Search results for "OXYGEN UPTAKE"
showing 10 items of 56 documents
Evolution of electromyographic signal, running economy, and perceived exertion during different prolonged exercises
2000
International audience; The purpose of this study was to compare the electromyographic (EMG) signal of the vastus lateralis muscle obtained during a run section of a triathlon and at the end of a prolonged run performed at the same running velocity. Seven subjects were studied on three occasions: a 2 h 15 min triathlon (30 min swimming, 60 min cycling, and 45 min treadmill running at 75% of the maximal aerobic speed), a 2 h 15 min run, where the last 45 min (Prolonged Run, PR) were run at the same speed as the Triathlon Run (TR) on a motorized treadmill, and a 45 min Isolated Run (IR) performed at the same TR and PR velocity. The three experimental trials were randomised. Oxygen uptake (VO …
Evidence of neuromuscular fatigue after prolonged cycling exercise
2000
International audience; Purpose: The purpose of this study was to analyze the effects of prolonged cycling exercise on metabolic, neuromuscular, and biomechanical parameters. Methods: Eight well-trained male cyclists or triathletes performed a 2-h cycling exercise at a power output corresponding to 65% of their maximal aerobic power. Maximal concentric (CON; 60, 120, 240°s 1), isometric (ISO; 0°s 1), and eccentric (ECC; 120,-60°s 1) contractions, electromyographic (EMG) activity of vastus lateralis (VL) and vastus medialis (VM) muscles were recorded before and after the exercise. Neural (M-wave) and contractile (isometric muscular twitch) parameters of quadriceps muscle were also analyzed u…
Cardiorespiratory Changes During Prolonged Downhill Versus Uphill Treadmill Exercise
2020
AbstractOxygen uptake (V̇O2), heart rate (HR), energy cost (EC) and oxygen pulse are lower during downhill compared to level or uphill locomotion. However, a change in oxygen pulse and EC during prolonged grade exercise is not well documented. This study investigated changes in cardiorespiratory responses and EC during 45-min grade exercises. Nine male healthy volunteers randomly ran at 75% HR reserve during 45-min exercise in a level (+1%), uphill (+15%) or downhill (−15%) condition. V̇O2 , minute ventilation (V̇E ) and end-tidal carbon dioxide (PetCO2) were recorded continuously with 5-min averaging between the 10th and 15th min (T1) and 40th and 45th min (T2). For a similar HR (157±3 bpm…
Sex differences on peak oxygen uptake in heart failure
2019
Women represent nearly half of the adult heart failure (HF) population and they remain underrepresented in HF studies. We aimed to evaluate the evidence about peak oxygen uptake (peak VO2) for clinical stratification in women with HF. This narrative review summarizes (i) the evidence endorsing the value of cardiopulmonary exercise testing for clinical stratification and phenotyping HF population; (ii) the determinants of a person’s functional aerobic capacity to understand predicted values for patients with chronic HF; and (iii) sex differences on peak VO2 data in different forms of HF. Lastly, based on existing data in patients with HF, we provide a perspective on how to improve existing g…
VO2max Characteristics of Elite Female Soccer Players, 1989–2007
2013
Purpose:To quantify VO2max among female competitive soccer players as a function of performance level, field position, and age. In addition, the evolution of VO2max among world-class players over an 18-y period was quantified.Methods:Female players (N = 199, 22 ± 4 y, 63 ± 6 kg, height 169 ± 6 cm), including an Olympic winning squad, were tested for VO2max at the Norwegian Olympic Training Center between 1989 and 2007.Results:National-team players had 5% higher VO2max than 1st-division players (P = .042, d = 0.4), 13% higher than 2nd-division players (P < .001, d = 1.2), and 9% higher than junior players (P = .005, d = 1.0). Midfielders had 8% higher VO2max than goalkeepers (P = .048, d …
Influence of aquatic training on the motor performance of patients with haemophilic arthropathy
2009
Thirteen patients with haemophilia A took part in this study voluntarily. They underwent an aquatic training programme over a 9-week period (27 sessions; three sessions per week; 1 h per session). Their motor performance was assessed by the following cardio-respiratory and mechanical variables before and after the training programme: oxygen uptake (VO(2), mL min(-1)), relative oxygen uptake (rel VO(2), mL min(-1).kg(-1)), carbon dioxide (CO(2), mL min(-1)), respiratory quotient (R), heart rate (bpm) and the distance covered in 12 min (the Cooper test, m). Nine patients successfully completed the intervention and measurement protocols without bleeding or other adverse events. After the propo…
Time Course of Neuromuscular Alterations during a Prolonged Running Exercise
2004
PLACE, N., R. LEPERS, G. DELEY, and G. Y. MILLET. Time Course of Neuromuscular Alterations during a Prolonged Running Exercise. Med. Sci. Sports Exerc., Vol. 36, No. 8, pp. 1347–1356, 2004. Purpose: This study investigated the time course of contractile and neural alterations of knee extensor (KE) muscles during a long-duration running exercise. Methods: Nine well-trained triathletes and endurance runners sustained 55% of their maximal aerobic velocity (MAV) on a motorized treadmill for a period of 5 h. Maximal voluntary contraction (MVC), maximal voluntary activation level (%VA), and electrically evoked contractions (single and tetanic stimulations) of KE muscles were evaluated before, aft…
Age affects the metabolic rate of insect brain.
1984
Abstract Brains of adult insects can be isolated and studied vitro. In female blowflies the oxygen uptake of the brain is age dependent. A steady increase is followed by a precipitous decrease around the middle of the life span. These changes are accompanied by alterations of mitochondrial structure and deposits of lipofuscin-like material.
Recent advances in machine learning for maximal oxygen uptake (VO2 max) prediction : A review
2022
Maximal oxygen uptake (VO2 max) is the maximum amount of oxygen attainable by a person during exercise. VO2 max is used in different domains including sports and medical sciences and is usually measured during an incremental treadmill or cycle ergometer test. The drawback of directly measuring VO2 max using the maximal test is that it is expensive and requires a fixed and controlled protocol. During the last decade, various machine learning models have been developed for VO2 max prediction and numerous studies have attempted to predict VO2 max using data from submaximal and non-exercise tests. This article gives an overview of the machine learning models developed over the past five years (…
The effect of prolonged thermal stress on the physiological parameters of young, sedentary men and the correlations with somatic features and body co…
2019
Little is known about the effect of prolonged thermal stress on the physiological parameters of young and sedentary men. The aim of the study was to determine the effect of prolonged thermal stress on the physiological parameters of young men and the correlations with somatic features and body composition parameters. Forty-two sedentary men aged 20.24 ± 1.68 years were exposed to 10-, 12- and 14-minute sauna sessions (temperature: 90-91 °C; relative humidity: 14-16%). The participants' body composition parameters were determined pre-sauna exposure, and their body mass and blood pressure were measured pre and post-sauna treatment. Physiological parameters were monitored during each sauna ses…