scholarly journals Impaired aerobic capacity in hypercholesterolemic mice: partial reversal by exercise training

1999 ◽  
Vol 276 (4) ◽  
pp. H1346-H1354 ◽  
Author(s):  
Josef Niebauer ◽  
Andrew J. Maxwell ◽  
Patrick S. Lin ◽  
Philip S. Tsao ◽  
Jon Kosek ◽  
...  
Keyword(s):  
Exercise Training ◽  
Oxygen Uptake ◽  
Aerobic Capacity ◽  
Vascular Reactivity ◽  
Maximum Oxygen Uptake ◽  
Wild Type ◽  
Cholesterol Levels ◽  
Normal Chow ◽  
High Fat Chow ◽  
Partial Reversal

The present study assessed whether impaired aerobic capacity previously observed in hypercholesterolemic mice is reversible by exercise training. Seventy-two 8-wk-old female C57BL/6J wild-type (+, n = 42) and apolipoprotein E-deficient (−, n = 30) mice were assigned to the following eight interventions: normal chow, sedentary (E+, n = 17; E−, n = 8) or exercised ([Formula: see text], n= 13; [Formula: see text], n = 7) and high-fat chow, sedentary ([Formula: see text], n = 6;[Formula: see text], n = 8) or exercised ([Formula: see text], n = 6;[Formula: see text], n = 7). Mice were trained on a treadmill 2 × 1 h/day, 6 days/wk, for 4 wk. Cholesterol levels correlated inversely with maximum oxygen uptake ( r = −0.35; P < 0.02), which was blunted in all hypercholesterolemic sedentary groups (all P < 0.05). Maximum oxygen uptake improved in all training groups but failed to match[Formula: see text] (all P< 0.05). Vascular reactivity and nitric oxide (NO) synthesis correlated with anaerobic threshold ( r = 0.36; P < 0.025) and maximal distance run ( r = 0.59; P < 0.007). We conclude that genetically induced hypercholesterolemia impairs aerobic capacity. This adverse impact of hypercholesterolemia on aerobic capacity may be related to its impairment of vascular NO synthesis and/or vascular smooth muscle sensitivity to nitrovasodilators. Aerobic capacity is improved to the same degree by exercise training in normal and genetically hypercholesterolemic mice, although there remains a persistent difference between these groups after training.

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.

Exercise training promotes cardioprotection through oxygen-sparing action in high fat-fed mice

2015 ◽  
Vol 308 (8) ◽  
pp. H823-H829 ◽  
Author(s):  
J. Lund ◽  
A. D. Hafstad ◽  
N. T. Boardman ◽  
L. Rossvoll ◽  
N. P. Rolim ◽  
...  
Keyword(s):  
Exercise Training ◽  
Oxygen Uptake ◽  
High Fat Diet ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Interval Training ◽  
Cardiovascular Effects ◽  
Mechanical Efficiency ◽  
Maximum Oxygen Uptake ◽  
High Fat

Although exercise training has been demonstrated to have beneficial cardiovascular effects in diabetes, the effect of exercise training on hearts from obese/diabetic models is unclear. In the present study, mice were fed a high-fat diet, which led to obesity, reduced aerobic capacity, development of mild diastolic dysfunction, and impaired glucose tolerance. Following 8 wk on high-fat diet, mice were assigned to 5 weekly high-intensity interval training (HIT) sessions (10 × 4 min at 85–90% of maximum oxygen uptake) or remained sedentary for the next 10 constitutive weeks. HIT increased maximum oxygen uptake by 13%, reduced body weight by 16%, and improved systemic glucose homeostasis. Exercise training was found to normalize diastolic function, attenuate diet-induced changes in myocardial substrate utilization, and dampen cardiac reactive oxygen species content and fibrosis. These changes were accompanied by normalization of obesity-related impairment of mechanical efficiency due to a decrease in work-independent myocardial oxygen consumption. Finally, we found HIT to reduce infarct size by 47% in ex vivo hearts subjected to ischemia-reperfusion. This study therefore demonstrated for the first time that exercise training mediates cardioprotection following ischemia in diet-induced obese mice and that this was associated with oxygen-sparing effects. These findings highlight the importance of optimal myocardial energetics during ischemic stress.

scholarly journals A Correlational Study between 5-minute Run Test and Incremental Treadmill Run Test in Assessing Aerobic Capacity

2000 ◽  
Vol 6 (1) ◽  
pp. 25-29
Author(s):  
Allison Ka Yee WONG ◽  
Lobo H. LOUIE
Keyword(s):  
Linear Regression ◽  
Oxygen Uptake ◽  
Aerobic Capacity ◽  
Test Scores ◽  
Linear Regression Analysis ◽  
Maximum Oxygen Uptake ◽  
Test Results ◽  
Simple Linear Regression ◽  
Run Test ◽  
The Relationship

