Dynamics of ventilation and heart rate in response to sinusoidal work load in man
About: This article is published in Journal of Applied Physiology.The article was published on 1970-08-01. It has received 74 citations till now. The article focuses on the topics: Ventilation (architecture).
Citations
More filters
TL;DR: The exponential behavior of VE, VO2, and VCO2 in response to moderate exercise is best described by a model that incorporates only the second phase of the response.
Abstract: To determine the precise nonsteady-state characteristics of ventilation (VE), O2 uptake (VO2), and CO2 output (VCO2) during moderate-intensity exercise, six subjects each underwent eight repetition...
669 citations
TL;DR: Greater understanding of VO2 kinetics control and, in particular, its relation to the plasticity of the O2-transport/utilization system is considered important for improving the human condition, not just in athletic populations, but crucially for patients suffering from pathologically slowed VO2Kinetics as well as the burgeoning elderly population.
Abstract: Muscular exercise requires transitions to and from metabolic rates often exceeding an order of magnitude above resting and places prodigious demands on the oxidative machinery and O2-transport pathway. The science of kinetics seeks to characterize the dynamic profiles of the respiratory, cardiovascular, and muscular systems and their integration to resolve the essential control mechanisms of muscle energetics and oxidative function: a goal not feasible using the steady-state response. Essential features of the O2 uptake (VO2) kinetics response are highly conserved across the animal kingdom. For a given metabolic demand, fast VO2 kinetics mandates a smaller O2 deficit, less substrate-level phosphorylation and high exercise tolerance. By the same token, slow VO2 kinetics incurs a high O2 deficit, presents a greater challenge to homeostasis and presages poor exercise tolerance. Compelling evidence supports that, in healthy individuals walking, running, or cycling upright, VO2 kinetics control resides within the exercising muscle(s) and is therefore not dependent upon, or limited by, upstream O2-transport systems. However, disease, aging, and other imposed constraints may redistribute VO2 kinetics control more proximally within the O2-transport system. Greater understanding of VO2 kinetics control and, in particular, its relation to the plasticity of the O2-transport/utilization system is considered important for improving the human condition, not just in athletic populations, but crucially for patients suffering from pathologically slowed VO2 kinetics as well as the burgeoning elderly population.
423 citations
TL;DR: The sections in this article are: New Techniques for Studying Exercise Hyperpnea, Conceptual Development of Ventilatory Control Hypotheses, Cardiovascular Linkages, and Conclusion.
Abstract: The sections in this article are:
1
New Techniques for Studying Exercise Hyperpnea
1.1
Computerized Data Analysis
1.2
Systems Analysis of Dynamic Work-Rate Forcings
2
Behavior of Ventilatory Control System
2.1
Ventilatory Response to Incremental Exercise
2.2
Ventilatory Response to Constant-Load Exercise
2.3
Factors Affecting Ventilatory Response to Constant-Load Exercise
3
Conceptual Development of Ventilatory Control Hypotheses
3.1
Central Neurogenic Drive
3.2
Peripheral Neurogenic Drive
3.3
Neurohumoral Drive
3.4
Humoral Concepts
3.5
Cardiovascular Linkages
4
Conclusion
193 citations
TL;DR: An approach to the problem of organization in human action is presented and nonlinear properties of four subsystems of the human action system are described, which lead to the perceptual bottleneck.
182 citations
TL;DR: The sections in this article are: Steady State, Comparative Aspects of Gas Exchange, Control and Kinetics of Gas exchange in Muscle, and Conclusions.
Abstract: The sections in this article are:
1
Steady State
1.1
External Gas Exchange
1.2
Alveolar Gas Exchange
1.3
Blood O2-Carrying Capacity
1.4
Energy Cost of Blood Pumping
1.5
Cardiovascular Adjustments
1.6
Oxygen Utilization and its Limiting Factors
1.7
Comparative Aspects of Gas Exchange
2
Unsteady State
2.1
Pulmonary Gas-Exchange Transients
2.2
Cardiovascular Transients
2.3
Control and Kinetics of Gas Exchange in Muscle
3
Conclusions
119 citations