To improve cardiovascular fitness, what is the minimum time that one should engage in exercise at the target heart rate zone?

Engaging in exercise for at least 20 minutes in the target heart rate zone is essential for improving cardiovascular fitness. This duration allows the body to adequately adapt to the cardiovascular demands of the exercise, facilitating improvements in heart efficiency, increased stroke volume, and enhanced oxygen delivery to muscles. Research supports that 20 minutes is often considered a minimal threshold for developing aerobic capacity, as it is long enough for the body to enter a state where it can effectively increase its endurance and overall cardiovascular health.

While shorter durations, like 10 minutes, may contribute to some fitness improvements, they are generally not sufficient for significant cardiovascular adaptations. Sessions longer than 20 minutes can indeed provide greater benefits, contributing to higher levels of fitness and endurance, but 20 minutes is recognized as a practical and achievable starting point for most individuals looking to enhance their cardiovascular health.