LANGUAGE NOTE | Document text in English; abstract also in Chinese.The purpose of this study was to determine the relationship between the 5-minute run test and the incremental treadmill run test in assessing aerobic capacity. Twenty subjects participated in this study. The maximum oxygen uptake was estimated by the 5-minute run test and directly measured by the incremental treadmill run test. Correlations were computed by the SPSS Pearson procedures. Linear regression analysis was utilized to predict the 5-minute run test scores based upon the incremental treadmill run test results in determining maximum oxygen uptake. Significant relationship was found between two tests in assessing maximum oxygen uptake. Simple linear regression showed that running velocity in 5-minute run was a significant predictor for maximum oxygen uptake measured in the incremental treadmill run test. To conclude, the 5-minute run test was valuable to predict maximum oxygen uptake.本文旨在探討兩種評估有氧能力的測試：「五分鐘跑測試」和「遞增負荷跑台測試」之關係。是次研究共有二十位受試者參與，在實驗室進行遞增負荷跑台運動測量其標準的最大攝氧量，用「五分鐘跑測試」來推測和評估其最大攝氧量，所得的資料以相關和直線回歸法分析，從而探求「五分鐘跑測試」和「遞增負荷跑台測試」之關係。研究結果顯示兩種評估有氧能力的測試有密切的關係；此外，研究員利用五分鐘平均跑速推算出最大攝氧量的回歸方程。

Felodipine Inhibits Intimal Lesion Formation in the Hypercholesterolemic Rabbit: Differential Effects on Endothelial and Monocyte Determinants of Atherogenesis

1996 ◽  
Vol 1 (3) ◽  
pp. 173-179 ◽  
Author(s):  
Bing-Yin Wang ◽  
Josef Niebauer ◽  
Alan H Singer ◽  
Philip S Tsao ◽  
John P Cooke
Keyword(s):  
Vascular Reactivity ◽  
Mononuclear Cells ◽  
Plasma Cholesterol ◽  
Cholesterol Feeding ◽  
Cell Binding ◽  
Binding Studies ◽  
Lesion Formation ◽  
Cholesterol Levels ◽  
Normal Chow ◽  
Intimal Lesion

The purpose of this study was to determine if the calcium entry antagonist felodipine inhibited intimal lesion formation in hypercholesterolemic rabbits, and to determine if this was due to an effect upon monocyte and/or endothelial determinants of this interaction. Twenty-three male New Zealand White rabbits received the following treatment regimen for 10 weeks: normal chow (NP, n = 3); normal chow with felodipine infusion (NF, n=6); 0.5% cholesterol chow (CP, n = 7); or 0.5% cholesterol chow and felodipine infusion (CF, n=7). After 10 weeks blood was collected for biochemical measurements and mononuclear cell binding assays, and thoracic aortae were harvested for vascular reactivity studies and histomorphometry. In the animals receiving normal chow, felodipine did not significantly affect blood pressure, plasma cholesterol levels, binding studies, vascular reactivity, or structure; therefore these animals were analyzed as one group (N). Plasma cholesterol levels were significantly elevated in groups receiving the 0.5% cholesterol diet (N, 29±3 mg/dl; CP, 1221±73 mg/dl; CF, 979±108 mg/dl). High-density lipoprotein cholesterol was not different between the groups (25±4 vs 23±4 vs 27±4 mg/dl; N vs CF vs CP respectively; p=NS). Cholesterol feeding markedly augmented the adhesiveness of mononuclear cells, as demonstrated by a 250% increase in cell binding. Felodipine did not alter the adhesiveness of mononuclear cells in hypercholesterolemic animals. Cholesterol feeding significantly impaired endothelium-dependent relaxations. Endothelium-dependent relaxations were restored by felodipine treatment as reflected by the maximal responses to acetylcholine (40±7% vs 58±4% vs 67±5%; CP vs CF vs N respectively). The improvement in endothelium-dependent relaxation in the felodipine-treated animals was associated with a 2.2-fold reduction in lesion surface area of the thoracic aorta (8.2±6.3% vs 18.2±9.5%; CF vs CP; p<0.01). Moreover, the intima/media ratio reflecting lesion thickness was substantially reduced by felodipine treatment (0.05±0.02 vs 0.20±0.07; CF vs CP; p=0.006). Ex vivo studies revealed that felodipine inhibited the adhesiveness of vascular endothelium, but not mononuclear cells, derived from hypercholesterolemic animals. Low-dose felodipine appears to inhibit monocyte-endothelial interaction, as indicated by a reduction in the formation of lesions in hypercholesterolemic animals. This effect is not due to an alteration in adhesiveness of mononuclear cells. The salutary effect of felodipine is associated with an increase in vascular nitric oxide activity which may reduce endothelial adhesiveness.

