Article
Endocrinology & Metabolism
Sarah J. Blackwood, Baptiste Jude, Theresa Mader, Johanna T. Lanner, Abram Katz
Summary: Phosphorylase, an important protein in muscle metabolism, is regulated by redox state. Experimental results show that peroxynitrite causes nitration of phosphorylase and inhibition of glycogenolysis. The redox state plays a significant role in the control of phosphorylase and glycogenolysis during repeated muscle contractions.
AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM
(2021)
Article
Physiology
Sonia Metayer-Coustard, Sophie Tesseraud, Christophe Praud, David Royer, Thierry Bordeau, Edouard Coudert, Estelle Cailleau-Audouin, Estelle Godet, Joel Delaveau, Elisabeth Le Bihan-Duval, Cecile Berri
Summary: Divergent selection on Pectoralis major pHu in chickens resulted in the creation of pHu+ and pHu- lines, with differences in carbohydrate and protein metabolism which likely affect muscle growth and energy storage capabilities. These differences were already present at hatching, indicating early mechanisms involved in the establishment of phenotypes.
FRONTIERS IN PHYSIOLOGY
(2021)
Article
Sport Sciences
Jeppe F. Vigh-Larsen, Niels Ortenblad, Joachim Nielsen, Ole Emil Andersen, Kristian Overgaard, Magni Mohr
Summary: The study investigated the relationship between muscle glycogen content and localization and high-intensity exercise performance. The results showed that changes in muscle glycogen levels can affect high-intensity exercise performance, especially at the single-fiber and subcellular levels. Additionally, carbohydrate intake also influences ratings of perceived exertion and repeated sprint ability.
MEDICINE & SCIENCE IN SPORTS & EXERCISE
(2022)
Article
Nutrition & Dietetics
Astrid M. H. Horstman, Stephen J. Bawden, Abi Spicer, Noura Darwish, Amelie Goyer, Leonie Egli, Natacha Rupp, Kaori Minehira, Penny Gowland, Denis Breuille, Ian A. Macdonald, Elizabeth J. Simpson
Summary: This study aimed to investigate the changes in liver glycogen concentration in children after overnight fasting and its response to feeding. The study found that liver glycogen concentration decreased by 22.9% after overnight fasting, and the incremental response to consumption of 15.5g and 31g carbohydrates was higher compared to water.
AMERICAN JOURNAL OF CLINICAL NUTRITION
(2023)
Article
Biochemistry & Molecular Biology
Erin M. Lloyd, Gavin J. Pinniger, Miranda D. Grounds, Robyn M. Murphy
Summary: Dysferlinopathies are muscular dystrophies caused by a genetic deficiency of dysferlin protein, which leads to muscle wasting, inflammation, droplet accumulation, and adipose tissue replacement. This study found that dysferlin deficiency affects the function of skeletal muscles, as well as the abundance of proteins related to calcium handling and glucose/glycogen metabolism.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Genetics & Heredity
Philip J. Hennis, Elaine Murphy, Rick Meijer, Robin H. Lachmann, Radha Ramachandran, Claire Bordoli, Gurinder Rayat, David J. Tomlinson
Summary: Individuals with GSD IIIa have lower peak oxygen uptake and knee extension strength than predicted values. Patients with higher physical capacity exhibit superior muscle size, structure characteristics, and higher health-related quality of life. This study provides normative values for important markers of physical capacity.
ORPHANET JOURNAL OF RARE DISEASES
(2022)
Article
Physiology
Natalie R. Janzen, Jamie Whitfield, Lisa Murray-Segal, Bruce E. Kemp, John A. Hawley, Nolan J. Hoffman
Summary: Disrupting AMPK-glycogen interaction reduces maximal exercise capacity and skeletal muscle AMPK alpha and beta 2 content, and increases glycogen utilization.
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Nutrition & Dietetics
Tomaz Mars, Katarina Mis, Marija Meznaric, Sonja Prpar Mihevc, Vid Jan, Fred Haugen, Boris Rogelj, Arild C. Rustan, G. Hege Thoresen, Sergej Pirkmajer, Natasa Nikolic
Summary: Both innervation and EPS promote differentiation into different fiber types in human myotubes, leading to a more oxidative phenotype in terms of metabolism.
