Do changes in mitochondrial quality contribute to increases in skeletal muscle oxidative capacity following endurance training?

Bartlett, Miles F.; Miehm, Jules D.; Fitzgerald, Liam F.; Straight, Chad R.

doi:10.1113/jp273809

Cited by 5 publications

(3 citation statements)

References 6 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, the improvement in mass-specific mitochondrial respiration usually reported at the end of an endurance exercise intervention usually disappears when mitochondrial respiration is normalized to a mitochondrial parameter such as mitochondrial protein content or CS activity ( Granata et al, 2016 ; MacInnis et al, 2016 ). Accordingly, it is unclear which training regimen stimulates intrinsic mitochondrial respiration and which mitochondrial components underlie increased intrinsic mitochondrial respiration ( Bartlett et al, 2017 ). A plausible locus of regulation is the mitochondrial cristae, which until recently has been thought to be of constant density relative to mitochondrial volume among individuals; however, differences between active individuals and elite athletes was recently discovered ( Nielsen et al, 2016 ).…”

Section: Discussionmentioning

confidence: 99%

Superior Intrinsic Mitochondrial Respiration in Women Than in Men

et al. 2018

View full text Add to dashboard Cite

Sexual dimorphism is apparent in humans, however, to date no studies have investigated mitochondrial function focusing on intrinsic mitochondrial respiration (i.e., mitochondrial respiration for a given amount of mitochondrial protein) and mitochondrial oxygen affinity (p50mito) in relation to biological sex in human. A skeletal muscle biopsy was donated by nine active women, and ten men matched for maximal oxygen consumption (VO2max) and by nine endurance trained men. Intrinsic mitochondrial respiration, assessed in isolated mitochondria, was higher in women compared to men when activating complex I (CIP) and complex I+II (CI+IIP) (p < 0.05), and was similar to trained men (CIP, p = 0.053; CI+IIP, p = 0.066). Proton leak and p50mito were higher in women compared to men independent of VO2max. In conclusion, significant novel differences in mitochondrial oxidative function, intrinsic mitochondrial respiration and p50mito exist between women and men. These findings may represent an adaptation in the oxygen cascade in women to optimize muscle oxygen uptake to compensate for a lower oxygen delivery during exercise.

show abstract

Section: Discussionmentioning

confidence: 99%

Superior Intrinsic Mitochondrial Respiration in Women Than in Men

et al. 2018

View full text Add to dashboard Cite

show abstract

“…These results indicate that the skeletal muscle oxidative capacity was enhanced by an increase in intrinsic mitochondrial respiration more than an upregulation of mitochondrial content. Although mitochondrial oxidative capacity is usually reported increased following endurance training by an increased mitochondrial content more than a higher intrinsic mitochondrial respiration ( Bartlett et al, 2017 ; Macinnis et al, 2017 ), a dissociation between these two parameters has been previously reported in humans ( Granata et al, 2016 ; Larsen et al, 2016 , 2018 ; Lundby et al, 2018 ). It can be speculated that the testosterone treatment may have altered the protein aggregations of the mitochondrial respiratory complexes i.e., supercomplexes ( Schagger and Pfeiffer, 2000 ) and/or increased mitochondrial cristae density ( Nielsen et al, 2017 ) thus enhancing intrinsic mitochondrial respiration as it has been observed following exercise training ( Greggio et al, 2017 ).…”

Section: Discussionmentioning

confidence: 91%

Enhanced Skeletal Muscle Oxidative Capacity and Capillary-to-Fiber Ratio Following Moderately Increased Testosterone Exposure in Young Healthy Women

