Search results for "Respiratory exchange ratio"
showing 7 items of 17 documents
Differences in cardiorespiratory and neuromuscular responses between voluntary and stimulated contractions of the quadriceps femoris muscle.
2006
The aim of this study was to compare respiratory gas exchange variables and muscle fatigue between equal-intensity (i.e., same force output) electrostimulated and voluntary contractions of the quadriceps muscle (46+/-10% of maximal voluntary force). Twelve healthy men served as volunteers. Oxygen consumption, ventilation and respiratory exchange ratio were recorded during the exercise bouts. Muscle fatigue was quantified as the exercise-induced reduction in maximal voluntary force. The average oxygen consumption (11+/-3 versus 8+/-2 mL min(-1)kg(-1)), ventilation (23+/-4 versus 16+/-2 L min(-1)) and respiratory exchange ratio (0.96+/-0.02 versus 0.85+/-0.01) were significantly higher during…
Near-normal aerobic capacity in long-term survivors after lung transplantation
2021
The clinical course of lung transplantation (LT) is diverse: some patients present chronic lung allograft dysfunction (CLAD) and progressive decline in pulmonary function, but others maintain normal spirometric values and active lives. Objectives The aim of this study was to elucidate whether long-term LT survivors with normal spirometry achieve normal exercise capacity, and to identify predictive factors of exercise capacity. Methods This was a cross-sectional multicentre study, where bilateral LT recipients who survived at least 10 years after LT, with normal spirometry, no diagnosis of CLAD and modified Medical Research Council dyspnoea degree ≤2 underwent cardiopulmonary exercise testin…
Cardiovascular and Autonomic Responses to a Maximal Exercise Test in Elite Youngsters
2017
AbstractTo analyze cardiovascular and autonomic responses in elite youngsters, 13 male cyclists (15.43±0.51 years) performed a graded-test until voluntary exhaustion. Oxygen consumption (VO2), blood lactate (BLa), arterial oxygen saturation (SaO2), respiratory exchange ratio (RER) and rating of perceived exertion (RPE) were collected, while heart rate (HR) was registered for heart rate variability (HRV) analyses, looking for linear and nonlinear comparisons. Cyclists reached maximal exertion [RPE: 19.14±0.94; BLa: 8.92±2.51 mmol.L−1; RER: 1.04±0.03; SaO2: 92.43±2.5%] and high-level performance (4.41±0.46 W·Kg−1; 60.77±6.87 ml·Kg·min−1) once over 95% of age-predicted HRmax. VO2 and RPE incre…
Ein Mikro-Atemstromventil für spontan atmende narkotisierte Kleintiere - A Respiratory Micro-Valve for Spontaneously Breathing Anaesthetized Small An…
1994
For the accurate functional analysis of the gas exchange in the lungs or evaluation of artificial oxygen carriers in spontaneously breathing anaesthetized small animals, we developed a new respiratory micro-valve. The body of the valve is made of aluminium, and the flaps are made of silicone rubber. The maximum flow rate in a rat measured with a pneumotachograph and the micro-valve was an average of 19.9 ml/s during inspiration, and 17.8 ml/s during expiration. The pressure measured in the tracheal tube was -0.85 during inspiration, and +0.39 cm H2O during expiration; the end-expiratory pressure in the tube was zero. In two experiments with anaesthetised rats lasting 4-5 hours, ventilation,…
Glucose 6-P dehydrogenase delays the onset of frailty by protecting against muscle damage.
2021
Background: Frailty is a major age-associated syndrome leading to disability. Oxidative damage plays a significant role in the promotion of frailty. The cellular antioxidant system relies on reduced nicotinamide adenine dinucleotide phosphate (NADPH) that is highly dependent on glucose 6-P dehydrogenase (G6PD). The G6PD-overexpressing mouse (G6PD-Tg) is protected against metabolic stresses. Our aim was to examine whether this protection delays frailty. Methods: Old wild-type (WT) and G6PD-Tg mice were evaluated longitudinally in terms of frailty. Indirect calorimetry, transcriptomic profile, and different skeletal muscle quality markers and muscle regenerative capacity were also investigate…
Home is the new gym: exergame as a potential tool to maintain adequate fitness levels also during quarantine
2020
Purpose With the coronavirus outbreak, the preventive measures include staying at home and isolation, increasing sedentary behaviours and risk for worsening of chronic diseases To explore alternative forms of home-based physical activity, the study aim was to evaluate physiological (heart rate [HR], respiratory exchange ratio [RER], oxygen consumption [ O2], energy expenditure [EE], metabolic equivalent task [MET]) and psychological (session rating of perceived exertion [sRPE], enjoyment) parameters of real (Zumba® class [ZC]) and exergame (Zumba® Fitness Rush [ZFR]) activities in relation to sex Methods Overall, 12 female (age: 24 7 ± 0 9 years) and 8 male (age: 25 3 ± 2 1 years) college s…
Do Obese Children Achieve Maximal Heart Rate during Treadmill Running?
2019
Objective: Maximal heart rate (HR) is commonly defined as the highest HR obtained during a progressive exercise test to exhaustion. Maximal HR is considered one of the criteria to assess maximum exertion in exercise tests, and is broadly used when prescribing exercise intensity. The aim of the present study was to compare peak HR measurements during maximal treadmill running and active play in obese children and adolescents. Design: Comparison of peak heart rate during active play vs. maximal treadmill running in 39 (7&ndash