Search results for "Exertion"

Stay Home, Stay Active with SuperJump®: A Home-Based Activity to Prevent Sedentary Lifestyle during COVID-19 Outbreak

2020

The purpose of this study was to investigate the intensity of SuperJump® workout as a home-based activity for fulfilling physical activity recommendations during COVID-19 home-confinement. Seventeen (males: n = 10; females: n = 7) college students (age: 25.8 ± 2.7 years; height: 1.7 ± 0.1 m; weight: 66.2 ± 12.1 kg) participated in the study. To assess the intensity of the activity (30-min), heart rate (HR), expressed as percentages of age-predicted maximal HR (%HRmax), and session ratings of perceived exertion (sRPE), collected on a CR10 scale, were used. %HRmax data were categorically separated in five classes of intensity according to the American College of Sport…

The cardinal exercise stopper: Muscle fatigue, muscle pain or perception of effort?

2018

The capacity to sustain high-intensity aerobic exercise is essential for endurance performance. Therefore, it is important to understand what is the factor limiting time to exhaustion (TTE) in healthy and fit adults. In Study 1, maximal voluntary cycling power (MVCP) was measured in 11 volunteers before and immediately after a high-intensity TTE test on cycle ergometer. Cadence was 60 rpm in both the MVCP and TTE tests. Despite a 35% loss in MVCP, power produced during the final MVCP test (mean ± SD 469 ± 111 W) was significantly higher than the power required by the TTE test (269 ± 55 W) (P < 0.001). In Study 2, 12 participants performed a cold pressor test (CPT) to the limit of tolerance …

Stress cardiovascular magnetic resonance and mortality in a registry of 2496 elderly patients with chronic coronary syndrome. Prognosis and decision-…

2021

Abstract Funding Acknowledgements Type of funding sources: None. Background. In recent guidelines, non-invasive imaging techniques play a pivotal role in the management of chronic coronary syndrome (CCS). The elderly represent a large percentage of our routine CCS population and risk stratification in this scenario is challenging. The potential of vasodilator stress cardiovascular magnetic resonance (CMR) for this purpose is unknown. Purpose. We explore the prognostic value and the usefulness for decision-making of the ischemic burden determined by vasodilator stress CMR imaging in a large cohort of elderly patients with known or suspected CCS. Methods. The study group was made up of 2496 p…

Metabolic changes in skeletal muscle of frog during exercise and recovery.

1991

Increased mRNAs for procollagens and key regulating enzymes in rat skeletal muscle following downhill running.

1999

The purpose of the study was to investigate pre-translational regulation of collagen expression after a single bout of exercise. We analysed steady-state messenger ribonucleic acid (mRNA) levels for collagen types I, III and IV, alpha- and beta-subunits of prolyl 4-hydroxylase and lysyl oxidase (enzymes modifying procollagen chains), and enzyme activity of prolyl 4-hydroxylase from rat soleus muscle (MS) and the red parts of quadriceps femoris muscle (MQF) after 12 h and after 1, 2, 4, 7 and 14 days of downhill (-13.5 degrees ) treadmill running at a speed of 17 m.min-1 for 130 min. Histological and biochemical assays revealed exercise-induced muscle damage in MQF but not MS. Steady-state m…

C-Reactive Protein Is Elevated Only in High Creatine Kinase Responders to Muscle Damaging Exercise.

2019

The purpose of this study was to investigate if exertional rhabdomyolysis induced by an acute bout of plyometric exercise in untrained individuals was associated with histological characteristics of skeletal muscle, creatine kinase (CK) polymorphism or secondary damage. Twenty-six healthy male untrained individuals completed a bout of plyometric exercise (10 sets of 10 maximal squat jumps, with each standardized to achieve at least 95% of individual maximal jump height). Blood samples were taken, and perceived pain was scored immediately before the exercise intervention and 6 h, 1, 2, and 3 days post-intervention. Muscle biopsies were collected 9 or 4 days before (baseline) and 3 days after…

Intrinsic changes on automatism, conduction, and refractoriness by exercise in isolated rabbit heart.

2001

We have studied the intrinsic modifications on myocardial automatism, conduction, and refractoriness produced by chronic exercise. Experiments were performed on isolated rabbit hearts. Trained animals were submitted to exercise on a treadmill. The parameters investigated were 1) R-R interval, noncorrected and corrected sinus node recovery time (SNRT) as automatism index; 2) sinoatrial conduction time; 3) Wenckebach cycle length (WCL) and retrograde WCL, as atrioventricular (A-V) and ventriculoatrial conduction index; and 4) effective and functional refractory periods of left ventricle, A-V node, and ventriculoatrial retrograde conduction system. Measurements were also performed on coronary…

Acute exercise induced changes in rat skeletal muscle mRNAs and proteins regulating type IV collagen content

2001

This experiment tested the hypothesis that running-induced damage to rat skeletal muscle causes changes in synthesis and degradation of basement membrane type IV collagen and to proteins regulating its degradation. Samples from soleus muscle and red and white parts of quadriceps femoris muscle (MQF) were collected 6 h or 1, 2, 4, or 7 days after downhill running. Increased muscle β-glucuronidase activity indicated greater muscle damage in the red part of MQF than in the white part of MQF or soleus. In the red part of MQF, type IV collagen expression was upregulated at the pretranslational level and the protein concentration decreased, whereas matrix metalloproteinase-2 (MMP-2), a protein th…

Studies using pharmacological blockade of muscle afferents provide new insights into the neurophysiology of perceived exertion

2016

The increase in blood pressure observed during physical activities is exaggerated in patients with hypertension, exposing them to a higher cardiovascular risk.Neural signals from the skeletal muscles appear to be overactive, resulting in this abnormal response in hypertensive patients.In the present study, we tested whether the attenuation of these neural signals in hypertensive patients could normalize their abnormal increase in blood pressure during physical activity.Attenuation of the neural signals from the leg muscles with intrathecal fentanyl injection reduced the blood pressure of hypertensive men during cycling exercise to a level comparable to that of normotensive men.Skeletal musc…

Cardiorespiratory responses to basic aquatic exercise – A pilot study

2006

This study aimed to examine cardiorespiratory responses to six basic aquatic exercises and to compare the impact of the exercises between healthy females (H group, n=10) and females with diagnosed cardiopulmonary diseases (C group, n=10). The average age of the participants was 52.6(±5.9) years. Each exercise was performed for 3 min. During the exercises, heart rate (HR), oxygen consumption (VO2), blood lactate concentration (BLA), and rate of perceived exertion (RPE) were measured. In each pair of exercises, the latter part was more strenuous than the first. Walking in place was least and cross-country skiing the most strenuous mode of exercise. Energy expenditure (EE) ranged between 2.5±0…