Joachim Nielsen
@joachimnielsen.bsky.social
📤 311
📥 209
📝 52
Associate Professor in Muscle Physiology and Metabolism. University of Southern Denmark.
pinned post!
We are ready to scale up glycogen analysis using electron microscopy. By applying a new AI-based image analysis pipeline, workload for 50 samples was reduced from ~600 hours to ~20 hours. This moves us beyond small-scale TEM studies. Details below 👇
2 months ago
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Joachim Nielsen
Juan C. Landoni
5 days ago
Our paper is now out in Science! Super excited to share our discovery that
#mitochondria
#pearling
is the elusive mechanism driving the regular distribution and inheritance of
#mtDNA
nucleoids 🧬 [1/6]
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Stress-Encoded Mitochondrial Plasticity: ATF4 Control of Mega-Mitochondria and Nanotunnel Communication
www.biorxiv.org/content/10.6...
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https://www.biorxiv.org/content/10.64898/2026.03.04.709625v2
6 days ago
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Insulin-independent glucose uptake in skeletal muscle by coupled SGLT and Na,K-ATPase transport
www.biorxiv.org/content/10.6...
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https://www.biorxiv.org/content/10.64898/2026.03.24.714065v1
6 days ago
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Adrβ2 in skeletal muscle cells is required for exercise-induced Pgc1α but not for metabolic benefits of exercise on diet-induced obesity
www.biorxiv.org/content/10.6...
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https://www.biorxiv.org/content/10.64898/2026.03.27.714812v1-0
6 days ago
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Joachim Nielsen
Izzy Jayasinghe
22 days ago
🚨New paper out today in
@acs.org
ACS Nano, showing how expansion microscopy can visually quantify the cell surface receptor turnover mediated by signalling & receptor organising machineries on the surfaces of endosomes, some of the smallest organelles in cells. 🧪 🔬 1/
pubs.acs.org/doi/10.1021/...
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Craig A. Goodman
26 days ago
Deconvoluting fibre type proportions from human skeletal muscle transcriptomics and proteomics data using FibeRtypeR
physoc.onlinelibrary.wiley.com/doi/10.1113/...
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Deconvoluting fibre type proportions from human skeletal muscle transcriptomics and proteomics data using FibeRtypeR
Abstract figure legend FibeRtypeR infers fibre type composition from bulk muscle transcriptome or proteome datasets based on single-fibre transcriptome and proteome profiles as reference datasets for...
https://physoc.onlinelibrary.wiley.com/doi/10.1113/JP290082
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Joachim Nielsen
Adam J Rose
29 days ago
Proud to share our latest findings: A nutrient-hormone axis pivots an energy trade-off between resting thermogenesis and movement expenditure
www.sciencedirect.com/science/arti...
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A nutrient-hormone axis pivots an energy trade-off between resting thermogenesis and movement expenditure
The biological reason why mammals increase daily energy expenditure when consuming a protein-dilute diet is currently enigmatic. Recognizing that body…
https://www.sciencedirect.com/science/article/pii/S2095254626000104?via%3Dihub
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Mitochondrial cristae density is trainable in human skeletal muscle
rdcu.be/e7pc5
Thanks to the reviewers and
@diabetologiajnl.bsky.social
for the constructive feedback and for publishing our work. Thread below:
add a skeleton here at some point
about 1 month ago
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Low-dose lithium, oestrogen deficiency and the sarcoplasmic reticulum: Are they connected
onlinelibrary.wiley.com/share/author...
Low-dose lithium supplementation promotes musculoskeletal and metabolic health in ovariectomized female mice
physoc.onlinelibrary.wiley.com/share/IMJBJH...
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https://physoc.onlinelibrary.wiley.com/share/IMJBJHHDPYFVKUKJJ9IW?target=10.1113/JP289990
about 1 month ago
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Joachim Nielsen
Craig A. Goodman
about 1 month ago
A network-based atlas of human skeletal muscle aging
www.medrxiv.org/content/10.6...
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A network-based atlas of human skeletal muscle aging
Skeletal muscle metabolic and physical capacities are influenced by both genetics and load status and decline with age. Recent advances in sequencing have detailed cell types at unprecedented detail; ...
https://www.medrxiv.org/content/10.64898/2026.02.15.26346348v1
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Joachim Nielsen
Julien Ochala
about 2 months ago
Our new project unveiling an integrative single-fiber framework that connect multi-omic cellular heterogeneity to molecular function in ICU-related muscle wasting! Congratulations to all authors especially Alexandra who led the whole project! Thank you to
@lundbeckfonden.bsky.social
for the support
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https://www.biorxiv.org/content/10.64898/2026.02.16.706099v1
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Joachim Nielsen
Thomas Elbenhardt Jensen
about 2 months ago
Our latest work showing that GLUT4 exofacial antibodies can measure translocation in humans and rodent skeletal muscle fibers and is impaired in TBC1D4 KO rats despite rescued GLUT4 expression. Congrats Kaspar and co-authors. DM me for open access version:
diabetesjournals.org/diabetes/art...
