Which adaptation enhances buffering capacity during high-intensity exercise?

• A. Increased fat oxidation
• B. Increased stroke volume
• C. Decreased blood volume
• D. Increased buffering capacity

Answer: (D)

Buffering capacity is about how well the body can neutralize the hydrogen ions that build up during intense exercise, helping to keep pH from dropping too quickly and delaying fatigue. Training can boost this capacity by increasing the amounts of buffers in the body, such as carnosine in muscles and bicarbonate in the blood, which together improve the ability to neutralize excess acidity. When buffering capacity increases, performance is better preserved under high-intensity efforts because the muscles can work at higher intensities for longer before acidosis limits function. The other options don’t directly enhance the body's acid‑base buffering systems: altering fat oxidation changes fuel use, changing stroke volume affects oxygen delivery rather than pH balance, and decreasing blood volume would actually reduce buffering potential.