Michalis Nikolaidis
@mg-nikolaidis.bsky.social
Professor I Trying to speak my mind about the relevance of molecular processes in physiology and nutrition I Reviews Editor in Eur J Appl Physiol | https://nikolaidis.weebly.com/
Eric Trexler and Eric Helms devoted most of an episode of their podcast to our preprint on the energetic cost of building 1 kg of human skeletal muscle. They went through the assumptions one by one, then asked what the number might be good for. www.youtube.com/watch?v=ua2s...
Ep 387 - Energy Cost of Building Muscle
YouTube video by Iron Culture Podcast
youtube.com
1/13 How many calories does it take to build 1 kg of muscle? The question is straightforward but, as far as we can tell, it has not yet been answered quantitatively. www.biorxiv.org/content/10.6...
The Energetic Cost of Building Human Skeletal Muscle
The energetic cost of building human skeletal muscle has never been explicitly calculated or measured. We developed a quantitative bottom-up accounting model that integrates human skeletal-muscle comp...
biorxiv.org
When vitamin C levels are low, correcting them makes sense. But in this study, we found no evidence that each person needs a personalized vitamin C supplementation.
Nikos Margaritelis@margaritelis.bsky.social · 6mo agoHappy to share our publication in FRBM. We used aggregated sets of n-of-1 trials to study individual oxidative stress & inflammation responses to vit C supplementation. Huge thanks to @lorenzololli.bsky.social @gregatki.bsky.social @mg-nikolaidis.bsky.social www.sciencedirect.com/science/arti...
ICYMI: ONLINE NOW: Science captured by storytelling: the oxidative stress narrative
Science captured by storytelling: the oxidative stress narrative
The oxidative stress paradigm stands as a textbook example of how a simplified, early, and appealing scientific concept can become canonized and then resist revision. What began as a plausible heuristic about oxidative stress evolved into a research agenda and a pervasive cultural script.
dlvr.it
Is “oxidative stress” a useful concept in biology and medicine? In this work, led by Nikos, we argue that the term “oxidative stress” is devoid of biological meaning and, even worse, misleading.
Nikos Margaritelis@margaritelis.bsky.social · last yr.Our new paper with @mg-nikolaidis.bsky.social out in @cp-trendsmolecmed.bsky.social “Science captured by storytelling: the oxidative stress narrative” DOI: authors.elsevier.com/a/1lt2w5Eb1B...
Meta-research in muscle science: an audacious study shows glycerol storage, used for >60 years, makes fibers stiffer. Other biochemical effects? An important finding that may force a reexamination of past studies and influence the design of new ones. rupress.org/jgp/article/...
Glycerol storage increases passive stiffness of muscle fibers through effects on titin extensibility | Journal of General Physiology | Rockefeller University Press
To store and preserve muscle function, glycerol is often used, but its effect on passive properties is unclear. Muscles stored in glycerol showed increased
rupress.org
How much researchers truly believe what they are saying (from most to least): 1. Conference chat after some beers 2. Conference presentation 3. Paper (first draft) 4. Paper (published) 5. Grant proposal 6. Interview to media 😅
My understanding is that increases in blood reactive species or ox. stress markers cannot, predominantly, originate from ox. stress in tissues, since neither reactive species nor ox. stress products generated in cells have been shown to exit tissues & contribute to blood levels.
A fresh perspective on hydrogen peroxide metabolism during exercise. In vivo (normoxic), muscle contractions typically cause only minimal increases in H₂O₂ (<10%), whereas in vitro (hyperoxic) assays often show far greater increases (~150–340%). sciencedirect.com/science/arti...
State of the art in vivo reactive oxygen species measurements in skeletal muscle using fluorescent proteins
Evaluation of the effects of muscle contractions on reactive oxygen species (ROS) concentrations and their intracellular and intraorganelle dynamics i…
sciencedirect.com
Erythrocyte glutathione synthesis peaks at ~1.0 g protein/kg/day in young & old individuals, even though glutathione concentrations remain unchanged. Additional protein offers no benefit for those with "normal" glutathione levels. ajcn.nutrition.org/article/S000... ajcn.nutrition.org/article/S000...
