NASM Senior Fitness Specialist Practice Test 2025 – Complete Exam Prep

In the OPT (Optimum Performance Training) model, the strength level focuses on building muscle strength and power through higher loads and lower repetitions. When individuals have reached this stage, they are likely able to handle more intense training, which is appropriate for cardiorespiratory Zone 2.

Zone 2 is characterized by moderate-intensity exercise where the heart rate is elevated but clients can still talk comfortably. This zone is suitable for someone at the strength level of training because they have developed a foundation of strength that allows for higher workloads and can effectively support the demands of sustained moderate-intensity cardiovascular exercise. At this level, clients are also encouraged to improve their aerobic capacity, which enhances their endurance and overall fitness.

The other zones focus on different training intensities. Zone 1 is generally aimed at recovery and lower-intensity training, while Zone 3 and beyond push into higher intensity, which may not be suitable for individuals at the strength level who may not yet be conditioned for such high workloads. Thus, Zone 2 strikes the right balance for those who have moved beyond basic stability and endurance and are ready to enhance their cardiorespiratory fitness alongside their strength training.