CSSD Practice Exam 2026 – Complete Study Resource

Endurance training leads to specific cardiovascular adaptations that enhance the body's efficiency during prolonged physical activity. One of the key adaptations is an increase in oxidative enzymes. These enzymes play a crucial role in the metabolic pathways that utilize oxygen to produce energy, particularly in muscle cells. A higher concentration of oxidative enzymes facilitates improved aerobic metabolism, enabling the body to generate more energy from fats and carbohydrates during endurance activities.

This adaptation allows athletes and individuals who engage in regular endurance training to perform longer and at a higher intensity without experiencing fatigue as quickly as those who are untrained. The increase in oxidative enzymes also correlates with improvements in overall aerobic capacity, as the muscles become more adept at utilizing the oxygen delivered to them.

Other options, while relevant to cardiovascular adaptations, do not accurately reflect what generally occurs with endurance training. Increased red blood cell count can happen but is not as immediate or direct as the change in oxidative enzymes. Decreased mitochondria and reduced myoglobin levels, on the other hand, are not typical adaptations associated with endurance training and would actually be counterproductive to the goals of enhancing aerobic performance.