scholarly journals Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Bagen Liao ◽  
Yunlong Zhao ◽  
Dan Wang ◽  
Xiaowen Zhang ◽  
Xuanming Hao ◽  
...  
Keyword(s):  
Exercise Training ◽  
Oxygen Uptake ◽  
Aerobic Capacity ◽  
Ventilatory Threshold ◽  
Cardiovascular Fitness ◽  
Analysis Of Covariance ◽  
Control Group ◽  
Dosage Group ◽  
Double Blind ◽  
Nicotinamide Mononucleotide

Abstract Background Recent studies in rodents indicate that a combination of exercise training and supplementation with nicotinamide adenine dinucleotide (NAD+) precursors has synergistic effects. However, there are currently no human clinical trials analyzing this. Objective This study investigates the effects of a combination of exercise training and supplementation with nicotinamide mononucleotide (NMN), the immediate precursor of NAD+, on cardiovascular fitness in healthy amateur runners. Methods A six-week randomized, double-blind, placebo-controlled, four-arm clinical trial including 48 young and middle-aged recreationally trained runners of the Guangzhou Pearl River running team was conducted. The participants were randomized into four groups: the low dosage group (300 mg/day NMN), the medium dosage group (600 mg/day NMN), the high dosage group (1200 mg/day NMN), and the control group (placebo). Each group consisted of ten male participants and two female participants. Each training session was 40–60 min, and the runners trained 5–6 times each week. Cardiopulmonary exercise testing was performed at baseline and after the intervention, at 6 weeks, to assess the aerobic capacity of the runners. Results Analysis of covariance of the change from baseline over the 6 week treatment showed that the oxygen uptake (VO2), percentages of maximum oxygen uptake (VO2max), power at first ventilatory threshold, and power at second ventilatory threshold increased to a higher degree in the medium and high dosage groups compared with the control group. However, there was no difference in VO2max, O2-pulse, VO2 related to work rate, and peak power after the 6 week treatment from baseline in any of these groups. Conclusion NMN increases the aerobic capacity of humans during exercise training, and the improvement is likely the result of enhanced O2 utilization of the skeletal muscle. Trial registration number ChiCTR2000035138.

scholarly journals Reference values for maximum oxygen uptake relative to body mass in Dutch/Flemish subjects aged 6–65 years: the LowLands Fitness Registry

2021 ◽  
Author(s):  
Geertje E. van der Steeg ◽  
Tim Takken
Keyword(s):  
Oxygen Uptake ◽  
Body Mass ◽  
Reference Values ◽  
Cardiopulmonary Exercise Testing ◽  
European Population ◽  
Study Data ◽  
Mean Difference ◽  
Maximum Oxygen Uptake ◽  
List Type ◽  
Maximum Effort

Abstract Background The maximum oxygen uptake (VO2max) during cardiopulmonary exercise testing (CPET) is considered the best measure of cardiorespiratory fitness. Aim To provide up-to-date reference values for the VO2max per kilogram of body mass (VO2max/kg) obtained by CPET in the Netherlands and Flanders. Methods The Lowlands Fitness Registry contains data from health checks among different professions and was used for this study. Data from 4612 apparently healthy subjects, 3671 males and 941 females, who performed maximum effort during cycle ergometry were analysed. Reference values for the VO2max/kg and corresponding centile curves were created according to the LMS method. Results Age had a negative significant effect (p < .001) and males had higher values of VO2max/kg with an overall difference of 18.0% compared to females. Formulas for reference values were developed: Males: VO2max/kg = − 0.0049 × age2 + 0.0884 × age + 48.263 (R2 = 0.9859; SEE = 1.4364) Females: VO2max/kg = − 0.0021 × age2 − 0.1407 × age + 43.066 (R2 = 0.9989; SEE = 0.5775). Cross-validation showed no relevant statistical mean difference between measured and predicted values for males and a small but significant mean difference for females. We found remarkable higher VO2max/kg values compared to previously published studies. Conclusions This is the first study to provide reference values for the VO2max/kg based on a Dutch/Flemish cohort. Our reference values can be used for a more accurate interpretation of the VO2max in the West-European population.

scholarly journals The Effect of Eight-Week Sprint Interval Training on Aerobic Performance of Elite Badminton Players

2021 ◽  
Vol 18 (2) ◽  
pp. 638
Author(s):  
Haochong Liu ◽  
Bo Leng ◽  
Qian Li ◽  
Ye Liu ◽  
Dapeng Bao ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Anaerobic Threshold ◽  
Aerobic Capacity ◽  
Interval Training ◽  
Lactate Clearance ◽  
Aerobic Performance ◽  
Sprint Interval Training ◽  
Control Groups ◽  
Ventilatory Anaerobic Threshold ◽  
And Control