et al. 2020

View full text Add to dashboard Cite

Background: Recently, it was shown that exogenously administered testosterone enhances endurance capacity in women. In this study, our understanding on the effects of exogenous testosterone on key determinants of oxygen transport and utilization in skeletal muscle is expanded.Methods: In a double-blinded, randomized, placebo-controlled trial, 48 healthy active women were randomized to 10 weeks of daily application of 10 mg of testosterone cream or placebo. Before and after the intervention, VO2 max, body composition, total hemoglobin (Hb) mass and blood volumes were assessed. Biopsies from the vastus lateralis muscle were obtained before and after the intervention to assess mitochondrial protein abundance, capillary density, capillary-to-fiber (C/F) ratio, and skeletal muscle oxidative capacity.Results: Maximal oxygen consumption per muscle mass, Hb mass, blood, plasma and red blood cell volumes, capillary density, and the abundance of mitochondrial protein levels (i.e., citrate synthase, complexes I, II, III, IV-subunit 2, IV-subunit 4, and V) were unchanged by the intervention. However, the C/F ratio, specific mitochondrial respiratory flux activating complex I and linked complex I and II, uncoupled respiration and electron transport system capacity, but not leak respiration or fat respiration, were significantly increased following testosterone administration compared to placebo.Conclusion: This study provides novel insights into physiological actions of increased testosterone exposure on key determinants of oxygen diffusion and utilization in skeletal muscle of women. Our findings show that higher skeletal muscle oxidative capacity coupled to higher C/F ratio could be major contributing factors that improve endurance performance following moderately increased testosterone exposure.

show abstract

“…Our finding is supported by a previous study investigating the effects of moderate intensity continuous exercise or high-intensity interval training in healthy participants [ 25 ]. Based on these observations, it has recently been postulated that mitochondrial quality improvements do only occur once mitochondrial content has increased to the limit allowed by spatial constraints of the muscle fibers [ 26 ].…”

Section: Discussionmentioning

confidence: 99%

Effects of endurance training on skeletal muscle mitochondrial function in Huntington disease patients

Mueller

Gehrig

Petersen

et al. 2017

Orphanet J Rare Dis

View full text Add to dashboard Cite

BackgroundMitochondrial dysfunction may represent a pathogenic factor in Huntington disease (HD). Physical exercise leads to enhanced mitochondrial function in healthy participants. However, data on effects of physical exercise on HD skeletal muscle remains scarce. We aimed at investigating adaptations of the skeletal muscle mitochondria to endurance training in HD patients.MethodsThirteen HD patients and 11 healthy controls completed 26 weeks of endurance training. Before and after the training phase muscle biopsies were obtained from M. vastus lateralis. Mitochondrial respiratory chain complex activities, mitochondrial respiratory capacity, capillarization, and muscle fiber type distribution were determined from muscle samples.ResultsCitrate synthase activity increased during the training intervention in the whole cohort (P = 0.006). There was no group x time interaction for citrate synthase activity during the training intervention (P = 0.522). Complex III (P = 0.008), Complex V (P = 0.043), and succinate cytochrome c reductase (P = 0.008) activities increased in HD patients and controls by endurance training. An increase in mass-specific mitochondrial respiratory capacity was present in HD patients during the endurance training intervention. Overall capillary-to-fiber ratio increased in HD patients by 8.4% and in healthy controls by 6.4% during the endurance training intervention.ConclusionsSkeletal muscle mitochondria of HD patients are equally responsive to an endurance-training stimulus as in healthy controls. Endurance training is a safe and feasible option to enhance indices of energy metabolism in skeletal muscle of HD patients and may represent a potential therapeutic approach to delay the onset and/or progression of muscular dysfunction.Trial registrationClinicalTrials.gov NCT01879267. Registered May 24, 2012.

show abstract

Do changes in mitochondrial quality contribute to increases in skeletal muscle oxidative capacity following endurance training?

Cited by 5 publications

References 6 publications

Superior Intrinsic Mitochondrial Respiration in Women Than in Men

Superior Intrinsic Mitochondrial Respiration in Women Than in Men

Enhanced Skeletal Muscle Oxidative Capacity and Capillary-to-Fiber Ratio Following Moderately Increased Testosterone Exposure in Young Healthy Women

Effects of endurance training on skeletal muscle mitochondrial function in Huntington disease patients

Contact Info

Product

Resources

About