Repeated Heat Stress Modulates the Levels of the Mitokines MOTS-C and FGF21 in Active Men during Calf Muscle Immobilization

What Was Tested

The paper reports a study of MOTS-c, published as a randomized controlled trial.

This study thus investigated the effect of repeated heat exposures on mitokine response in the context of immobilization-induced muscle atrophy.

Who Took Part

According to the abstract, 19 men were involved.

PubMed indexes the participants as young adults and adults, men only.

A total of 19 physically active men underwent 4 wk of supervised training followed by 2 wk of immobilization of the left ankle, during which they were randomly divided into the heat ( n = 9) or the sham ( n = 10) treatment group.

How the Study Was Run

In design terms this was a randomized study.

Random assignment meant chance, not the researchers, decided who got MOTS-c and who got the comparison, which limits bias.

Muscle thickness by ultrasound, cross-sectional area by magnetic resonance imaging, circulating and skeletal muscle mitokine levels, and a series of skeletal muscle anabolism and atrophy markers were assessed before and after the 2-wk immobilization period.

What Was Measured

Topics PubMed links to this paper include Muscle, Skeletal, Immobilization, Fibroblast Growth Factors, Muscular Atrophy, Magnetic Resonance Imaging, Heat-Shock Response and Hot Temperature.

Author keywords: DISUSE MUSCLE ATROPHY, FGF21, HEAT STRESS, MITOKINES and MOTS-C.

What This Means in Plain Language

The paper is a randomized study of MOTS-c in 19 men.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

Results are reported in around 4 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 2025 (Medicine and science in sports and exercise), a journal based in United States.

More context: the MOTS-c compound page, all human trials.