We wrote about the potential reasons why some people respond less to training and about new highlights in resistance training research presented in November 2026. But we also criticize the concept of individual variation in exercise adaptations and suggest new study designs.

Great team involved in this review based on a conference we organized at the University of Jyväskylä, Finland. @uniofjyvaskyla.bsky.social tinyurl.com/27zupuhc @abigailmackey1.bsky.social @mackinprof.bsky.social @wimderave.bsky.social and others not yet in Bluesky.

Research into Resistance Training Response Heterogeneity: a Summary of the 2025 Conference at the University of Jyväskylä | Journal of Applied Physiology | American Physiological Society

The Inter-Individual Variation in Resistance Training Response Conference was hosted at the University of Jyväskylä, Finland November 19-21, 2025. This paper summarizes key themes that emerged across lectures and discussions. First, resistance training induces multi-dimensional adaptations at the tissue, muscle fiber, and ultrastructural levels, including radial muscle fiber hypertrophy through increased myofibril number, longitudinal growth through sarcomere addition throughout the length (not ends) of muscle fibers, and metabolic adaptations that emulate other models of rapid cell growth. Second, training program variables including weekly sets, volume-load, rest interval duration, and training proximity to failure meaningfully influence hypertrophic outcomes in the general population, whereas exercise selection can be flexible. Third, age as well as molecular signatures prior to and in response to training influence inter-individual response heterogeneity. Finally, while inter-individual variability in observed hypertrophic responses is considerable, delineating true inter-individual variability from random variation remains challenging. Hence, study design considerations that can be thoughtfully applied to enhance rigor include repeat validation trials, unilateral within-subject designs, minimum clinically important difference thresholds, and multivariate composite responder classifications. This paper aims to summarize conference highlights while also providing meaningful implications for both researchers and practitioners and advancing current thinking on heterogeneity in the resistance training response.

tinyurl.com

just got knocked over by this new paper from the Andrei Chagin lab: www.science.org/doi/epdf/10.... physically dropped the paper in delighted surprise when I got to the second half of Fig 5:

💪new 1st author publication @grithhojfeldt.bsky.social and Joris Michaud from fantastic #CollaborativeScience team effort bewteen @ismcopenhagen.bsky.social and Nestle @feigelab.bsky.social on the role of NAM/PN in human muscle regeneration🙌🏃🙌 advanced.onlinelibrary.wiley.com/doi/10.1002/...

Nicotinamide and Pyridoxine Supplementation Enhances Muscle Stem Cell Activity and Muscle Regeneration in Humans: A Randomized Placebo‐Controlled Clinical Trial of High Force Eccentric Contraction Rec...

In a randomized clinical trial, we test the potential of combined nicotinamide (NAM) and pyridoxine (PN) to improve muscle recovery through muscle stem cell (MuSC) activity. Daily oral NAM and PN sup....

advanced.onlinelibrary.wiley.com

We are hiring a POSTDOC on an NIH award to measure inertial effects of (in)active muscle. Please share and re-post widely! Please send expressions of interest to my UML email.

We’re now on LinkedIn! Check us out and follow us there! www.linkedin.com/feed/update/...

#muscle #geriatricresearch #exercise | Institute of Sports Medicine Copenhagen (ISMC)

New year, new location for our Thursday morning Department meetings in the Fælleshuset! And posting this on our new LinkedIn page! We were delighted to be joined by Kristian Villars Lolck from the Ge...

linkedin.com

We wrote this letter to address the overly rigid preregistration requirements imposed now by many journals on exploratory experimental physiology research - time to align guidelines with contemporary research methods! @ismcopenhagen.bsky.social @proferichter.bsky.social doi.org/10.1113/EP09...