APPLIED PHYSIOLOGY NUTRITION AND METABOLISM
(2021)
Article
Physiology
Elena Monti, Luana Toniolo, Lorenzo Marcucci, Michela Bondi, Ivan Martellato, Bostjan Simunic, Paolo Toninello, Martino V. Franchi, Marco V. Narici, Carlo Reggiani
Summary: The study indicates that muscle hypertrophy in body builders does not negatively impact force generation capacity, as increases in fiber size and force are proportional once the differential swelling response is accounted for.
Article
Multidisciplinary Sciences
Yoshitaka Mita, Haonan Zhu, Yasuro Furuichi, Hiroki Hamaguchi, Yasuko Manabe, Nobuharu L. Fujii
Summary: The ratio of muscle fiber types determines the properties of skeletal muscle tissue, and a myokine called Rspo3 has been found to determine whether satellite cells differentiate into type I fibers. Through induction experiments, it was found that Rspo3 significantly increases the expression of type I fibers, and this effect is mainly mediated through the Wnt/beta-catenin signaling pathway.
SCIENTIFIC REPORTS
(2022)
Article
Neurosciences
Jeppe F. Vigh-Larsen, Niels Ortenblad, Ole Emil Andersen, Hallur Thorsteinsson, Thea H. Kristiansen, Stine Bilde, Mads S. Mikkelsen, Joachim Nielsen, Magni Mohr, Kristian Overgaard
Summary: The study revealed a fiber type- and localization-specific glycogen utilization during high-intensity intermittent exercise, which changes over time. The breakdown rate of glycogen in type 2 fibers was higher than type 1 fibers, and there was significant heterogeneity in single-fiber glycogen utilization.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Article
Biochemistry & Molecular Biology
Takashi Yamada, Iori Kimura, Yuki Ashida, Katsuyuki Tamai, Hiroyori Fusagawa, Noritsugu Tohse, Hakan Westerblad, Daniel C. Andersson, Tatsuya Sato
Summary: Interval training with high-intensity contractions improves fatigue resistance in skeletal muscle by increasing mitochondrial function, specifically through increased expression of mitochondrial respiratory chain complexes.
Article
Neurosciences
Simeon P. Cairns, Jean-Marc Renaud
Summary: During repeated intense exercise, a decrease in muscle glycogen content and disturbances in potassium (K+) concentration across muscle membranes occur simultaneously, contributing to skeletal muscle fatigue. This study aimed to investigate the interaction between elevated extracellular K+ concentration and reduced glycogen on force production. The results showed that severe depletion of glycogen led to a significant decline in force production, and the decline was exacerbated at elevated extracellular K+ concentration. Additionally, the replenishment of glucose increased both glycogen content and force production. These findings provide direct evidence of the synergistic interaction between elevated extracellular K+ concentration and reduced muscle glycogen, which may contribute to muscle fatigue by shifting the resting-force relationship towards a more negative resting membrane potential.
JOURNAL OF PHYSIOLOGY-LONDON
(2023)
Article
Endocrinology & Metabolism
Rodrigo Canibano-Fraile, Laurike Harlaar, Carlos A. dos Santos, Marianne Hoogeveen-Westerveld, Jeroen A. A. Demmers, Tim Snijders, Philip Lijnzaad, Robert M. Verdijk, Nadine A. M. E. van der Beek, Pieter A. van Doorn, Ans T. van der Ploeg, Esther Brusse, W. W. M. Pim Pijnappel, Gerben J. Schaaf
Summary: Pompe disease is an inherited metabolic myopathy characterized by lysosomal glycogen accumulation caused by deficiency of acid alpha-glucosidase (GAA). This study found elevated protein levels of enzymes involved in glucose uptake and cytoplasmic glycogen synthesis in skeletal muscle of Pompe disease mice and patients. These metabolic changes occur before muscle wasting and may aggravate the disease phenotype.
JOURNAL OF INHERITED METABOLIC DISEASE
(2023)
Article
Nutrition & Dietetics
Yutaka Matsunaga, Kenya Takahashi, Yumiko Takahashi, Hideo Hatta
Summary: The study found that ingesting a large amount of glucose immediately after exercise increased insulin secretion and enhanced muscle glycogen recovery, whereas frequent and small amounts of glucose intake was shown to enhance liver glycogen recovery.
