scholarly journals Is the healthy respiratory system built just right, overbuilt, or underbuilt to meet the demands imposed by exercise?

2020 ◽  
Vol 129 (6) ◽  
pp. 1235-1256 ◽  
Author(s):  
Jerome A. Dempsey ◽  
Andre La Gerche ◽  
James H. Hull
Keyword(s):  
Respiratory System ◽  
Exercise Performance ◽  
Respiratory Muscles ◽  
Lung Parenchyma ◽  
Endurance Athletes ◽  
Pulmonary Vasculature ◽  
Blood Gas ◽  
Ventilatory Control ◽  
Response To Exercise ◽  
Homeostatic Response

In the healthy, untrained young adult, a case is made for a respiratory system (airways, pulmonary vasculature, lung parenchyma, respiratory muscles, and neural ventilatory control system) that is near ideally designed to ensure a highly efficient, homeostatic response to exercise of varying intensities and durations. Our aim was then to consider circumstances in which the intra/extrathoracic airways, pulmonary vasculature, respiratory muscles, and/or blood-gas distribution are underbuilt or inadequately regulated relative to the demands imposed by the cardiovascular system. In these instances, the respiratory system presents a significant limitation to O2 transport and contributes to the occurrence of locomotor muscle fatigue, inhibition of central locomotor output, and exercise performance. Most prominent in these examples of an “underbuilt” respiratory system are highly trained endurance athletes, with additional influences of sex, aging, hypoxic environments, and the highly inbred equine. We summarize by evaluating the relative influences of these respiratory system limitations on exercise performance and their impact on pathophysiology and provide recommendations for future investigation.

Breathless Legs? Consider Training Your Respiration

Physiology ◽  
2000 ◽  
Vol 15 (2) ◽  
pp. 101-105 ◽  
Author(s):  
Christina M. Spengler ◽  
Urs Boutellier
Keyword(s):  
Endurance Training ◽  
Endurance Exercise ◽  
Respiratory System ◽  
Exercise Performance ◽  
Healthy Subjects ◽  
Respiratory Muscles

The condition of the respiratory system is more important for endurance exercise performance of healthy subjects than hitherto assumed. Not only do respiratory muscles fatigue during intensive endurance exercise, but prefatigued respiratory muscles can also impair performance. In turn, respiratory endurance training can improve endurance exercise performance.

scholarly journals Acute effect of high-definition and conventional tDCS on exercise performance and psychophysiological responses in endurance athletes: a randomized controlled trial

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Gomes da Silva Machado ◽  
Marom Bikson ◽  
Abhishek Datta ◽  
Egas Caparelli-Dáquer ◽  
Gozde Unal ◽  
...  
Keyword(s):  
Exercise Performance ◽  
Controlled Trial ◽  
Lower Limbs ◽  
Endurance Athletes ◽  
Test Reliability ◽  
Whole Body ◽  
Time To Exhaustion ◽  
Small Ring ◽  
High Definition ◽  
Psychophysiological Responses

AbstractTranscranial direct current stimulation (tDCS) has been used aiming to boost exercise performance and inconsistent findings have been reported. One possible explanation is related to the limitations of the so-called “conventional” tDCS, which uses large rectangular electrodes, resulting in a diffuse electric field. A new tDCS technique called high-definition tDCS (HD-tDCS) has been recently developed. HD-tDCS uses small ring electrodes and produces improved focality and greater magnitude of its aftereffects. This study tested whether HD-tDCS would improve exercise performance to a greater extent than conventional tDCS. Twelve endurance athletes (29.4 ± 7.3 years; 60.15 ± 5.09 ml kg−1 min−1) were enrolled in this single-center, randomized, crossover, and sham-controlled trial. To test reliability, participants performed two time to exhaustion (TTE) tests (control conditions) on a cycle simulator with 80% of peak power until volitional exhaustion. Next, they randomly received HD-tDCS (2.4 mA), conventional (2.0 mA), or active sham tDCS (2.0 mA) over the motor cortex for 20-min before performing the TTE test. TTE, heart rate (HR), associative thoughts, peripheral (lower limbs), and whole-body ratings of perceived exertion (RPE) were recorded every minute. Outcome measures were reliable. There was no difference in TTE between HD-tDCS (853.1 ± 288.6 s), simulated conventional (827.8 ± 278.7 s), sham (794.3 ± 271.2 s), or control conditions (TTE1 = 751.1 ± 261.6 s or TTE2 = 770.8 ± 250.6 s) [F(1.95; 21.4) = 1.537; P = 0.24; η2p = 0.123]. There was no effect on peripheral or whole-body RPE and associative thoughts (P > 0.05). No serious adverse effect was reported. A single session of neither HD-tDCS nor conventional tDCS changed exercise performance and psychophysiological responses in athletes, suggesting that a ceiling effect may exist.

