High-knees is a dynamic exercise that involves running in place while lifting your knees as high as possible. This movement engages the core, legs, and hip flexors, promoting cardiovascular fitness and improving agility. It is often used in warm-up routines or as part of high-intensity interval training (HIIT) workouts. To perform high-knees, stand with your feet hip-width apart and begin jogging in place. As you jog, drive your knees up towards your chest, alternating legs quickly. Aim to keep a brisk pace, and use your arms to help maintain momentum. This exercise can be modified for different fitness levels by adjusting the speed or height of the knees.