Ventilatory threshold is introduced in the ACE 4th edition Personal Trainer Manual as a way to measure a client’s intensity during exercise. Vt1 and VT2 play a role in the ACE Integrated Fitness Training Model, specifically as transition points between zones 1, 2 and 3 of cardiovascular training.

The cardiovascular system. We’ve all got one. We all know circulation of blood is fundamental to our survival. But what is the primary purpose of the cardiovascular system? And why is it so important?