Prespecified analysis plans are not suitable for exploratory experimental physiology research

Click on the article title to read more.

doi.org

"Prespecified analysis plans are not suitable for exploratory experimental physiology research" physoc.onlinelibrary.wiley.com/doi/10.1113/... @abigailmackey1.bsky.social

Prespecified analysis plans are not suitable for exploratory experimental physiology research

Click on the article title to read more.

physoc.onlinelibrary.wiley.com

🚨 We are hiring TWO postdocs to join the Cell Migration Lab (cellmig.org) 🇫🇮 as part of the new Centre of Excellence in Immune–Endothelial Interfaces (IMMENs). Join us to decode immune regulation & develop next-gen imaging tools! 🧪🔬 Details in thread 🧵👇 #ScienceSky #Postdoc #AcademicJobs Please RT🫶

CELL MIGRATION LAB

We study cell migration in health and disease

cellmig.org

3 factors can explain most of the variation in individual responses to HReT: measurement error, within-person biological variability, and true effect of the intervention 🙌Casper Soendenbroe for generating these data from another @ismcopenhagen.bsky.social study! journals.plos.org/plosone/arti...

Heavy resistance exercise training in older men: A responder and inter-individual variability analysis

Background The extent of inter-individual variability in response to heavy resistance exercise training (HReT), and the possible existence of non-responders, remains unclear. This study aimed to deter...

journals.plos.org

Big congrats to Max Ravn Merkel who successfully defended his PhD today on the topic of tendinopathy, backed by a strong team of supervisors and challenged by sharp opponents Profs Paul Ackermann 🇸🇪 and Jess Snedeker🇨🇭 🙌🥳🙌

Spinal motor neurons in dazzling detail. ✨ Each green dot is a spinal motor neuron - crucial but rare cells making up just 1% of neurons in the spinal cord. In diseases like ALS, they are selectively damaged, making them of special interest to neuroscientists. #neuroskyence #FluorescenceFriday

🚨This morning’s good news is that Max Merkel’s paper Increased Blood Flow and Tendon Swelling Precedes Vascular Expansion and Tissue Matrix Changes In Early Human Tendinopathy: A Potential Window for Superior Treatment Response is now online! 🥳🎅🎄 advanced.onlinelibrary.wiley.com/doi/10.1002/...

Increased Blood Flow and Tendon Swelling Precedes Vascular Expansion and Tissue Matrix Changes In Early Human Tendinopathy: A Potential Window for Superior Treatment Response

Human participants with early- or chronic-stage tendinopathy and healthy controls are investigated using ultrasound Doppler, 3T and 7T MRI, and tendon biopsies. Tendon swelling and hyperperfusion are....

advanced.onlinelibrary.wiley.com

💪🧠Thrilled to be awarded this grant to study how exercise supports the motoneurone-muscle interaction during ageing - with awesome collaborators @kevinmurachphd.bsky.social and Kristine Freude @ismcopenhagen.bsky.social 🙏@lundbeckfonden.bsky.social lundbeckfonden.com/en/exercise-...

Exercise to maintain and repair the ageing motoneurone-muscle axis

Has received a Professorship grant of DKK 20,000,000 from the Lundbeck Foundation.

lundbeckfonden.com

📣Latest from the PowerLab 🚨 journals.physiology.org/doi/abs/10.1... In this study we show that Eccentric overload training provided a more robust stimulus for longitudinal muscle remodelling than conventional resistance training.

Big Bones Mean Big Muscles: An MRI-Based Dataset of Muscle-Bone-Body Size Relationships Across 70 Human Muscles of the Upper Limb, Trunk, and Lower Limb journals.physiology.org/doi/abs/10.1...

Big Bones Mean Big Muscles: An MRI-Based Dataset of Muscle-Bone-Body Size Relationships Across 70 Human Muscles of the Upper Limb, Trunk, and Lower Limb | Journal of Applied Physiology | American Phys...

Body sizes and shapes vary widely, even among healthy adults, resulting in diverse muscle sizes, strengths, and performance capacities. This study developed an AI (artificially intelligent) algorithm ...

journals.physiology.org

Allison M. Owen et al. present this #TopicalReview examining therapeutic and pathological actions for fibro-adipogenic progenitors following #musculoskeletal injury 🏋️ 🔬 🔗 Read it here: physoc.onlinelibrary.wiley.com/doi/10.1113/...

