scholarly journals Relationship between V̇o2peak, cycle economy, and mitochondrial respiration in untrained/trained

2019 ◽  
Vol 127 (6) ◽  
pp. 1562-1568 ◽  
Author(s):  
Gary R. Hunter ◽  
Douglas R. Moellering ◽  
Samuel T. Windham ◽  
Shannon L. Mathis ◽  
Marcas M. Bamman ◽  
...  
Keyword(s):  
Exercise Training ◽  
Oxygen Uptake ◽  
Aerobic Exercise ◽  
Aerobic Capacity ◽  
Mitochondrial Respiration ◽  
Negative Relationship ◽  
Aerobic Exercise Training ◽  
Whole Body ◽  
Contributing Factors ◽  
Cycle Economy

Aerobic capacity is negatively related to locomotion economy. The purpose of this paper is to determine what effect aerobic exercise training has on the relationship between net cycling oxygen uptake (inverse of economy) and aerobic capacity [peak oxygen uptake (V̇o2peak)], as well as what role mitochondrial coupled and uncoupled respiration may play in whole body aerobic capacity and cycling economy. Cycling net oxygen uptake and V̇o2peak were evaluated on 31 premenopausal women before exercise training (baseline) and after 8–16 wk of aerobic training. Muscle tissue was collected from 15 subjects at baseline and post-training. Mitochondrial respiration assays were performed using high-resolution respirometry. Pre- ( r = 0.46, P < 0.01) and postexercise training ( r = 0.62, P < 0.01) V̇o2peak and cycling net oxygen uptake were related. In addition, uncoupled and coupled fat respiration were related both at baseline ( r = 0.62, P < 0.01) and post-training ( r = 0.89, P < 01). Post-training coupled ( r = 0.74, P < 0.01) and uncoupled carbohydrate respiration ( r = 0.52, P < 05) were related to cycle net oxygen uptake. In addition, correlations between V̇o2peak and cycle net oxygen uptake persist both at baseline and after training, even after adjusting for submaximal cycle respiratory quotient (an index of fat oxidation). These results suggest that the negative relationship between locomotion economy and aerobic capacity is increased following exercise training. In addition, it is proposed that at least one of the primary factors influencing this relationship has its foundation within the mitochondria. Strong relationships between coupled and uncoupled respiration appear to be contributing factors for this relationship. NEW & NOTEWORTHY The negative relationship between cycle economy and aerobic capacity is increased following exercise training. The strong relationship between coupled and uncoupled respiration, especially after training, appears to be contributing to this negative relationship between aerobic capacity and cycling economy, suggesting that mitochondrial economy is not increased following aerobic exercise training. These results are suggestive that training programs designed to improve locomotion economy should focus on changing biomechanics.

Acute high-intensity aerobic exercise increases gene expression of calcium-related proteins and activates endoplasmic reticulum stress responses in diabetic hearts

2020 ◽  
pp. 1-14
Author(s):  
H.O. Ness ◽  
K. Ljones ◽  
M. Pinho ◽  
M.A. Høydal
Keyword(s):  
Gene Expression ◽  
Exercise Training ◽  
Er Stress ◽  
Aerobic Exercise ◽  
Stress Responses ◽  
Mitochondrial Respiration ◽  
High Intensity ◽  
Acute Exercise ◽  
Contractile Function ◽  
Aerobic Exercise Training

Regular aerobic exercise training has a wide range of beneficial cardiac effects, but recent data also show that acute very strenuous aerobic exercise may impose a transient cardiac exhaustion. The aim of this study was to assess the response to acute high-intensity aerobic exercise on properties of mitochondrial respiration, cardiomyocyte contractile function, Ca2+ handling and transcriptional changes for key proteins facilitating Ca2+ handling and endoplasmic reticulum (ER) stress responses in type 2 diabetic mice. Diabetic mice were assigned to either sedentary control or an acute bout of exercise, consisting of a 10×4 minutes high-intensity interval treadmill run. Mitochondrial respiration, contractile and Ca2+ handling properties of cardiomyocytes were analysed 1 hour after completion of exercise. Gene expression levels of key Ca2+ handling and ER stress response proteins were measured in cardiac tissue samples harvested 1 hour and 24 hours after exercise. We found no significant changes in mitochondrial respiration, cardiomyocyte contractile function or Ca2+ handling 1 hour after the acute exercise. However, gene expression of Atp2a2, Slc8a1 and Ryr2, encoding proteins involved in cardiomyocyte Ca2+ handling, were all significantly upregulated 24 hours after the acute exercise bout. Acute exercise also altered gene expression of several key proteins in ER stress response and unfolded protein response, including Grp94, total Xbp1, Gadd34, and Atf6. The present results show that despite no significant alterations in functional properties of cardiomyocyte function, Ca2+ handling or mitochondrial respiration following one bout of high intensity aerobic exercise training, the expression of genes involved in Ca2+ handling and key components in ER stress and the unfolded protein response were changed. These transcriptional changes may constitute important steps in initiating adaptive remodelling to exercise training in type 2 diabetes.

