This exercise targets: abdominal muscles For this exercise, you will need: an exercise mat Lie flat on your back with your head and shoulders resting on the exercise mat. Straighten your legs, and “lock” your knees. Point your toes forward, and put your hands under your butt with your palms facing down. Raise your legs to the point they form a straight angle with your body. Return your legs to the starting position and repeat. Tips: Exhale during the effort or lifting phase and inhale during the lowering phase. Push the small of your back down into the floor to isolate your abdominal muscles better. Remember to keep your legs as straight as possible. Recommendation for beginners and people with back problems: bend your knees slightly. Advanced: Tuck your chin into your chest and perform the exercise more slowly. Advanced: Hold a dumbbell between your feet to increase the difficulty level, but be careful not to drop it. Beginners: 10 repetitions Intermediate level: 15 repetitions Advanced level: 20 repetitions