According to the material, VO2 max tends to increase with age.

• A. It increases with age
• B. It decreases with age
• C. It remains constant with age
• D. It fluctuates unpredictably with age

Answer: (A)

VO2 max generally decreases with age, due to changes in both the heart’s capacity to pump blood and the muscles’ ability to use oxygen. As people get older, maximal heart rate tends to decline, and stroke volume at peak exercise can fall, reducing the overall cardiac output available during intense effort. At the same time, skeletal muscles often show reduced mitochondrial density and oxidative enzyme activity, along with decreased capillary density, which lowers the muscles’ rate of oxygen extraction. All these factors together cause a gradual drop in VO2 max over the adult years. Regular endurance training can slow this decline and help maintain a higher VO2 max for longer, but the overall trend with aging is downward.