Protein intake affects erythrocyte glutathione synthesis in young healthy adults in a repeated-measures trial
In 2005, the Institute of Medicine advised using methods other than nitrogen balance (NB) for determining protein requirements. Since then, protein requirements using indicator amino acid oxidation (I...
ajcn.nutrition.org
Much of the joy of computational papers lies in how they bring scattered insights together. Even if you don’t model, this one helps experimentalists design better studies by clarifying how training stresses drive specific adaptations across energy systems. arxiv.org/abs/2503.14841
The three-dimensional impulse-response model: Modeling the training process in accordance with energy system-specific adaptation
Athletic training is characterized by physiological systems responding to repeated exercise-induced stress, resulting in gradual alterations in the functional properties of these systems. The adaptive...
arxiv.org
Vitamin C+E supplementation blunts molecular adaptations to sprint interval training but not performance gains. Since performance wasn’t impaired, I wonder whether, and to what extent, the blunted molecular responses can truly be considered detrimental physoc.onlinelibrary.wiley.com/doi/10.1113/...
Antioxidant supplementation blunts the proteome response to 3 weeks of sprint interval training preferentially in human type 2 muscle fibres
Abstract figure legend Sprint interval training (SIT) is a popular time-efficient type of endurance training. Healthy young men performed nine SIT sessions (4–6 × 30 s all-out cycling sprints) over 3...
physoc.onlinelibrary.wiley.com
James Imlay turns redox chaos into clockwork: his new paper shows how membrane permeability sets the tempo of oxidative stress, with straight-up back-of-the-envelope math in the appendix. Fundamental, elegant, causal. onlinelibrary.wiley.com/doi/10.1111/...
The Barrier Properties of Biological Membranes Dictate How Cells Experience Oxidative Stress
Molecular oxygen diffuses across membranes with such speed that, despite respiration, the intracellular oxygen concentration does not differ significantly from that outside the cell. In contrast, mem...
onlinelibrary.wiley.com
Despite the challenges, this well-conducted study found that chronic Theracurmin—a bioavailable curcumin extract—supplementation neither enhanced nor impaired muscle hypertrophy in mice, but simply modulated some inflammatory and oxidative stress markers. journals.humankinetics.com/view/journal...
journals.humankinetics.com
Eur J Appl Physiol now welcomes reviews from all thinkers—whether or not they identify as physiologists. A great review is not about labels but about curiosity, depth & synthesis. Young scientists, your fresh takes are especially invited. More in my editorial: link.springer.com/article/10.1...
Review papers that push the boundaries of physiology and EJAP - European Journal of Applied Physiology
European Journal of Applied Physiology -
link.springer.com
Study shows that chronic antioxidant supplementation (VitC+VitE) blunted molecular adaptations to training, yet, no impact on any measure of exercise performance—considering that "antioxidant" is a vague term and that VitC+VitE may not always act as such. www.biorxiv.org/content/10.1...
biorxiv.org
Important study highlighting plausible molecular links between redox metabolism and exercise performance—an area notoriously difficult to dissect. The findings challenge assumptions that G6PD deficiency decreases exercise performance. A human replication study would be invaluable.
Angelo D’Alessandro@dalessandrolab.bsky.social · 2y agoG6PD deficiency affects 6% of humankind, predisposing RBCs to hemolysis after oxidant stress. Unexpectedly, humanized G6PD deficient mice do not hemolyze after oxidant stress post exercise, and tolerate exercise better! On the cover of @bloodadvances.bsky.social ashpublications.org/bloodadvance...
