsen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark
| | - Mette Hansen
- Department of Public Health, Aarhus University, Denmark
| | - Hans-Christer Holmberg
- Department of Health Sciences, Mid Sweden University, Sweden.,Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Stockholm, Sweden
| | - Peter Plomgaard
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen University Hospital, Denmark.,Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Joachim Nielsen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark
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10
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Cully TR, Murphy RM, Roberts L, Raastad T, Fassett RG, Coombes JS, Jayasinghe I, Launikonis BS. Human skeletal muscle plasmalemma alters its structure to change its Ca 2+-handling following heavy-load resistance exercise. Nat Commun 2017; 8:14266. [PMID: 28193999 PMCID: PMC5316829 DOI: 10.1038/ncomms14266] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 12/08/2016] [Indexed: 01/30/2023] Open
Abstract
High-force eccentric exercise results in sustained increases in cytoplasmic Ca2+ levels ([Ca2+]cyto), which can cause damage to the muscle. Here we report that a heavy-load strength training bout greatly alters the structure of the membrane network inside the fibres, the tubular (t-) system, causing the loss of its predominantly transverse organization and an increase in vacuolation of its longitudinal tubules across adjacent sarcomeres. The transverse tubules and vacuoles displayed distinct Ca2+-handling properties. Both t-system components could take up Ca2+ from the cytoplasm but only transverse tubules supported store-operated Ca2+ entry. The retention of significant amounts of Ca2+ within vacuoles provides an effective mechanism to reduce the total content of Ca2+ within the fibre cytoplasm. We propose this ability can reduce or limit resistance exercise-induced, Ca2+-dependent damage to the fibre by the reduction of [Ca2+]cyto to help maintain fibre viability during the period associated with delayed onset muscle soreness.
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Affiliation(s)
- Tanya R. Cully
- School of Biomedical Sciences, The University of Queensland,
Brisbane, Queensland
4072, Australia
| | - Robyn M. Murphy
- Department of Biochemistry & Genetics, La Trobe Institute for
Molecular Science, La Trobe University, Melbourne, Victoria
3086, Australia
| | - Llion Roberts
- School of Human Movement and Nutritional Sciences, The University of
Queensland, Brisbane, Queensland
4072, Australia
- Centre of Excellence for Applied Sport Science Research, Queensland
Academy of Sport, Brisbane, Queensland
4111, Australia
| | - Truls Raastad
- Norwegian School of Sport Sciences, Oslo
N-0806, Norway
| | - Robert G. Fassett
- School of Human Movement and Nutritional Sciences, The University of
Queensland, Brisbane, Queensland
4072, Australia
| | - Jeff S. Coombes
- School of Human Movement and Nutritional Sciences, The University of
Queensland, Brisbane, Queensland
4072, Australia
| | - Izzy Jayasinghe
- School of Biomedical Sciences, The University of Queensland,
Brisbane, Queensland
4072, Australia
- School of Biomedical Sciences, University of Leeds,
Leeds
LS2 9JT, UK
| | - Bradley S. Launikonis
- School of Biomedical Sciences, The University of Queensland,
Brisbane, Queensland
4072, Australia
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11
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Baumert P, Lake MJ, Stewart CE, Drust B, Erskine RM. Genetic variation and exercise-induced muscle damage: implications for athletic performance, injury and ageing. Eur J Appl Physiol 2016; 116:1595-625. [PMID: 27294501 PMCID: PMC4983298 DOI: 10.1007/s00421-016-3411-1] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 06/03/2016] [Indexed: 02/06/2023]
Abstract
Prolonged unaccustomed exercise involving muscle lengthening (eccentric) actions can result in ultrastructural muscle disruption, impaired excitation-contraction coupling, inflammation and muscle protein degradation. This process is associated with delayed onset muscle soreness and is referred to as exercise-induced muscle damage. Although a certain amount of muscle damage may be necessary for adaptation to occur, excessive damage or inadequate recovery from exercise-induced muscle damage can increase injury risk, particularly in older individuals, who experience more damage and require longer to recover from muscle damaging exercise than younger adults. Furthermore, it is apparent that inter-individual variation exists in the response to exercise-induced muscle damage, and there is evidence that genetic variability may play a key role. Although this area of research is in its infancy, certain gene variations, or polymorphisms have been associated with exercise-induced muscle damage (i.e. individuals with certain genotypes experience greater muscle damage, and require longer recovery, following strenuous exercise). These polymorphisms include ACTN3 (R577X, rs1815739), TNF (-308 G>A, rs1800629), IL6 (-174 G>C, rs1800795), and IGF2 (ApaI, 17200 G>A, rs680). Knowing how someone is likely to respond to a particular type of exercise could help coaches/practitioners individualise the exercise training of their athletes/patients, thus maximising recovery and adaptation, while reducing overload-associated injury risk. The purpose of this review is to provide a critical analysis of the literature concerning gene polymorphisms associated with exercise-induced muscle damage, both in young and older individuals, and to highlight the potential mechanisms underpinning these associations, thus providing a better understanding of exercise-induced muscle damage.
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Affiliation(s)
- Philipp Baumert
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Mark J Lake
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Claire E Stewart
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Barry Drust
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Robert M Erskine
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK.
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12
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Ørtenblad N, Nielsen J. Muscle glycogen and cell function - Location, location, location. Scand J Med Sci Sports 2015; 25 Suppl 4:34-40. [DOI: 10.1111/sms.12599] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2015] [Indexed: 11/28/2022]
Affiliation(s)
- N. Ørtenblad
- Department of Sports Science and Clinical Biomechanics; SDU Muscle Research Cluster; University of Southern Denmark; Odense Denmark
- Swedish Winter Sports Research Centre; Department of Health Sciences; Mid Sweden University; Sweden
| | - J. Nielsen
- Department of Sports Science and Clinical Biomechanics; SDU Muscle Research Cluster; University of Southern Denmark; Odense Denmark
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