JOURNAL OF THE INTERNATIONAL SOCIETY OF SPORTS NUTRITION
(2021)
Article
Engineering, Biomedical
Nicklas Junge, Jean-Benoit Morin, Lars Nybo
Summary: Ballistic actions are crucial for generating power in sports where performance depends on contraction and movement velocities. Force-velocity-power profiling provides information about neuromuscular capabilities and vertical performance but is not well-studied in relation to horizontal movements. This study analyzed the associations between (FvP) over bar profiling and uni- and multidirectional ballistic performance tasks in high-level athletes.
SPORTS BIOMECHANICS
(2023)
Article
Sport Sciences
Svein Barene, Peter Krustrup, Andreas Holtermann
Summary: This study demonstrates that two to three weekly Zumba sessions can prevent sick leave and improve the total score of the Work Role Functioning Questionnaire (WRFQ) among female hospital employees.
EUROPEAN JOURNAL OF SPORT SCIENCE
(2023)
Article
Sport Sciences
Magni Mohr, Georgios Ermidis, Athanasios Z. Jamurtas, Jeppe F. Vigh-larsen, Athanasios Poulios, Dimitrios Draganidis, Konstantinos Papanikolaou, Panagiotis Tsimeas, Dimitrios Batsilas, Georgios Loules, Alexios Batrakoulis, Apostolos Sovatzidis, Jakob L. Nielsen, Theofanis Tzatzakis, Charikleia K. Deli, Lars Nybo, Peter Krustrup, Ioannis G. Fatouros
Summary: This study evaluated the effects of extended match time on physiological responses and fatigue in male soccer players. The results showed that there was a decrease in high-intensity running and intense accelerations and decelerations during extra time compared to normal time. Peak sprint speed, postmatch repeated sprint ability, and countermovement jump performance were also impaired after extra time. Muscle glycogen depletion, reductions in blood glucose levels, and hyperammonemia were identified as contributing factors to the increased fatigue during extended match play.
MEDICINE & SCIENCE IN SPORTS & EXERCISE
(2023)
Article
Sport Sciences
Esben Elholm Madsen, Peter Krustrup, Tina Hansen, Charlotte Sandager Aggestrup, Nikos Ntoumanis, Carsten Hvid Larsen, Kristina Pfeffer, Andreas Ivarsson, Knud Ryom, Malte Nejst Larsen, Mads Madsen, Jeppe Elholm Madsen, Anne-Marie Elbe
Summary: The 11 for Health in Denmark program has positive effects on the physiological and psychological health of 10-12-year-old schoolchildren. However, the motivational processes behind participation and behavioral changes have not been examined. This study found that the program increased intentions to participate in physical activity outside of school, providing evidence for a motivational link between in-school and out-of-school activities.
SCANDINAVIAN JOURNAL OF MEDICINE & SCIENCE IN SPORTS
(2023)
Article
Cell Biology
Martin Eisemann de Almeida, Joachim Nielsen, Maria Houborg Petersen, Emil Kleis Wentorf, Niklas Bigum Pedersen, Kurt Jensen, Kurt Hojlund, Niels ortenblad
Summary: This study used quantitative transmission electron microscopy to analyze the morphology of lipid droplets and mitochondria in skeletal muscle cells. It found that excessive storage of large lipid droplets in patients with type 2 diabetes was improved after high-intensity interval training, making it more similar to the characteristics of non-diabetic individuals.
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
(2023)
Article
Sport Sciences
Emil Morsbol Marqversen, Peter Krustrup, Thomas Bull Andersen
Summary: The study aimed to examine the impact of altitude, temperature, air humidity, and gravitational pull on the scoring probability of football players during a direct free kick from 25 m. The theoretical displacement in goal crossing position was determined using adjusted models, and compared to the probability distribution of six professional players from a top Danish league. No significant changes in scoring probability were observed when adjusting for the environment of different historic FIFA or UEFA finals. However, significant changes were found when adjusting for the players' aim points or orientation of their probability distributions. In conclusion, changes in altitude or temperature can significantly affect the scoring probability of highly accurate players.
SPORTS ENGINEERING
(2023)
Article
Physiology
Christopher T. A. Lewis, Lee Tabrizian, Joachim Nielsen, Jenni Laitila, Thomas N. Beck, Mathilde S. Olsen, Marija M. Ognjanovic, Per Aagaard, Rune Hokken, Simon Laugesen, Arthur Ingersen, Jesper L. Andersen, Casper Soendenbroe, Jorn W. Helge, Flemming Dela, Steen Larsen, Ronni E. Sahl, Tue Romer, Mikkel T. Hansen, Jacob Frandsen, Charlotte Suetta, Julien Ochala
Summary: Lewis et al. investigated the influence of training status on relaxed myosin conformations and found that moderate physical activity leads to a shift in relaxed myosin conformation, resulting in reduced ATP consumption. Their study revealed that physical activity level and training type can influence resting skeletal muscle myosin dynamics, suggesting that environmental stimuli such as exercise can rewire the molecular metabolism of human skeletal muscle through myosin.