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Exofacial Epitope–Specific Antibodies Detect GLUT4 Translocation in Adult Human, Rat, and Mouse Skeletal Muscle
Skeletal muscle glucose transporter 4 (GLUT4) translocation to the plasma membrane determines glucose uptake in response to insulin and exercise and is dis
https://diabetesjournals.org/diabetes/article-abstract/doi/10.2337/db25-0567/164431/Exofacial-Epitope-Specific-Antibodies-Detect-GLUT4?redirectedFrom=fulltext
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doi.org/10.1113/JP28...
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Dynamic balance of myoplasmic energetics, redox state and protons in a fast‐twitch oxidative glycolytic skeletal muscle fibre
Abstract figure legend We have developed a computational model of energy metabolism in fast-twitch oxidative glycolytic muscle fibres. The model considers thermodynamically constrained enzyme kinetic....
https://doi.org/10.1113/JP289702
about 2 months ago
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Beha GH, Stemmerik MG, Boer VO, et al. Quantification of muscle glycogen distribution in Pompe disease using 7 Tesla 13C NMR spectroscopy
jnnp.bmj.com/content/97/3...
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Quantification of muscle glycogen distribution in Pompe disease using 7 Tesla 13C NMR spectroscopy
Background Late-onset Pompe disease has a characteristic pattern of fat replacement and wasting of especially axial and hamstring muscles. This characteristic pattern of muscle degeneration is still t...
https://jnnp.bmj.com/content/97/3/201
about 2 months ago
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We are ready to scale up glycogen analysis using electron microscopy. By applying a new AI-based image analysis pipeline, workload for 50 samples was reduced from ~600 hours to ~20 hours. This moves us beyond small-scale TEM studies. Details below 👇
2 months ago
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faseb.onlinelibrary.wiley.com/share/KKBJBR...
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Strenuous Exercise Alters Brain Creatine and Glutamate/Glutamine (Glx) in Humans: Evidence From Dynamic 1H‐MRS and 1H‐MRSI
You have to enable JavaScript in your browser's settings in order to use the eReader.
https://faseb.onlinelibrary.wiley.com/share/KKBJBRSPNMIXZHBBEQXQ?target=10.1096/fj.202504543R
2 months ago
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Joachim Nielsen
Jason Cantor
3 months ago
For ~century, we’ve asked: why do proliferating cells ferment glucose even when O2 is around? I’m thrilled to share our latest work
@natmetabolism.nature.com
, led by
@thebiokimist.bsky.social
. By leveraging conditional essentiality in HPLM, we propose a provocative new answer to this classic Q. 🧵
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Christian Frezza
3 months ago
Mitochondrial contact site and cristae organizing system promotes modular assembly of cytochrome c oxidase: Cell Reports
www.cell.com/cell-reports...
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Mitochondrial contact site and cristae organizing system promotes modular assembly of cytochrome c oxidase
Colina-Tenorio et al. show that MICOS interacts with the Cox1 and Cox3 assembly modules and facilitates respiratory complex IV biogenesis. By recruiting assembly factors and the mitochondrial multifun...
https://www.cell.com/cell-reports/fulltext/S2211-1247%2825%2901499-8
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Joachim Nielsen
Matteo Fiorenza
4 months ago
📄 New preprint Using deep physiological and molecular phenotyping in individuals carrying a diabetogenic mtDNA mutation, we probe whether, which, and how mitochondrial defects drive insulin resistance in humans. 👇 Link in first comment
#Physiology
#Diabetes
#Mitochondria
#Metabolism
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Joachim Nielsen
Craig A. Goodman
4 months ago
Acute effects of resistance exercise on skeletal muscle glycogen depletion: A systematic review and meta-analysis
physoc.onlinelibrary.wiley.com/doi/10.14814...
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Acute effects of resistance exercise on skeletal muscle glycogen depletion: A systematic review and meta‐analysis
To compile and statistically summarize quantitative evidence on the acute effects of resistance training sessions on muscle glycogen concentration, a systematic search was conducted on Pubmed, Web of...
https://physoc.onlinelibrary.wiley.com/doi/10.14814/phy2.70683
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Joachim Nielsen
Sam Lewis, Ph.D.
