Moderate‐intensity training in hypoxia improves exercise performance and glycolytic capacity of skeletal muscle in horses

We investigated the effects of 3 wk of moderate- (21 m/min, 8% grade) and highintensity treadmill training (31 m/min, 15% grade) on 1) monocarboxylate transporter 1 (MCT-1) content in rat hindlimb muscles and the heart and 2) lactate uptake in isolated soleus (Sol) muscles and perfused hearts. In the moderately trained group MCT-1 was not increased in any of the muscles [Sol, extensor digitorum longus (EDL), and red (RG) and white gastrocnemius (WG)] ( P > 0.05). Similarly, lactate uptake in Sol strips was also not increased ( P > 0.05). In contrast, in the heart, MCT-1 (+36%, P < 0.05) and lactate uptake (+72%, P < 0.05) were increased with moderate training. In the highly trained group, MCT-1 (+70%, P < 0.05) and lactate uptake (+79%, P < 0.05) were increased in Sol. MCT-1 was also increased in RG (+94%, P < 0.05) but not in WG and EDL ( P > 0.05). In the highly trained group, heart MCT-1 (+44%, P < 0.05) and lactate uptake (+173%, P < 0.05) were increased. In conclusion, it has been shown that 1) in both heart and skeletal muscle lactate uptake is increased only when MCT-1 is increased; 2) training-induced increases in MCT-1 occurred at a lower training intensity in the heart than in skeletal muscle; 3) in the heart, lactate uptake was increased much more after high-intensity training than after moderate-intensity training, despite similar increases in heart MCT-1 with these two training intensities; and 4) the increases in MCT-1 occurred independently of any changes in the heart’s oxidative capacity (as measured by citrate synthase activity).

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The Effects of Exercise Regimens on Irisin Levels in Obese Rats Model: Comparing High-Intensity Intermittent with Continuous Moderate-Intensity Training

BioMed Research International ◽

10.1155/2018/4708287 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Neng Tine Kartinah ◽

Imelda Rosalyn Sianipar ◽

Nafi’ah ◽

Rabia

Keyword(s):

Skeletal Muscle ◽

Adipose Tissue ◽

High Intensity ◽

Moderate Intensity ◽

Sprague Dawley ◽

Beneficial Effects ◽

Metabolic Condition ◽

Obese Rats ◽

Metabolic Conditions ◽

Intensity Training

Background. Recently, high-intensity intermittent training (HIIT) appears to have the same beneficial effects or even superior to those of continuous moderate-intensity training (CMIT) on body fat mass reduction. Exercise may induce myokine secretion such as irisin, which plays a role as a mediator of beiging process, and thus might contribute as treatment of obesity. However, the effects of those exercise formulas on irisin level changes as beiging agent are not known. In addition, metabolic states may affect the irisin responses to those exercise formulas. Therefore, this study was aimed to determine the different effects of exercises using HIIT and CMIT on circulating and tissue irisin levels in normal and abnormal metabolic conditions (obese). Methods. Sixteen male Sprague-Dawley rats (8 weeks of age) were randomized to 4 groups according to training regimens (HIIT and CMIT) and metabolic conditions (normal and abnormal/obese). The groups are (1) HIIT on normal metabolic (n=4), (2) CMIT on normal metabolic (n=4), (3) HIIT on abnormal metabolic (n=4), and (4) CMIT on abnormal metabolic (n=4). Abnormal metabolic condition was induced with high fat diet (19% fat) for 8 weeks in obese rats. Irisin levels in serum, skeletal muscle, and white adipose tissue were evaluated by ELISA. Results. Serum irisin levels were shown significantly higher in normal metabolic compared to abnormal metabolic condition (P<0.001). The effect of interaction between metabolic condition and exercise formula was found (P<0.01) on adipose irisin levels. The effect of HIIT was shown significantly more effective on adipose irisin levels, compared with CMIT in abnormal metabolic conditions. However, no significant differences of skeletal muscle irisin levels were found in both normal and abnormal metabolic subjects (P>0.05). Regarding exercise formula, no different effects were found between HIIT and CMIT on skeletal muscle irisin levels in both metabolic conditions (P>0.05). The similar findings were observed in serum irisin levels (P>0.05). Conclusions. The exercise effects in abnormal metabolic condition might be more adaptable in maintaining the irisin levels in skeletal muscle and induce the irisin uptake from circulation into adipose tissue. In addition, HIIT might be more involved to induce irisin uptake into adipose tissue; thus it might have the significant role in beiging process. However, further research about how the HIIT formula affects the regulation mechanisms of irisin uptake into adipose tissue is still warranted.

