Evidence map›Paper›PMID 39251444›Full record

ArticleEuropean journal of applied physiology2025

Muscle microvascular oxygen delivery limitations during the contraction phase of intermittent maximal effort contractions.

Kylie N Sears, Tony R Montgomery, Colin W Kipper, Petra Kis, Taylor K Dinyer-McNeely, Shane M Hammer

Abstract read
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Article in European journal of applied physiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing 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

2 citing papers in PubMed.

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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

6 authors.

Kylie N SearsSchool of Kinesiology, Applied Health, and Recreation, Oklahoma State University, 180 Colvin Recreation Center, Stillwater, OK, 74078, USA.
Tony R MontgomerySchool of Kinesiology, Applied Health, and Recreation, Oklahoma State University, 180 Colvin Recreation Center, Stillwater, OK, 74078, USA.
Colin W KipperSchool of Kinesiology, Applied Health, and Recreation, Oklahoma State University, 180 Colvin Recreation Center, Stillwater, OK, 74078, USA.
Petra KisSchool of Kinesiology, Applied Health, and Recreation, Oklahoma State University, 180 Colvin Recreation Center, Stillwater, OK, 74078, USA.
Taylor K Dinyer-McNeelySchool of Kinesiology, Applied Health, and Recreation, Oklahoma State University, 180 Colvin Recreation Center, Stillwater, OK, 74078, USA.
Shane M HammerSchool of Kinesiology, Applied Health, and Recreation, Oklahoma State University, 180 Colvin Recreation Center, Stillwater, OK, 74078, USA. shane.hammer@okstate.edu.ORCID http://orcid.org/0000-0003-1937-294X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeThe end-test torque (ETT) during intermittent maximal effort contractions reflects the highest contraction intensity at which a muscle metabolic steady-state can be attained. This study determined if ETT is the highest intensity at which the contraction phase of intermittent exercise does not limit the matching of microvascular oxygen delivery to muscle oxygen demand.

methodsMicrovascular oxygenation characteristics of the biceps brachii muscle were measured in sixteen young, healthy individuals (8M/8F, 22 ± 3 years, 80.9 ± 20.3 kg) by near-infrared spectroscopy during maximal effort elbow flexion under control conditions (CON) and with complete circulatory occlusion (OCC).

resultsIncreases in total-[heme] were blunted during OCC compared to CON (225 ± 87 vs. 264 ± 88 μM, p < 0.001) but OCC did not elicit a compensatory increase in deoxygenated-[heme] at any timepoint (108 ± 62 vs. 101 ± 61 μM, p > 0.05). Deoxygenated-[heme] was significantly elevated during contraction, relative to relaxation, above ETT (107 ± 60 vs. 98.8 ± 60.5 μM, p < 0.001), but not at ETT (91.7 ± 54.1 vs. 98.4 ± 62.2 μM, p = 0.174). Total-[heme] was significantly reduced during contraction, relative to relaxation, at all contraction intensities during CON (p < 0.05) and OCC (p < 0.05).

conclusionThese data suggest that ETT may reflect the highest contraction intensity at which contraction-induced increases in intramuscular pressures do not limit muscle perfusion to a degree that requires further increases in fractional oxygen extraction (i.e., deoxygenated-[heme]) despite limited microvascular diffusive conductance (i.e., total-[heme]).

Indexed as

Muscle ContractionMuscle, SkeletalOxygenOxygen ConsumptionAdultFemaleHumansMaleMicrocirculationSpectroscopy, Near-InfraredYoung AdultOxygenContractionCritical torqueMicrovascularNear-infrared spectroscopyOxygen delivery

Identifiers

PMID39251444

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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 OpenQuestion graph.