This study was aimed to: (1) investigate the effects of physiological functions of sprint interval training (SIT) on the aerobic capacity of elite badminton players; and (2) explore the potential mechanisms of oxygen uptake, transport and recovery within the process. Thirty-two elite badminton players volunteered to participate and were randomly divided into experimental (Male-SIT and Female-SIT group) and control groups (Male-CON and Female-CON) within each gender. During a total of eight weeks, SIT group performed three times of SIT training per week, including two power bike trainings and one multi-ball training, while the CON group undertook two Fartlek runs and one regular multi-ball training. The distance of YO-YO IR2 test (which evaluates player’s ability to recover between high intensity intermittent exercises) for Male-SIT and Female-SIT groups increased from 1083.0 ± 205.8 m to 1217.5 ± 190.5 m, and from 725 ± 132.9 m to 840 ± 126.5 m (p < 0.05), respectively, which were significantly higher than both CON groups (p < 0.05). For the Male-SIT group, the ventilatory anaerobic threshold and ventilatory anaerobic threshold in percentage of VO2max significantly increased from 3088.4 ± 450.9 mL/min to 3665.3 ± 263.5 mL/min (p < 0.05),and from 74 ± 10% to 85 ± 3% (p < 0.05) after the intervention, and the increases were significantly higher than the Male-CON group (p < 0.05); for the Female-SIT group, the ventilatory anaerobic threshold and ventilatory anaerobic threshold in percentage of VO2max were significantly elevated from 1940.1 ± 112.8 mL/min to 2176.9 ± 78.6 mL/min, and from 75 ± 4% to 82 ± 4% (p < 0.05) after the intervention, which also were significantly higher than those of the Female-CON group (p < 0.05). Finally, the lactate clearance rate was raised from 13 ± 3% to 21 ± 4% (p < 0.05) and from 21 ± 5% to 27 ± 4% for both Male-SIT and Female-SIT groups when compared to the pre-test, and this increase was significantly higher than the control groups (p < 0.05). As a training method, SIT could substantially improve maximum aerobic capacity and aerobic recovery ability by improving the oxygen uptake and delivery, thus enhancing their rapid repeated sprinting ability.

Cycling Exercise Training Enhances Platelet Mitochondrial Bioenergetics in Patients with Peripheral Arterial Disease: A Randomized Controlled Trial

2021 ◽  
Author(s):  
Tieh-Cheng Fu ◽  
Ming-Lu Lin ◽  
Chih-Chin Hsu ◽  
Shu-Chun Huang ◽  
Yu-Ting Lin ◽  
...  
Keyword(s):  
Exercise Training ◽  
Peripheral Arterial Disease ◽  
Aerobic Capacity ◽  
Short Form ◽  
Arterial Disease ◽  
Control Group ◽  
Mitochondrial Bioenergetics ◽  
Cycling Exercise ◽  
Complex Ii ◽  
Peripheral Arterial

AbstractExercise training influences the risk of vascular thrombosis in patients with peripheral arterial disease (PAD). Mitochondrial functionalities in platelets involve the cellular bioenergetics and thrombogenesis. This study aimed to elucidate the effect of cycling exercise training (CET) on platelet mitochondrial bioenergetics in PAD patients. Forty randomly selected patients with PAD engaged in general rehabilitation (GR) with CET (i.e., cycling exercise at ventilation threshold for 30 minute/day, 3 days/week) (GR + CET, n = 20) or to a control group that only received GR course (n = 20) for 12 weeks. Systemic aerobic capacity and platelet mitochondrial bioenergetics that included oxidative phosphorylation (OXPHOS) and electron transport system (ETS) were measured using automatic gas analysis and high-resolution respirometry, respectively. The experimental results demonstrated that GR + CET for 12 weeks significantly (1) elevated VO2peak and lowered VE-VCO2 slope, (2) raised resting ankle-brachial index and enhanced cardiac output response to exercise, (3) increased the distance in 6-minute walk test and raised the Short Form-36 physical/mental component scores, and (4) enhanced capacities of mitochondrial OXPHOS and ETS in platelets by activating FADH2 (complex II)-dependent pathway. Moreover, changes in VO2peak levels were positively associated with changes in platelet OXPHOS and ETS capacities. However, no significant changes in systemic aerobic capacity, platelet mitochondrial bioenergetics, and health-related quality of life (HRQoL) occurred following GR alone. Hence, we conclude that CET effectively increases the capacities of platelet mitochondrial bioenergetics by enhancing complex II activity in patients with PAD. Moreover, the exercise regimen also enhanced functional exercise capacity, consequently improving HRQoL in PAD patients.

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