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Faculty Opinions recommendation of Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1040494.497646 ◽

2006 ◽

Author(s):

Mark Hargreaves

Keyword(s):

Skeletal Muscle ◽

Endurance Training ◽

Exercise Performance ◽

Human Skeletal Muscle ◽

Short Term

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Faculty Opinions recommendation of Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1040494.489473 ◽

2006 ◽

Author(s):

James Timmons

Keyword(s):

Skeletal Muscle ◽

Endurance Training ◽

Exercise Performance ◽

Human Skeletal Muscle ◽

Short Term

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Faculty Opinions recommendation of Adult skeletal muscle deletion of Mitofusin 1 and 2 impedes exercise performance and training capacity.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734091317.793559687 ◽

2019 ◽

Author(s):

Kimberly A Huey

Keyword(s):

Skeletal Muscle ◽

Exercise Performance ◽

Adult Skeletal Muscle ◽

Training Capacity ◽

Mitofusin 1 ◽

And Training

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AUF1 Gene Transfer Increases Exercise Performance and Improves Skeletal Muscle Deficit in Adult Mice

Molecular Therapy — Methods & Clinical Development ◽

10.1016/j.omtm.2021.07.005 ◽

2021 ◽

Author(s):

Dounia Abbadi ◽

John J. Andrews ◽

Olga Katsara ◽

Robert J. Schneider

Keyword(s):

Skeletal Muscle ◽

Gene Transfer ◽

Exercise Performance ◽

Adult Mice

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Increasing skeletal muscle carnitine content in older individuals increases whole‐body fat oxidation during moderate‐intensity exercise

Aging Cell ◽

10.1111/acel.13303 ◽

2021 ◽

Vol 20 (2) ◽

Author(s):

Carolyn Chee ◽

Chris E. Shannon ◽

Aisling Burns ◽

Anna L. Selby ◽

Daniel Wilkinson ◽

...

Keyword(s):

Skeletal Muscle ◽

Body Fat ◽

Fat Oxidation ◽

Whole Body ◽

Moderate Intensity ◽

Older Individuals ◽

Moderate Intensity Exercise

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Expression of the Irisin Precursor FNDC5 in Skeletal Muscle Correlates With Aerobic Exercise Performance in Patients With Heart Failure

Circulation Heart Failure ◽

10.1161/circheartfailure.112.969543 ◽

2012 ◽

Vol 5 (6) ◽

pp. 812-818 ◽

Cited By ~ 119

Author(s):

Stewart H. Lecker ◽

Alexandra Zavin ◽

Peirang Cao ◽

Ross Arena ◽

Kelly Allsup ◽

...

Keyword(s):

Heart Failure ◽

Skeletal Muscle ◽

Aerobic Exercise ◽

Exercise Performance ◽

Patients With Heart Failure

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Role of the AMP-activated protein kinase in regulating fatty acid metabolism during exerciseThis paper is one of a selection of papers published in this Special Issue, entitled 14th International Biochemistry of Exercise Conference – Muscles as Molecular and Metabolic Machines, and has undergone the Journal’s usual peer review process.

Applied Physiology Nutrition and Metabolism ◽

10.1139/h09-009 ◽

2009 ◽

Vol 34 (3) ◽

pp. 315-322 ◽

Cited By ~ 26

Author(s):

Gregory R. Steinberg

Keyword(s):

Skeletal Muscle ◽

Fatty Acids ◽

Adipose Tissue ◽

Fatty Acid ◽

Protein Kinase ◽

Fatty Acid Metabolism ◽

Acid Metabolism ◽

Moderate Intensity ◽

Amp Activated Protein Kinase

During moderate-intensity exercise, fatty acids are the predominant substrate for working skeletal muscle. The release of fatty acids from adipose tissue stores, combined with the ability of skeletal muscle to actively fine tune the gradient between fatty acid and carbohydrate metabolism, depending on substrate availability and energetic demands, requires a coordinated system of metabolic control. Over the past decade, since the discovery that AMP-activated protein kinase (AMPK) was increased in accordance with exercise intensity, there has been significant interest in the proposed role of this ancient stress-sensing kinase as a critical integrative switch controlling metabolic responses during exercise. In this review, studies examining the role of AMPK as a regulator of fatty acid metabolism in both adipose tissue and skeletal muscle during exercise will be discussed. Exercise induces activation of AMPK in adipocytes and regulates triglyceride hydrolysis and esterfication through phosphorylation of hormone sensitive lipase (HSL) and glycerol-3-phosphate acyl-transferase, respectively. In skeletal muscle, exercise-induced activation of AMPK is associated with increases in fatty acid uptake, phosphorylation of HSL, and increased fatty acid oxidation, which is thought to occur via the acetyl-CoA carboxylase-malony-CoA-CPT-1 signalling axis. Despite the importance of AMPK in regulating fatty acid metabolism under resting conditions, recent evidence from transgenic models of AMPK deficiency suggest that alternative signalling pathways may also be important for the control of fatty acid metabolism during exercise.

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