scholarly journals Cardiac and Pulmonary Vascular Remodeling in Endurance Open Water Swimmers Assessed by Cardiac Magnetic Resonance: Impact of Sex and Sport Discipline

2021 ◽  
Vol 8 ◽  
Author(s):  
Vanessa Martínez ◽  
María Sanz-de la Garza ◽  
Blanca Domenech-Ximenos ◽  
César Fernández ◽  
Ana García-Alvarez ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Pulmonary Artery ◽  
Open Water ◽  
Left Ventricular ◽  
Endurance Athletes ◽  
Cardiac Response ◽  
Pulmonary Vasculature ◽  
Exercise Induced ◽  
Pulmonary Remodeling ◽  
The Impact

Background: The cardiac response to endurance exercise has been studied previously, and recent reports have described the extension of this remodeling to the pulmonary vasculature. However, these reports have focused primarily on land-based sports and few data are available on exercise-induced cardio-pulmonary adaptation in swimming. Nor has the impact of sex on this exercise-induced cardio-pulmonary remodeling been studied in depth. The main aim of our study was to evaluate cardiac and pulmonary circulation remodeling in endurance swimmers. Among the secondary objectives, we evaluate the impact of sex and endurance sport discipline on this cardio-pulmonary remodeling promoted by exercise training.Methods:Resting cardiovascular magnetic resonance imaging was performed in 30 healthy well-trained endurance swimmers (83.3% male) and in 19 terrestrial endurance athletes (79% male) to assess biventricular dimensions and function. Pulmonary artery dimensions and flow as well as estimates of pulmonary vascular resistance (PVR) were also evaluated.Results:In relation to the reference parameters for the non-athletic population, male endurance swimmers had larger biventricular and pulmonary artery size (7.4 ± 1.0 vs. 5.9 ± 1.1 cm2, p < 0.001) with lower biventricular ejection fraction (EF) (left ventricular (LV) EF: 58 ± 4.4 vs. 67 ± 4.5 %, p < 0.001; right ventricular (RV) EF: 60 ± 4 vs. 66 ± 6 %, p < 0.001), LV end-diastolic volume (EDV): 106 ± 11 vs. 80 ± 9 ml/m2, p < 0.001; RV EDV: 101 ± 14 vs. 83 ± 12 ml/m2, p < 0.001). Significantly larger LV volume and lower LV EF were also observed in female swimmers (LV EF: 60 ± 5.3 vs. 67 ± 4.6 %, p = 0.003; LV EDV: 90 ± 17.6 vs. 75± 8.7 ml/m2, p = 0.002). Compared to terrestrial endurance athletes, swimmers showed increased LV indexed mass (75.0 ± 12.8 vs. 61.5 ± 10.0 g/m2, p < 0.001). The two groups of endurance athletes had similar pulmonary artery remodeling.Conclusions: Cardiac response to endurance swimming training implies an adaptation of both ventricular and pulmonary vasculature, as in the case of terrestrial endurance athletes. Cardio-pulmonary remodeling seems to be less extensive in female than in male swimmers.