This was a fun team effort with @grithhojfeldt.bsky.social Christian Hoegsbjerg, Arvind von Keudell👏 covering the full spectrum of human skeletal muscle regenerative capacity 💪 from sports🏃‍♀️to trauma 🏥 settings. Lots more work to do in this field! @ismcopenhagen.bsky.social

The Journal of Physiology@jphysiol.bsky.social · 8mo ago

This #TopicalReview by Grith Højfeldt et al. discusses the #repair capacity spectrum of human skeletal muscle injury from sports to surgical #trauma settings 🔎 💉 🔗 Read it here: physoc.onlinelibrary.wiley.com/doi/10.1113/...

Yesterday, Christian Couppé defended his doctorate of medical science (DMSc) investigating the Effects of Loading on Human Tendon in Health & Disease. Big thanks to the opponents Taija Finni & @larslandersen.bsky.social, chair Per Hölmich, & Jørn Wulff Helge for leading the ceremony 🥳 Congrats!

Two guest lecturers today! Håvard Visnes and Taija Finni give us new perspectives on the treatment of tendon ruptures, tendinopathy and ACL injuries.

In the snowy north❄️🇫🇮 today presenting our work on muscle memory in ageing and tissue injury, and learning about inter-individual variation🧠 Thank you Juha Ahtiainen and Mike Roberts for the invitation to this very interesting meeting🙏 Great to see old and new friends too🤗 @ismcopenhagen.bsky.social

Juha Hulmi@juhahulmi.bsky.social · last yr.

Conference: Inter-individual variation in exercise. Please join! The speakers are e.g. @mackinprof.bsky.social, @abigailmackey1.bsky.social, M Bamman, T Hornberger, M Roberts, B Schoenfeld, M Perola, G Nader, E Sillanpää, A Hecksteden, W Derave, P Atherton, J Ahtiainen and me. tinyurl.com/34xzsdss

Our review on all things muscle in CP is now published in Dev Med Child Neurology. Massive effort by Sebastian Edman with great support from Eva Ponten, Sudarshan Dayanidhi and @ferdinandvw.bsky.social onlinelibrary.wiley.com/doi/10.1111/...

Microscopic and molecular aspects of skeletal muscle alterations in cerebral palsy

Cerebral palsy, caused by non-progressive brain injury, is frequently accompanied by skeletal muscle alterations. This review synthesizes current evidence from muscle biopsy studies, revealing cellul...

onlinelibrary.wiley.com

New results presented at this morning's meeting by Birgitte Hougs Kjær from her impressive #PASEtrial testing treatment options for patients with chronic rotator cuff tendinopathy👏👏

Recruiting a comp PDRA for the lab 🚨 Working on multiple projects using integrated multi omics in bulk & single cell level Passion for data, coding, bioinformatics & keen to lead our labs comp workflow 12 months in first instance but extendable for further 19 months my.corehr.com/pls/coreport...

Day 2 of the Matrix Biology PhD course and we’re in the new Fælleshuset building starting our group work brain storming. Thanks to @douglaspdyer.bsky.social and @tranejoan.bsky.social for laying the foundations of ECM biology in yesterday’s lectures!

Upcoming Postdoc Position! With Chris Nelson’s lab at U of A, we are looking for a fully supported 2-year postdoc to work on muscle gene editing and detection of gene doping in vivo. If interested, email myself and Chris: kmurach@uark.edu and nelsonc@uark.edu #myoblue

New month, new mesh! 🕸️🍂October newsletter is out; Latest on career opportunities, publications, upcoming events, initiatives💥A spotlight interview with P. Rosales that explores how funding cuts affects researchers📝Plus our monthly poll🗳️

Top Cited Review Article: Mechanisms of mechanical overload-induced skeletal muscle hypertrophy: current understanding and future directions Michael D. Roberts, et al. https://ow.ly/moMh50Xe5nU #hypertrophy #myofiber

A heavy lift from a literal strongman, PhD candidate PJ Koopmans “The Age-Dependent Resident Myonuclear Multi-Omic Response to a Skeletal Muscle Hypertrophic Stimulus” 💪🏻 www.biorxiv.org/content/10.1...

Our tendon enthusiasts @ccstorytime.bsky.social & @annesofieagergaard.bsky.social are in Nanjing, China for an international meeting focused on orthopedic surgery and sports medicine talking about their approach with circadian rhythms and exercise-based treatment on tackling tendinopathy ⏰🏋️‍♀️ #tendon