Effects of isokinetic training of the knee extensors on high-intensity exercise performance and skeletal muscle buffering

1994 ◽  
Vol 68 (4) ◽  
pp. 356-361 ◽  
Author(s):  
A. F. Mannion ◽  
P. M. Jakeman ◽  
P. L. T. Willan
Keyword(s):  
Skeletal Muscle ◽  
Exercise Performance ◽  
High Intensity ◽  
High Intensity Exercise ◽  
Knee Extensors ◽  
Isokinetic Training ◽  
Muscle Buffering

scholarly journals Defining the contribution of skeletal muscle pyruvate dehydrogenase α1 to exercise performance and insulin action

2018 ◽  
Vol 315 (5) ◽  
pp. E1034-E1045 ◽  
Author(s):  
Kristoffer Svensson ◽  
Jessica R. Dent ◽  
Shahriar Tahvilian ◽  
Vitor F. Martins ◽  
Abha Sathe ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Energy Expenditure ◽  
Exercise Performance ◽  
Pyruvate Dehydrogenase ◽  
High Intensity ◽  
High Intensity Exercise ◽  
Low Intensity ◽  
Low Intensity Exercise ◽  
Muscle Contractile

The pyruvate dehydrogenase complex (PDC) converts pyruvate to acetyl-CoA and is an important control point for carbohydrate (CHO) oxidation. However, the importance of the PDC and CHO oxidation to muscle metabolism and exercise performance, particularly during prolonged or high-intensity exercise, has not been fully defined especially in mature skeletal muscle. To this end, we determined whether skeletal muscle-specific loss of pyruvate dehydrogenase alpha 1 ( Pdha1), which is a critical subunit of the PDC, impacts resting energy metabolism, exercise performance, or metabolic adaptation to high-fat diet (HFD) feeding. For this, we generated a tamoxifen (TMX)-inducible Pdha1 knockout (PDHmKO) mouse, in which PDC activity is temporally and specifically ablated in adult skeletal muscle. We assessed energy expenditure, ex vivo muscle contractile performance, and endurance exercise capacity in PDHmKO mice and wild-type (WT) littermates. Additionally, we studied glucose homeostasis and insulin sensitivity in muscle after 12 wk of HFD feeding. TMX administration largely ablated PDHα in skeletal muscle of adult PDHmKO mice but did not impact energy expenditure, muscle contractile function, or low-intensity exercise performance. Additionally, there were no differences in muscle insulin sensitivity or body composition in PDHmKO mice fed a control or HFD, as compared with WT mice. However, exercise capacity during high-intensity exercise was severely impaired in PDHmKO mice, in parallel with a large increase in plasma lactate concentration. In conclusion, although skeletal muscle PDC is not a major contributor to resting energy expenditure or long-duration, low-intensity exercise performance, it is necessary for optimal performance during high-intensity exercise.

scholarly journals Acute High-Intensity Exercise Impairs Skeletal Muscle Respiratory Capacity

2018 ◽  
Vol 50 (12) ◽  
pp. 2409-2417 ◽  
Author(s):  
GWENAEL LAYEC ◽  
GREGORY M. BLAIN ◽  
MATTHEW J. ROSSMAN ◽  
SONG Y. PARK ◽  
COREY R. HART ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
High Intensity ◽  
High Intensity Exercise ◽  
Respiratory Capacity

scholarly journals Exercise and oestrogens: aerobic high-intensity exercise promotes leg vascular and skeletal muscle mitochondrial adaptations in early postmenopause

2017 ◽  
Vol 595 (20) ◽  
pp. 6379-6380 ◽  
Author(s):  
Tharmegan Tharmaratnam ◽  
Tyler Tabobondung ◽  
Taylor Tabobondung ◽  
Seyon Sivagurunathan ◽  
Mina Amin Iskandar
Keyword(s):  
Skeletal Muscle ◽  
High Intensity ◽  
High Intensity Exercise ◽  
Early Postmenopause ◽  
Mitochondrial Adaptations

scholarly journals Antioxidants Facilitate High–intensity Exercise IL–15 Expression in Skeletal Muscle

2018 ◽  
Vol 40 (01) ◽  
pp. 16-22 ◽  
Author(s):  
Alberto Pérez-López ◽  
Marcos Martin-Rincon ◽  
Alfredo Santana ◽  
Ismael Perez-Suarez ◽  
Cecilia Dorado ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Expression ◽  
High Intensity ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Acute Hypoxia ◽  
High Intensity Exercise ◽  
Oxygen Deficit ◽  
Post Exercise ◽  
Sprint Exercise

AbstractInterleukin (IL)-15 stimulates mitochondrial biogenesis, fat oxidation, glucose uptake and myogenesis in skeletal muscle. However, the mechanisms by which exercise triggers IL-15 expression remain to be elucidated in humans. This study aimed at determining whether high-intensity exercise and exercise-induced RONS stimulate IL-15/IL-15Rα expression and its signaling pathway (STAT3) in human skeletal muscle. Nine volunteers performed a 30-s Wingate test in normoxia and hypoxia (PIO2=75 mmHg), 2 h after placebo or antioxidant administration (α-lipoic acid, vitamin C and E) in a randomized double-blind design. Blood samples and muscle biopsies (vastus lateralis) were obtained before, immediately after, and 30 and 120 min post-exercise. Sprint exercise upregulated skeletal muscle IL-15 protein expression (ANOVA, P=0.05), an effect accentuated by antioxidant administration in hypoxia (ANOVA, P=0.022). In antioxidant conditions, the increased IL-15 expression at 120 min post-exercise (33%; P=0.017) was associated with the oxygen deficit caused by the sprint (r=–0.54; P=0.020); while, IL-15 and Tyr705-STAT3 AUCs were also related (r=0.50; P=0.036). Antioxidant administration promotes IL-15 protein expression in human skeletal muscle after sprint exercise, particularly in severe acute hypoxia. Therefore, during intense muscle contraction, a reduced PO2 and glycolytic rate, and possibly, an attenuated RONS generation may facilitate IL-15 production, accompanied by STAT3 activation, in a process that does not require AMPK phosphorylation.

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