4 months ago
⚡️Mitochondria make ATP, the energy that powers life. But in neurons, with axons up to a meter long, how do these tiny power plants stay functional in the right places? We went looking. 1/n
www.biorxiv.org/content/10.6...
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Self-renewal of neuronal mitochondria through asymmetric division
Mitochondrial ATP production is essential for life. Mitochondrial function depends on the spatio-temporal coordination of nuclear and mitochondrial genome expression, yet how this coordination occurs ...
https://www.biorxiv.org/content/10.64898/2025.12.17.694973v1
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"We find that when glycogen stores are present, they provide remarkable resilience to dopamine nerve terminal function under extreme hypometabolic conditions, but ... impairment of access to glycogen, makes them hypersensitive to fuel deprivation."
www.pnas.org/doi/suppl/10...
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Neuromodulatory control of energy reserves in dopaminergic neurons | PNAS
The brain is a metabolically vulnerable organ as neurons have both high resting metabolic rates and the need for local rapid conversion of carbon s...
https://www.pnas.org/doi/suppl/10.1073/pnas.2523019122
4 months ago
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Joachim Nielsen
eLife
4 months ago
This ‘fundamental’ study uncovers how directing pyruvate into mitochondria can shrink cells by shifting their metabolism away from building amino acids and proteins.
buff.ly/hFHjKy9
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Joachim Nielsen
5 months ago
Super happy to share our latest study on muscle remodeling in human cachexia in patients with lung cancer:
www.biorxiv.org/content/10.1...
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https://www.biorxiv.org/content/10.1101/2025.11.19.689342v2
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Joachim Nielsen
Michael Eisen
6 months ago
Finally, someone has solved a real problem with AI! No more having to take a paper in the format for a journal that rejected you, and reformat it for a new journal. Well done!!
formatmypaper.com
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Professor Adam P. Sharples
5 months ago
First post on Blue Sky New pre-print! Does muscle remember disuse muscle wasting? Our new study shows skeletal muscle retains a molecular memory of disuse! Young muscle shows transcriptional resilience to repeated atrophy. Aged muscle shows exaggerated susceptibility.
doi.org/10.1101/2025...
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Joachim Nielsen
Richard Sever
5 months ago
Excited to launch an openRxiv partnership with the scientist-run AI review service qed (
@qedscience.bsky.social
), the brainchild of
@odedrechavi.bsky.social
1/n
openrxiv.org/enabling-rev...
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Enabling options for review: from training and transparency to author-centered AI tools - openRxiv
Peer review is widely viewed as a critical aspect of biomedical communication. Ideally, it provides authors with feedback so they can improve manuscripts and gives readers, particularly nonspecialists...
https://openrxiv.org/enabling-review-options/
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Joachim Nielsen
Oded Rechavi
5 months ago
IT'S HAPPENING! 💥 I'm psyched to launch the collaboration between
@qedscience.bsky.social
&
@openrxiv.bsky.social
@biorxivpreprint.bsky.social
! Preprint + q.e.d = your science is out there, and anyone can appreciate it. Let's care about making discoveries, and not on “getting published” (1/3) 👇
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Joachim Nielsen
Paul Greenhaff
5 months ago
Hopefully of interest to scientists and exercise practitioners with and interest in muscle mass and functional gains in human volunteers.
doi.org/10.1113/JP28...
@jphysiol.bsky.social
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NSAID ingestion augments training‐induced muscle hypertrophy and differentially affects muscle mRNA expression, but not strength gains, in trained men
Abstract figure legend Schematic outlining the impact of NSAID ingestion on resistance exercise training-induced changes in muscle morphology, function and gene networks relative to placebo ingestion...
http://doi.org/10.1113/JP289542
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Joachim Nielsen
Nikolai Slavov
6 months ago
This article is a homecoming for me. As a PhD student, I focused on the growth-rate transcriptional regulation in yeast. Now, ~ 20 years later, we report protein regulation scaling with the growth rates of single cells in mammalian tissues.
www.biorxiv.org/content/10.1...
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Principles of protein abundance regulation across single cells in a mammalian tissue
Protein synthesis and clearance are major regulatory steps of gene expression, but their in vivo regulatory roles across the cells comprising complex tissues remains unexplored. Here, we systematicall...
https://www.biorxiv.org/content/10.1101/2025.09.17.676955v1.full
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Javier Gonzalez
6 months ago
Is Human Energy Expenditure Constrained? I recently debated Herman Pontzer on this topic in Shenzhen, China. My slides can be viewed here:
www.linkedin.com/posts/javier...
