In a 4-zone model for cardiorespiratory training, how is zone 2 defined in terms of intensity?

In the 4-zone model for cardiorespiratory training, zone 2 is defined as the intensity level that falls from VT1 (ventilatory threshold 1) to the midpoint between VT1 and VT2 (ventilatory threshold 2).

This zone represents a moderate intensity level where the body primarily relies on aerobic energy systems but is still working hard enough to push towards a higher intensity. Training in this zone can enhance the body’s ability to utilize oxygen more efficiently, improve endurance, and optimize overall cardiorespiratory fitness.

By focusing on this definition, trainers and clients can accurately identify the appropriate heart rates or perceived exertion levels needed to engage effectively in zone 2 training. This helps facilitate building a solid aerobic base and prepares the body for higher intensity training that occurs in zones 3 and 4, which are defined by more demanding exertion levels.