ArticleThe Journal of physiology2016
Symmorphosis and skeletal muscle V̇O2 max : in vivo and in vitro measures reveal differing constraints in the exercise-trained and untrained human.
Article in The Journal of physiology, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04733287 (Improving Critical Power and Muscle Function in Older Adults With Heat Therapy), which is not on this map. Cited by 47 papers.
What it found
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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.
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.
Improving Critical Power and Muscle Function in Older Adults With Heat Therapy
Who cites it
47 citing papers in PubMed, 95 citations in OpenAlex.
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- The Improvement in Exercise Performance during Reduced Muscle Mass Exercise is Associated with an Increase in Femoral Blood Flow in Older and Younger Endurance-Trained Athletes.Journal of sports science & medicine · 2024Article
- Vascular dysfunction and the age-related decline in critical power.Experimental physiology · 2024Article
- DCS blood flow index underestimates skeletal muscle perfusionJournal of biomedical optics · 2024Article
- Endurance exercise training changes the limitation on muscleThe Journal of physiology · 2024Article
- Overdot and overline annotation must be understood to accurately interpretFrontiers in physiology · 2024Article
- Selectively breeding for high voluntary physical activity in female mice does not bestow inherent characteristics that resemble eccentric remodeling of the heart, but the mini-muscle phenotype does.Sports medicine and health science · 2023Article
- The role of the microcirculation and integrative cardiovascular physiology in the pathogenesis of ICU-acquired weakness.Frontiers in physiology · 2023Review
- Potential Role of Chronic Physical Exercise as a Treatment in the Development of Vitiligo.Frontiers in physiology · 2022Article
- Effects of high-intensity interval training with hyperbaric oxygen.Frontiers in physiology · 2022Article
- Twelve weeks of sprint interval training increases peak cardiac output in previously untrained individuals.European journal of applied physiology · 2021Article
Corrections and comments
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Authors and funding
16 authors at 2 institutions in 1 country.
Funding
Abstract
The concept of symmorphosis postulates a matching of structural capacity to functional demand within a defined physiological system, regardless of endurance exercise training status. Whether this concept applies to oxygen (O2 ) supply and demand during maximal skeletal muscle O2 consumption (V̇O2 max ) in humans is unclear. Therefore, in vitro skeletal muscle mitochondrial V̇O2 max (Mito V̇O2 max , mitochondrial respiration of fibres biopsied from vastus lateralis) was compared with in vivo skeletal muscle V̇O2 max during single leg knee extensor exercise (KE V̇O2 max , direct Fick by femoral arterial and venous blood samples and Doppler ultrasound blood flow measurements) and whole-body V̇O2 max during cycling (Body V̇O2 max , indirect calorimetry) in 10 endurance exercise-trained and 10 untrained young males. In untrained subjects, during KE exercise, maximal O2 supply (KE Q̇O2max ) exceeded (462 ± 37 ml kg(-1) min(-1) , P < 0.05) and KE V̇O2 max matched (340 ± 22 ml kg(-1) min(-1) , P > 0.05) Mito V̇O2 max (364 ± 16 ml kg(-1) min(-1) ). Conversely, in trained subjects, both KE Q̇O2max (557 ± 35 ml kg(-1) min(-1) ) and KE V̇O2 max (458 ± 24 ml kg(-1) min(-1) ) fell far short of Mito V̇O2 max (743 ± 35 ml kg(-1) min(-1) , P < 0.05). Although Mito V̇O2 max was related to KE V̇O2 max (r = 0.69, P < 0.05) and Body V̇O2 max (r = 0.91, P < 0.05) in untrained subjects, these variables were entirely unrelated in trained subjects. Therefore, in untrained subjects, V̇O2 max is limited by mitochondrial O2 demand, with evidence of adequate O2 supply, whereas, in trained subjects, an exercise training-induced mitochondrial reserve results in skeletal muscle V̇O2 max being markedly limited by O2 supply. Taken together, these in vivo and in vitro measures reveal clearly differing limitations and excesses at V̇O2 max in untrained and trained humans and challenge the concept of symmorphosis as it applies to O2 supply and demand in humans.
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Registered trials
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.