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RACMEM Debate: Is Human Energy Expenditure Constrained? | Javier Gonzalez
Is human energy expenditure constrained? This hypothesis was proposed by Herman Pontzer, and has received widespread interest with coverage from mainstream media, podcasts, and even the RI Christmas ...
https://www.linkedin.com/posts/javier-gonzalez-b61615106_racmem-debate-is-human-energy-expenditure-activity-7385648354019667968-7WEM?utm_source=share
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Joachim Nielsen
Chloé Yeung
6 months ago
Manuscript now accepted! 🥳
@steffendanielle.bsky.social
@valerioizzi.bsky.social
@abigailmackey1.bsky.social
@ismcopenhagen.bsky.social
Spatially distinct ECM-producing fibroblasts and myonuclei orchestrate early adaptation to mechanical loading in the human muscle-tendon unit
add a skeleton here at some point
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The Expanding Clinical and Genetic Spectrum of Muscle Glycogen Storage Disease 0, (GSD0B) - Donoghue - 2025 - American Journal of Medical Genetics Part A - Wiley Online Library
onlinelibrary.wiley.com/doi/10.1002/...
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The Expanding Clinical and Genetic Spectrum of Muscle Glycogen Storage Disease 0, (GSD0B)
Glycogen storage disorders are a group of genetic disorders affecting glucose homeostasis in the body. Muscular glycogen stores are essential for liberating glucose for energy supply during bursts of...
https://onlinelibrary.wiley.com/doi/10.1002/ajmg.a.64149
6 months ago
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Joachim Nielsen
Matthew Alexander, PhD
6 months ago
New
#scisignal
paper: Phosphorylation of RYR1 at Ser2902 decreases Ca2+ leak in skeletal muscle and susceptibility to malignant hyperthermia and heat stroke.
#Myoblue
tinyurl.com/bddss3j6
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Phosphorylation of RYR1 at Ser2902 decreases Ca2+ leak in skeletal muscle and susceptibility to malignant hyperthermia and heat stroke
Reducing Ca2+ leak through mutant RYR1 prevents pathological heat production in skeletal muscle.
https://tinyurl.com/bddss3j6
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Joachim Nielsen
Aydin Lab
6 months ago
Excited to share that our paper on mitochondrial cardiolipin dynamics is published in
@natcomms.nature.com
today! We provide molecular explanations for unique aspects of mitochondrial morphology and the mechanisms underlying cardiolipin-related Barth Syndrome.
www.nature.com/articles/s41...
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Cardiolipin dynamics promote membrane remodeling by mitochondrial OPA1 - Nature Communications
This study reveals how cardiolipin governs mitochondrial morphology by modulating the activity of human OPA1 and how its replacement by monolyso-cardiolipin, as observed in Barth syndrome, impacts mitochondrial membrane-shaping mechanisms.
https://www.nature.com/articles/s41467-025-63813-4
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Our new preprint! Great effort by Martin de Almeida and Amalie Platz has led to the discovery that training increases mitochondrial cristae density.
www.biorxiv.org/cgi/content/...
Thanks to Niels Ørtenblad at SDU and Kurt Højlund and Maria Petersen at Steno Diabetes Center Odense. 🧵 Thread below…
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Mitochondrial cristae density is increased following high-intensity interval training in patients with type 2 diabetes
Aims/hypothesis: Mitochondrial cristae architecture is a key determinant of oxidative capacity in skeletal muscle. While mitochondrial dysfunction is common in type 2 diabetes, it remains unclear whet...
https://www.biorxiv.org/cgi/content/short/2025.09.29.678437v1
6 months ago
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Joachim Nielsen
Sakamoto Lab
6 months ago
Check out our latest preprint from the lab, spearheaded by researcher
@itsmedipsikha.bsky.social
, investigating the distinctive roles of regulatory gamma subunits of the AMPK protein complex in small molecule activator-stimulated skeletal muscle glucose uptake.
www.biorxiv.org/content/10.1...
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Common and distinct roles of AMPKγ isoforms in small-molecule activator-stimulated glucose uptake in mouse skeletal muscle
Objective: Small-molecule activators targeting the allosteric drug and metabolite (ADaM) site of AMPK enhance insulin-independent glucose uptake in skeletal muscle and lower glucose in preclinical mod...
https://www.biorxiv.org/content/10.1101/2025.09.26.678768v1
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Electron tomography reveals mitochondrial network and cristae remodelling during cell differentiation in the human placenta
Mitochondria adapt their structure through fusion and fission, yet how their morphology and cristae architecture alter as cells differentiate remains unclear. The human placenta is an ideal model for ...
