How long does it typically take for an athlete's cardiovascular system to normalize after moving from sea level to high altitudes?

The time it typically takes for an athlete's cardiovascular system to normalize after moving from sea level to high altitudes is around 10 to 14 days. This period is necessary due to the body's need to adapt to lower oxygen levels found at higher elevations. During this time, physiological changes occur, such as increased red blood cell production, adjustments in breathing rate, and alterations in blood flow to maintain oxygen delivery to the muscles.

These adaptations are critical as they help improve performance and overall acclimatization at altitude. An athlete may experience symptoms of altitude sickness and decreased performance until these adaptations are fully realized, which is why the process spans more than just a few days. The other options suggest shorter or longer time frames that do not accurately reflect the standard physiological adaptations required by the body when transitioning to higher altitudes.