The Wall Sit is a simple yet brutally effective isometric exercise that targets the quads, glutes, and core. It involves holding a seated position against a wall without support, building endurance and mental toughness.

To perform, stand with your back against a wall and slide down until knees are at 90 degrees. Keep your feet flat, shoulders back, and core engaged. Hold for time while maintaining steady breathing.

This exercise builds muscular endurance in the lower body, improves posture, and challenges mental resilience. It’s excellent for athletes who need stability under fatigue, such as runners, skiers, and HYROX competitors.

Common mistakes include setting knees past toes or dropping too low. Adjust foot position to keep the knees above the ankles. To increase difficulty, add a weight plate or extend the arms.

In RB100 programming, aim for a 100-second wall sit challenge to test pure leg endurance and focus.