Related Experiment Video
Updated: Aug 17, 2026
Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise
Published on: February 20, 2017
Ventilatory efficiency is unchanged after physical training in healthy persons despite an increase exercise tolerance
A L Clark1, I Skypala, A J Coats
1Department of Cardiac Medicine, National Heart and Lung Institute, London, UK.
Background:
In chronic heart failure, exercise training results in an improvement in exercise capacity and a reduction in the ventilatory response to exercise. The effects of a physical training programme on the ventilatory response in healthy persons is not known.
Methods:
Metabolic gas exchange and ventilation were measured in 27 young healthy persons aged 31.4 +/- 7.6 years before and after a 19-week training programme of aerobic exercise; exercise was undertaken three times a week for 40 min. Ventilation, the slope of the relationship between ventilation and carbon dioxide production (VE-VCO2 slope) and the ventilatory equivalent for carbon dioxide were measured using respiratory mass spectroscopy. The peak expiratory flow rate in 1 s and forced vital capacity were also measured.
Results:
Mean +/- SEM peak oxygen consumption increased from 39.5 +/- 1.5 to 45.4 +/- 1.7 ml/kg/min(P<0.001). Exercise time increased from 817 +/- 188 to 896 +/- 186 s (P<0.001). The respiratory exchange ratio at peak exercise was slightly lower after training: 1.30 +/- 0.02 compared with 1.36 +/- 0.03 (P = 0.02). Ventilation at equivalent stages of exercise was unchanged by training. The VE-VCO2 slope did not change (24.52 +/- 0.67 before training, 25.01 +/- 0.80 after training; NS). There was no change in the ventilatory equivalent for carbon dioxide either at rest (38.6 +/- 1.4 compared with 36.2 +/- 1.1; NS) or at its lowest point (23.3 +/- 0.6 compared with 22.9 +/- 3.2; NS). Neither exercise capacity nor the training response correlated with any of the measured ventilatory variables.
Conclusion:
In contrast to the situation in patients with chronic heart failure, there is no relationship between ventilatory variables and exercise capacity in healthy persons and no change in ventilatory performance as a result of physical training.
Related Concept Videos
01:24Respiratory Capacities
One key metric is the Inspiratory Capacity (IC), which represents the maximum amount of air that can be inhaled with full effort. IC is calculated by summing the tidal volume and inspiratory reserve volume, typically ranging from 2.4 to 3.6 liters.
The Functional Residual Capacity (FRC) represents the air in the...
01:27Exercise and Muscle Performance
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
01:17Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be met...
01:20Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
01:19Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
01:22Respiratory Volumes and Capacities