Which statement best contrasts adaptations from endurance training and resistance training?

Which statement best contrasts adaptations from endurance training and resistance training?

• A. Endurance training increases mitochondrial density, capillary density, and oxidative enzymes; resistance training increases muscle cross-sectional area, neural drive, tendon stiffness, and bone density.
• B. Endurance training increases bone density and neural drive; resistance training increases mitochondrial density and capillary density.
• C. Endurance training increases neural drive; resistance training increases mitochondrial density only.
• D. Endurance training has no effect on mitochondria; resistance training increases capillary density only.

Answer: (A)

Endurance training primarily challenges the aerobic energy system, so the body adapts by increasing the machinery that makes and uses oxygen: more mitochondria in muscle fibers, greater capillary density to improve oxygen delivery, and higher levels of oxidative enzymes to speed fat and carbohydrate metabolism. Resistance training, on the other hand, stresses muscles to generate force, triggering hypertrophy (greater muscle fiber cross-sectional area), improvements in neural activation (better motor unit recruitment and firing), and remodeling of connective tissue and bone to handle higher loads—tendon stiffness and bone density increase. Because of these distinct targets, the statement that endurance trains mitochondria, capillaries, and oxidative enzymes, while resistance trains muscle size, neural drive, tendon stiffness, and bone density, best contrasts the two. The other options misstate where these adaptations occur or claim no effect on key tissues, which doesn’t align with how the body responds to these training stimuli.

Endurance training primarily challenges the aerobic energy system, so the body adapts by increasing the machinery that makes and uses oxygen: more mitochondria in muscle fibers, greater capillary density to improve oxygen delivery, and higher levels of oxidative enzymes to speed fat and carbohydrate metabolism. Resistance training, on the other hand, stresses muscles to generate force, triggering hypertrophy (greater muscle fiber cross-sectional area), improvements in neural activation (better motor unit recruitment and firing), and remodeling of connective tissue and bone to handle higher loads—tendon stiffness and bone density increase. Because of these distinct targets, the statement that endurance trains mitochondria, capillaries, and oxidative enzymes, while resistance trains muscle size, neural drive, tendon stiffness, and bone density, best contrasts the two. The other options misstate where these adaptations occur or claim no effect on key tissues, which doesn’t align with how the body responds to these training stimuli.