Question

Why does ventilation increase non-linearly (break away) with increasing intensity of

exercise?

Does exercise training affect the "ventilatory break point"?  If so, how?

Answer 1

Ventilation increase with increasing intensity of exercise because there is a rise in the tidal volume (means the lung volume representing the normal volume of air between normal inhalation and exhalation) and respiratory rate to meet increased oxygen demand.With every breath oxygen and carbon dioxide are exchanged.When the need of oxygen increases during exercise,the rate of respiration can change dramatically.In this situation oxygen is needed to burn calories more efficiently.So that the blood picks up oxygen in the lungs and demand for oxygen increases and lugs must work harder and also bringing in more oxygen to supply the working muscles.In this case there is a decrease in inspiratory reserve volume.

Yes,exerice training affect the venilatory break point because it will increase the lactate thresold.The body will build a better tolerance to the effects of lactic acid over time during training.The lactate thresold is a useful measure for deciding exerice intensity of training and racing in endurance sports but varies between individuals and can be increased with training.