What is the goal of training for oxygen utilization?

• A. Increase anaerobic threshold and oxidative capacity by increasing capillary density around muscle fiber, enzyme activity, and number of mitochondria in muscle cell
• B. Increase heart rate during workouts
• C. Decrease mitochondria in muscle cells
• D. Increase only muscle fiber size

Answer: (A)

Training to improve oxygen utilization aims to boost the body's ability to deliver and use oxygen in the muscles, so you can produce energy aerobically for longer and at higher intensities. The best way to achieve this is by building structures inside the muscle that support aerobic metabolism: more capillaries surrounding each muscle fiber to shorten the distance oxygen has to diffuse to reach working cells and to help remove byproducts; more mitochondria inside muscle cells to provide more sites for the oxidative pathways that generate ATP; and greater activity of oxidative enzymes that drive these aerobic reactions. Together, these adaptations increase oxidative capacity and raise the threshold at which fatigue from lactate begins to limit performance, enabling you to sustain harder efforts longer, which is crucial for rowing endurance.

Raising heart rate during workouts is a physiological response to exercise, not the direct goal of improving oxygen utilization. Reducing mitochondria would decrease oxidative capacity, which is counterproductive. Increasing only muscle fiber size targets strength/hypertrophy and does not specifically enhance the muscles’ ability to use oxygen efficiently.