Gender-dependent effects of exercise training on serum leptin levels in humans

1997 ◽  
Vol 272 (4) ◽  
pp. E562-E566 ◽  
Author(s):  
M. S. Hickey ◽  
J. A. Houmard ◽  
R. V. Considine ◽  
G. L. Tyndall ◽  
J. B. Midgette ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Exercise Training ◽  
Aerobic Exercise ◽  
Fat Mass ◽  
Aerobic Capacity ◽  
Aerobic Exercise Training ◽  
Sensitivity Index ◽  
Insulin Sensitivity Index ◽  
Serum Leptin ◽  
Body Fat Content

Leptin, the product of the ob gene, is elevated in obese humans and appears to be closely related to body fat content. The purpose of the present investigation was to determine the effect of aerobic exercise training on systemic leptin levels in humans. Eighteen sedentary middle-aged men (n = 9) and women (n = 9) who did not differ in aerobic capacity (29.4 +/- 1.2 vs. 27.5 +/- 1.2 ml x kg(-1) x min(-1)) or insulin sensitivity index (3.41 +/- 1.12 vs. 4.88 +/- 0.55) were studied. Fat mass was significantly lower in females vs. males (21.83 +/- 2.25 vs. 26.99 +/- 2.37 kg, P < 0.05). Despite this, fasting serum leptin was significantly higher in the females vs. males (18.27 +/- 2.55 vs. 9.88 +/- 1.26 ng/ml, P < 0.05). Serum leptin concentration decreased 17.5% in females (P < 0.05) after 12 wk of aerobic exercise training (4 day/wk, 30-45 min/day) but was not significantly reduced in males. Fat mass was not altered after training in either group. In contrast, both aerobic capacity (+13% males, +9.1% females) and insulin sensitivity (+35% males, +82% females) were significantly improved subsequent to training. These data suggest that 1) women have higher circulating leptin concentrations despite lower fat mass and 2) exercise training appears to have a greater effect on systemic leptin levels in females than in males.

Effect of aerobic exercise training on oxygen uptake and kinetics in patients with fibromyalgia

2009 ◽  
Vol 30 (2) ◽  
pp. 281-284 ◽  
Author(s):  
Mustafa Dinler ◽  
Demirhan Diracoglu ◽  
Erdem Kasikcioglu ◽  
Omer Sayli ◽  
Ata Akin ◽  
...  
Keyword(s):  
Exercise Training ◽  
Oxygen Uptake ◽  
Aerobic Exercise ◽  
Aerobic Exercise Training

scholarly journals Aerobic exercise training reduces arterial stiffness in metabolic syndrome

2014 ◽  
Vol 116 (11) ◽  
pp. 1396-1404 ◽  
Author(s):  
David A. Donley ◽  
Sara B. Fournier ◽  
Brian L. Reger ◽  
Evan DeVallance ◽  
Daniel E. Bonner ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Exercise Training ◽  
Arterial Stiffness ◽  
Aerobic Exercise ◽  
Aerobic Capacity ◽  
Pulse Wave ◽  
Applanation Tonometry ◽  
Aerobic Exercise Training ◽  
Arterial Stiffening ◽  
Myocardial Efficiency

The metabolic syndrome (MetS) is associated with a threefold increase risk of cardiovascular disease (CVD) mortality partly due to increased arterial stiffening. We compared the effects of aerobic exercise training on arterial stiffening/mechanics in MetS subjects without overt CVD or type 2 diabetes. MetS and healthy control (Con) subjects underwent 8 wk of exercise training (ExT; 11 MetS and 11 Con) or remained inactive (11 MetS and 10 Con). The following measures were performed pre- and postintervention: radial pulse wave analysis (applanation tonometry) was used to measure augmentation pressure and index, central pressures, and an estimate of myocardial efficiency; arterial stiffness was assessed from carotid-femoral pulse-wave velocity (cfPWV, applanation tonometry); carotid thickness was assessed from B-mode ultrasound; and peak aerobic capacity (gas exchange) was performed in the seated position. Plasma matrix metalloproteinases (MMP) and CVD risk (Framingham risk score) were also assessed. cfPWV was reduced ( P < 0.05) in MetS-ExT subjects (7.9 ± 0.6 to 7.2 ± 0.4 m/s) and Con-ExT (6.6 ± 1.8 to 5.6 ± 1.6 m/s). Exercise training reduced ( P < 0.05) central systolic pressure (116 ± 5 to 110 ± 4 mmHg), augmentation pressure (9 ± 1 to 7 ± 1 mmHg), augmentation index (19 ± 3 to 15 ± 4%), and improved myocardial efficiency (155 ± 8 to 168 ± 9), but only in the MetS group. Aerobic capacity increased ( P < 0.05) in MetS-ExT (16.6 ± 1.0 to 19.9 ± 1.0) and Con-ExT subjects (23.8 ± 1.6 to 26.3 ± 1.6). MMP-1 and -7 were correlated with cfPWV, and both MMP-1 and -7 were reduced post-ExT in MetS subjects. These findings suggest that some of the pathophysiological changes associated with MetS can be improved after aerobic exercise training, thereby lowering their cardiovascular risk.

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