The primary advantage of high-intensity interval training (HIIT) is its effectiveness in improving cardiovascular fitness in a shorter time compared to traditional exercise. HIIT alternates short, intense bursts of activity with brief rest or lower-intensity periods, boosting metabolism and maximizing calorie burn in a condensed timeframe. This training method can promote muscle retention while promoting fat loss. Furthermore, HIIT is versatile and can be tailored to various fitness levels, making it an accessible option for many individuals looking to improve their overall fitness.