The plank is a simple yet highly effective isometric exercise for core stability. By holding a static position with the body in a straight line, it strengthens the abdominals, obliques, lower back, and even the shoulders and glutes. Unlike crunches, the plank builds functional stability that transfers to lifts, running, and daily posture.

To perform, set up in a forearm or push-up plank position, ensuring elbows are under shoulders, hips are level, and body forms a straight line from head to heels. Hold the position while bracing the core and glutes.

Planks can be progressed by increasing duration, adding instability (e.g., stability ball), or including dynamic variations like plank shoulder taps. They’re scalable for beginners and advanced athletes alike.

RB100 athletes may aim for a 100-second plank challenge, testing both strength and mental focus. The plank is also a safe rehabilitation exercise for those rebuilding core stability.