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Michalis Nikolaidis

@mg-nikolaidis.bsky.social

150 followers 180 following 33 posts

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/

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Nov 25

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...

www.cell.com

6 12

Reposted by Michalis Nikolaidis

Trends in Molecular Medicine @cp-trendsmolecmed.bsky.social · 7d

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

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · 5d

We believe that responsibility for perpetuating this appealing yet unfounded narrative lies with both scientists and society.

Michalis Nikolaidis @mg-nikolaidis.bsky.social · 5d

“Oxidative stress” has served as a supposed “biological mechanism” to justify antioxidant use in virtually every disease. Yet, supplements or “superfoods” have shown no proven benefits for health or exercise performance.

Michalis Nikolaidis @mg-nikolaidis.bsky.social · 5d

For various reasons, the narrative has prevailed that free radicals are “bad”, antioxidants are “good”, and that almost all diseases as well as exercise fatigue are caused (at least in part) by “oxidative stress.”

Michalis Nikolaidis @mg-nikolaidis.bsky.social · 5d

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 · 7d

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...

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Aug 8

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

Michalis Nikolaidis @mg-nikolaidis.bsky.social · Aug 5

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
😅

Michalis Nikolaidis @mg-nikolaidis.bsky.social · Jul 11

Relevant references:
pubmed.ncbi.nlm.nih.gov/32130885/
pubmed.ncbi.nlm.nih.gov/7614720/
www.sciencedirect.com/science/arti...

Blood as a reactive species generator and redox status regulator during exercise

The exact origin of reactive species and oxidative damage detected in blood is largely unknown. Blood interacts with all organs and tissues and, conse…

www.sciencedirect.com

Michalis Nikolaidis @mg-nikolaidis.bsky.social · Jul 11

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.

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Jul 10

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

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Jul 8

I didn’t know this, interesting angle, Angelo. It would be worth probing whether GSH flux is co-regulated with erythropoiesis or hemoglobin turnover, especially given the shared glycine precursor and the link between hemoglobin cysteines and GSH.

Michalis Nikolaidis @mg-nikolaidis.bsky.social · Jul 7

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

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Jun 5

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

Michalis Nikolaidis @mg-nikolaidis.bsky.social · May 29

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

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Apr 23

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

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Apr 15

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

Michalis Nikolaidis @mg-nikolaidis.bsky.social · Apr 4

If you have a review ready, submit it. If you have an idea, fill out our proposal template and send it to us for consideration. There are no any restrictions.

While science often rewards those who produce results, true progress depends equally on those who make sense of them.

Michalis Nikolaidis @mg-nikolaidis.bsky.social · Apr 4

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

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Feb 12

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...

www.biorxiv.org

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Jan 31

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 · Jan 30

G6PD 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...

Increased exercise tolerance in humanized G6PD-deficient mice

Key PointsG6PD-deficient mice maintain higher exercise speeds without increased red blood cell hemolysis, questioning assumed risks.Increased cardiac outpu

ashpublications.org

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Reposted by Michalis Nikolaidis

Nikos Margaritelis @margaritelis.bsky.social · Jan 30

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 · Jan 30

“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

Evidence-based sports supplements: A redox analysis

Despite the overwhelming number of sports supplements on the market, only seven are currently recognized as effective. Biological functions are largel…

www.sciencedirect.com

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Michalis Nikolaidis @mg-nikolaidis.bsky.social · Jan 30

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 · Jan 30

“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

Free Radical Biology and Medicine | Unlocking Athletic Potential: Exploring Exercise Physiology from Mechanisms to Performance | ScienceDirect.com by ElsevierScienceDirect

Exercise training involves repeated exposure to increases in metabolic, thermal, mechanical, and oxidative stress. This exposure stimulates physiological adaptations that improve tolerance to similar ...

www.sciencedirect.com

Michalis Nikolaidis @mg-nikolaidis.bsky.social · Jan 6

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

Michalis Nikolaidis @mg-nikolaidis.bsky.social · Dec 16

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.

Michalis Nikolaidis @mg-nikolaidis.bsky.social · Dec 10

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…