https://www.biorxiv.org/content/10.1101/2025.06.09.658204v1
6 months ago
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Joachim Nielsen
Experimental Physiology
6 months ago
Does biological sex impact the rate of intrinsic mitochondrial respiration in the presence of creatine in human skeletal muscle? Emily J. Ferguson (
@queensuresearch.bsky.social
) et al. investigate! 📜
buff.ly/46B6lzL
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Joachim Nielsen
bioRxiv Physiology
7 months ago
Mechanical Loading Induces the Longitudinal Growth of Muscle Fibers via an mTORC1-Independent Mechanism
https://www.biorxiv.org/content/10.1101/2025.09.19.676647v1
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Divergent Changes in Peak Fat Oxidation and Fatmax Following 3-Day Dietary Interventions Are Related to Muscle Glycogen Availability in Men by Tarry, Vestergaard, Petersen, Olsen, Ingersen, Connor, Pilegaard, Dela, Larsen, Shaw, and Helge
onlinelibrary.wiley.com/share/CDCGW2...
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Divergent Changes in Peak Fat Oxidation and Fatmax Following 3‐Day Dietary Interventions Are Related to Muscle Glycogen Availability in Men
You have to enable JavaScript in your browser's settings in order to use the eReader.
https://onlinelibrary.wiley.com/share/CDCGW27S23NJJ3TUWKU4?target=10.1111/sms.70132
7 months ago
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Joachim Nielsen
Nature Reviews Disease Primers
7 months ago
Sarcopenia is accelerated loss of skeletal muscle mass and function commonly, but not exclusively, associated with advancing age. It is observed across many species including humans in whom it can lead to decline in physical function and mobility.
https://www.nature.c...
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Joachim Nielsen
Craig A. Goodman
7 months ago
Congrats to Steffen Raun, Lykke Sylow and Team for their new Redox Biology paper, "Skeletal muscle Rac1 mediates exercise training adaptations towards muscle glycogen resynthesis and protein synthesis", that included the CMR's Prof Paul Gregorevic
www.sciencedirect.com/science/arti...
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Skeletal muscle Rac1 mediates exercise training adaptations towards muscle glycogen resynthesis and protein synthesis
Long-term exercise training elicits tremendous health benefits; however, the molecular understanding is incomplete and identifying therapeutic targets…
https://www.sciencedirect.com/science/article/pii/S221323172500357X
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Joachim Nielsen
Michele Zanini
7 months ago
🚨 The last paper of my PhD is out in @MSSE Regular Long Runs and Higher Training Volumes are Associated with Better Running Economy Durability in Performance Matched Well-Trained Male Runners 🙏🏻 Rich Blagrove & Jonathan Folland Temporary free download. 🔗
journals.lww.com/acsm-msse/ab...
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Elegant study on glycogen using the one-legged exercise model: Exercise- and diet-induced glycogen depletion impairs performance during one-legged constant-load, high-intensity exercise in humans Thomassen, McKenna, Olmedillas, Wyckelsma, Bangsbo, Nordsborg
www.frontiersin.org/journals/phy...
8 months ago
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Joachim Nielsen
Sakamoto Lab
8 months ago
Congratulations to Researcher
@itsmedipsikha.bsky.social
for being one of the recipients of the EFSD/Lilly Young Investigator Awards! We celebrated her achievement with some cakes and bubbles earlier 🥳
@easdnews.bsky.social
@cbmr.science
www.europeandiabetesfoundation.org/recipients/e...
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Join our PhD course in metabolism and EC coupling. November 10-15. University of Southern Denmark. Enrol here:
www.sdu.dk/en/forskning...
8 months ago
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Joachim Nielsen
Javier Gonzalez
8 months ago
New paper! Do ketone esters affect post-exercise recovery?
doi.org/10.1007/s003...
#ketones
#exercise
#sports
#nutrition
#recovery
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www.biorxiv.org/content/10.1...
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Glycogen metabolism in mouse embryonic Sertoli cells sustains the germ line through the lactate shuttle
Metabolites are key regulators of cell fate decisions, epigenetic remodeling, and lineage commitment. While genetic pathways governing testis differentiation are well studied, the role of metabolism r...
https://www.biorxiv.org/content/10.1101/2025.07.23.666216v1
8 months ago
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Joachim Nielsen
Kevin Murach
8 months ago
“Muscle memory theory: A critical evaluation” in @JPhysiol led by postdoc Nate Serrano
physoc.onlinelibrary.wiley.com/doi/10.1113/...
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Muscle memory theory: A critical evaluation
Click on the article title to read more.
https://physoc.onlinelibrary.wiley.com/doi/10.1113/JP289597
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