Bicycle Crunch

Bicycle crunches are the best abdominal exercises to activate the rectus abdominus (long flat muscle that extends vertically between the pubis, fifth, sixth and seventh ribs) according to a study done at the San Diego State University which also compared 12 other popular abdominal workouts.

In order to complete this exercise lie flat on the floor with your lower back pressed to the ground and contract your core muscles. With your hands gently holding your head, lift your knees to about a 45-degree angle. Slowly, at first, go through a bicycle pedal motion. Alternate touching your elbows to the opposite knees as you twist back and forth. Breathe evenly throughout the exercise.