A STUDY OF EXERCISE PERFORMANCE AND HEART RATE: THE RESPONSE TO EXERCISE OF A SMALL GROUP OF MANUAL WORKERS BEFORE AND AFTER RETIREMENT

1977 ◽  
Vol 6 (4) ◽  
pp. 232-237 ◽  
Author(s):  
E. JOAN BESSEY ◽  
P. H. FENTEM ◽  
I. C. MACDONALD ◽  
J. M. PATRICK ◽  
PATRICIA M. SCRIVEN
Keyword(s):  
Heart Rate ◽  
Small Group ◽  
Exercise Performance ◽  
Before And After ◽  
Response To Exercise

Effects of 3-day bed rest on physiological responses to graded exercise in athletes and sedentary men

2001 ◽  
Vol 91 (1) ◽  
pp. 249-257 ◽  
Author(s):  
J. Smorawiński ◽  
K. Nazar ◽  
H. Kaciuba-Uscilko ◽  
E. Kamińska ◽  
G. Cybulski ◽  
...  
Keyword(s):  
Lactate Concentration ◽  
Human Growth ◽  
Plasma Renin ◽  
Bed Rest ◽  
Peak Oxygen Uptake ◽  
Endurance Athletes ◽  
Norepinephrine Concentration ◽  
Before And After ◽  
Response To Exercise ◽  
Sedentary Subjects

To test the hypotheses that short-term bed-rest (BR) deconditioning influences metabolic, cardiorespiratory, and neurohormonal responses to exercise and that these effects depend on the subjects' training status, 12 sedentary men and 10 endurance- and 10 strength-trained athletes were submitted to 3-day BR. Before and after BR they performed incremental exercise test until volitional exhaustion. Respiratory gas exchange and heart rate (HR) were recorded continuously, and stroke volume (SV) was measured at submaximal loads. Blood was taken for lactate concentration ([LA]), epinephrine concentration ([Epi]), norepinephrine concentration ([NE]), plasma renin activity (PRA), human growth hormone concentration ([hGH]), testosterone, and cortisol determination. Reduction of peak oxygen uptake (V˙o 2 peak) after BR was greater in the endurance athletes than in the remaining groups (17 vs. 10%). Decrements in V˙o 2 peak correlated positively with the initial values ( r = 0.73, P < 0.001). Resting and exercise respiratory exchange ratios were increased in athletes. Cardiac output was unchanged by BR in all groups, but exercise HR was increased and SV diminished in the sedentary subjects. The submaximal [LA] and [LA] thresholds were decreased in the endurance athletes from 71 to 60%V˙o 2 peak ( P < 0.001); they also had an earlier increase in [NE], an attenuated increase in [hGH], and accentuated PRA and cortisol elevations during exercise. These effects were insignificant in the remaining subjects. In conclusion, reduction of exercise performance and modifications in neurohormonal response to exercise after BR depend on the previous level and mode of physical training, being the most pronounced in the endurance athletes.

Mathematical modeling of processes in the human respiratory system

2015 ◽  
Vol 9 (2) ◽  
pp. 0-0 ◽  
Author(s):  
Канунникова ◽  
A. Kanunnikova ◽  
Ивахно ◽  
N. Ivakhno ◽  
Федоров ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mass Flow ◽  
Respiratory System ◽  
Breathing Circuit ◽  
Stress Component ◽  
Respiratory Muscles ◽  
Axial Direction ◽  
Flow Diagram ◽  
Cylinder Wall ◽  
Human Respiratory System

Scientific relevance and purpose. This research looks at the urgent task of modeling the structure of the human respiratory system and processes occurring in it, in order to predict the changes in physiological parameters occurring under different mechanical actions. Results. This paper suggests mathematical model based on the description of equations of the mass flow and mass flow rate in the pulmonary channels in cases, when airways are branched in accordance with the prin-ciple of regular dichotomy with regard to the equations of work dynamics of the respiratory muscles and the ability to model different stresses in the breathing circuit, caused by trainers. The research examined the stresses generated by muscles in the radial and axial direction of the equivalent hollow cylinder, which represented the chest with regard to the elastic stress component in the cylinder wall and variable muscle stress in the circumfe-rential direction. The paper contains the results of mathematical modeling of breathing without stress, the graphs of volume and mass flow in lungs generations and pressure-flow diagram. Conclusions. The developed mathematical models enable more precise multi-parameter modeling of the dynamics of functioning of complex biotech system &#34;respiratory muscles trainer - human&#34;, which enables the implementation of the prediction of shifts of physiological and mechanical properties from the values of the normal process and to adjust the control actions on this basis

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