Evidence map›Paper›PMID 41719153›Full record

ArticleExperimental physiology2026

Exercise during 14 days of head down tilt bedrest attenuates motor unit impairments in older humans.

Philippe St-Martin, Jean-Christophe Lagacé, Mathil Ruel, Ahmed Ghachem, Guillaume Léonard, Eleonor Riesco, Mathew Piasecki, Jamie S McPhee, Isabelle J Dionne

Abstract read
In one paragraph

Article in Experimental physiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Philippe St-MartinFaculty of Physical Activity Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.ORCID https://orcid.org/0000-0001-9824-2072
Jean-Christophe LagacéFaculty of Physical Activity Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.ORCID https://orcid.org/0000-0001-9101-9900
Mathil RuelFaculty of Physical Activity Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.ORCID https://orcid.org/0009-0007-7105-3045
Ahmed GhachemFaculty of Physical Activity Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Guillaume LéonardResearch Centre on Aging, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Eleonor RiescoFaculty of Physical Activity Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.ORCID https://orcid.org/0000-0002-7804-4631
Mathew PiaseckiCentre of Metabolism, Ageing & Physiology (COMAP) Injury, Recovery & Inflammation Sciences, School of Medicine, NIHR Nottingham BRC, University of Nottingham, Royal Derby Hospital Centre, Derby, UK.
Jamie S McPheeDepartment of Sport and Exercise Sciences, Manchester Metropolitan University Institute of Sport, Manchester, UK.ORCID https://orcid.org/0000-0002-3659-0773
Isabelle J DionneFaculty of Physical Activity Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.

Funding

CIHRVanier Canada Graduate Scholarship
6 · The paper itself

Abstract

Head-down tilt bedrest (HDBR) models the effects of mechanical unloading on neuromuscular function. The efficacy of exercise in preserving motor unit (MU) function in older adults during HDBR remains unclear. This study investigated the effects of 14-day HDBR on MU properties in older adults and the protective role of exercise. Fifteen participants aged 55-65 years were randomized to Control group (n = 7, passive mobilization only) or Exercise group (n = 8, daily mixed resistance and aerobic training) during 14 days of strict HDBR. Knee extensor strength and leg lean mass were measured, and intramuscular EMG was used to record MU firing rate (MUFR), MU potential (MUP) area and complexity, and neuromuscular junction (NMJ) transmission instability during contractions normalized to 25% of pre-bedrest strength. Plasma C-terminal agrin fragment (CAF) was also measured. Following HDBR, knee extensor strength decreased more in the Control group (-33.4 N m; P < 0.001; ∼18% decrease) than in the Exercise group (-14.5 N m; P = 0.027; ∼8% decrease; interaction P = 0.045). Leg lean mass decreased similarly in both groups (-0.418 kg; P = 0.013). Exercise prevented the decrease in MUP area observed in Controls (-65 mV·ms, P = 0.240 vs. -253 mV·ms, P < 0.001) and led to a reduction in MUFR (-1.05 pulses/s, P < 0.001) not seen in Controls. NMJ transmission stability and CAF levels were unchanged in both groups. HDBR reduced leg lean mass and strength. Exercise attenuated declines in strength and MUP area, likely by preserving muscle fibre size despite reduced MUFR, without evidence of NMJ disruption. Exercise effectively attenuates neuromuscular decrements following HDBR in older adults, with implications for clinical care and spaceflight.

Indexed as

ageingdeconditioningdisusemotor unitspaceflightstrength

Identifiers

PMID41719153
PMCPMC13394132

What Socratic holds

Textmetadata
LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.