Our contribution to the Special Issue "Unlocking Athletic Potential: Exploring Exercise Physiology from Mechanisms to Performance" in FRBM, Guest-edited by Prof. Gomez-Cabrera & @c-handschin.bsky.social #redox #supplements #sports #evidence
Christoph Handschin@c-handschin.bsky.social · 2y ago“Evidence-based sports supplements: A redox analysis” by @margaritelis.bsky.social, @parikki.bsky.social, @mg-nikolaidis.bsky.social and colleagues. www.sciencedirect.com/science/arti... 10/17
A special issue on Exercise Physiology and Redox Biology, with bridges built along the way. Thanks for the kind invitation.
Christoph Handschin@c-handschin.bsky.social · 2y ago“Unlocking Athletic Potential: Exploring Exercise Physiology from Mechanisms to Performance” in FRBM is complete! Reviews on exercise physiology, muscle plasticity, molecular mechanisms and more! All #openaccess! #myoblue #muscle #exercise www.sciencedirect.com/special-issu... A long🧵: 1/17
If you are measuring total protein content in skeletal muscle and wondering about the origin of the often-cited 'holy number'—that ~20% of muscle is protein—a recent detailed study provides support for it, reporting a value of 17.7%. journals.physiology.org/doi/full/10....
Human adipose and skeletal muscle tissue DNA, RNA, and protein content | Journal of Applied Physiology
The purpose of this project was to provide a profile of DNA, RNA, and protein content in adipose tissue, which is relatively understudied in humans, to gain more insight into the amount of tissue that...
journals.physiology.org
I believe that a great issue stemming from the undeniable ergogenic potential of carbohydrates and creatine is the misconception that increasing any 'good' molecule in our body will automatically enhance exercise performance—and the reverse.
Remarkable study in mice provides invaluable insights but occasionally falls into the pitfall of overcomparing its findings to human studies, despite being unfeasible in humans. Plus a nuanced review of exercise metabolism, rich with intricacies for researchers. www.sciencedirect.com/science/arti...
Quantification of nutrient fluxes during acute exercise in mice
Despite the known metabolic benefits of exercise, an integrated metabolic understanding of exercise is lacking. Here, we use in vivo steady-state isot…
sciencedirect.com
Different concentrations of the reactive nitrogen species (RONS) nitrate and nitrite in trained vs untrained and healthy vs diseased groups, pointing to significant physiological implications.
Nikos Margaritelis@margaritelis.bsky.social · 2y agoMeta reports plasma [NO3−] (μmol/L) & [NO2−] (nmol/L): - at cardiometabolic risk 21.2 [95%CI, 13.4–29.0] & 122.8 [95%CI, 75.3–138.9] - health 33.9 [95%CI, 29.9–37.9] & 159.5 [95%CI, 131.8–187.1] - trained 43.0 [95%CI, 13.2–72.9] & 199.3 [95%CI, 117.6–281] www.sciencedirect.com/science/arti...
Free radicals and antioxidants: appealing to magic Our short paper argues that molecules cannot be classified as good or evil. Limited evidence supporting the consumption of antioxidants or superfoods and such interventions risk disrupting fundamental redox processes. www.cell.com/trends/endoc...
Free radicals and antioxidants: appealing to magic
In biology, there are no good or evil molecules. There is limited or no evidence to support the consumption of antioxidants or (super)foods rich in antioxidants, for the intended purpose of an antioxi...
cell.com
Sabine Hossenfelder and Professor Dave Explains are, in my view, both serious and thoughtful science communicators. Recently, Sabine shared her perspective on why academia is failing: www.youtube.com/watch?v=LKiB...
My dream died, and now I'm here
YouTube video by Sabine Hossenfelder
youtube.com
Impressive paper by Rob Phillips exploring physical biology through a historical lens: www.cell.com/current-biol...
Seeing with an extra sense
In this Guest editorial for the special issue, Rob Phillips considers some of the ways in which viewing the living through a physical lens allows us to see things that might otherwise remain hidden.
cell.com
