In which training stage would work intervals be performed just above VT1 and recovery intervals below VT1?

The correct answer is Stage 2 training because this stage specifically involves interval training strategies where work intervals are conducted just above the first ventilatory threshold (VT1) and recovery intervals are performed below VT1.

In Stage 2 training, clients engage in a moderate to high-intensity workout that helps improve their aerobic and anaerobic fitness. This is accomplished by alternating between periods of higher intensity, which challenges the cardiovascular system, and lower intensity recovery phases, allowing the body to recover while still maintaining an elevated heart rate.

This method of training optimally develops endurance and promotes improvements in both aerobic capacity and the ability to sustain higher intensity efforts over time. It is essential for personal trainers to understand these thresholds to effectively design training protocols that align with clients' fitness goals and capabilities.

In contrast, Stage 1 focuses on establishing a base of aerobic fitness primarily below VT1, and Stages 3 and 4 are designed for more advanced training techniques that push clients to perform consistently at or above their anaerobic thresholds.