Bicycle crunches target the rectus abdominis, obliques, and hip flexors, making them a powerful core exercise. How to Perform: Lie on your back with hands behind your head. Lift your shoulders and bring one knee to your chest while twisting your torso. Alternate sides in a pedaling motion. Variations: 🔥 Slow Bicycle Crunches – Increase time under tension for better results. 🔥 Vertical Leg Bicycle Crunches – Keep legs extended vertically. 🔥 Weighted Bicycle Crunches – Hold a small weight for added resistance.