JOURNAL OF GENERAL PHYSIOLOGY
(2023)
Article
Neurosciences
Javier Botella, Camilla T. Schytz, Thomas F. Pehrson, Rune Hokken, Simon Laugesen, Per Aagaard, Charlotte Suetta, Britt Christensen, Niels Ortenblad, Joachim Nielsen
Summary: This study investigated the mitochondrial structural characteristics in skeletal muscle of strength athletes compared to untrained controls. The results showed that strength athletes had increased mitochondrial cristae density, decreased mitochondrial size, and increased surface-to-volume ratio in their mitochondrial pool, despite similar mitochondrial volume density. In addition, resistance exercise led to mild mitochondrial stress but did not increase the number of damaged mitochondria. Moreover, the study found that acute resistance exercise increased the expression of markers of mitochondrial biogenesis, fission, and mitochondrial unfolded protein responses (UPRmt), and strength-trained individuals showed an enrichment of the UPRmt in their basal transcriptome. These findings suggest that strength athletes have a unique mitochondrial remodeling that minimizes the space required for mitochondria.
JOURNAL OF PHYSIOLOGY-LONDON
(2023)
Article
Neurosciences
Martin Eisemann de Almeida, Niels Ortenblad, Maria Houborg Petersen, Ann-Sofie Nybole Schjerning, Emil Kleis Wentorf, Kurt Jensen, Kurt Hojlund, Joachim Nielsen
Summary: Using transmission electron microscopy, we found that short-term exercise does not change the morphology, distribution, and contact between lipid droplets and mitochondria in skeletal muscle cells, but it does increase the contact between them. This effect is not affected by obesity or type 2 diabetes.
JOURNAL OF PHYSIOLOGY-LONDON
(2023)
Article
Sport Sciences
Camilla Tvede Schytz, Niels Ortenblad, Thor Andersen Birkholm, Peter Plomgaard, Lars Nybo, Kristoffer Jensen Kolnes, Ole Emil Andersen, Carsten Lundby, Joachim Nielsen, Kasper Degn Gejl
Summary: Manipulating dietary carbohydrates has an impact on muscle glycogen content and body mass, but does not affect short-term exercise performance. Adjusting pre-exercise glycogen levels can be an effective weight management strategy, especially for athletes involved in short-duration sports.
SCANDINAVIAN JOURNAL OF MEDICINE & SCIENCE IN SPORTS
(2023)
Article
Physiology
Morten B. Randers, Marie Hagman, Jesper F. Christensen, Susana Povoas, Jens Jung Nielsen, Peter Krustrup
Summary: The purpose of this study was to compare the effects of street football training and grass football training on the health and exercise performance of young men. The results showed that street football training improved submaximal exercise capacity, while grass football training had positive effects on submaximal exercise capacity and cardiorespiratory fitness.
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY
(2023)
Article
Sport Sciences
Ivone Carneiro, Peter Krustrup, Carlo Castagna, Rita Pereira, Niklas Rye Jorgensen, Eduardo Coelho, Susana Povoas
Summary: The study aimed to analyze the effects of different weekly exercise volumes on the bone health, body composition, and physical fitness of inactive middle-to-older-aged males. The results showed that the intervention groups that performed 2-3 weekly training sessions had the greatest improvements in bone health, body composition, and physical fitness.
EUROPEAN JOURNAL OF SPORT SCIENCE
(2023)
Article
Neurosciences
Camilla Tvede Schytz, Niels Ortenblad, Anne-Kristine Meinild Lundby, Robert Acton Jacobs, Joachim Nielsen, Carsten Lundby
Summary: Differences in oxidative phosphorylation between active and untrained individuals may be explained by higher mitochondrial volume and cristae density in active individuals, with no intrinsic mitochondrial respiratory capacity difference. There are no sex differences in mitochondrial volume and cristae density, oxidative phosphorylation, or normalized oxidative phosphorylation per muscle cristae surface area density.
JOURNAL OF PHYSIOLOGY-LONDON
(2023)