#4 – Bicycle Crunch
All you need is a floor for this one! We all have a floor, right? This all-rounder has been voted the single most effective ab exercise by researchers as it works the ab muscles harder than any other, working the upper and lower regions as well as the obliques to the side of our six-pack muscles. To do it, lie flat on the floor and hold your head in your hands, lifting your knees to 45 degrees. Move your legs as though you were pedalling a bicycle whilst touching your elbows to opposite knees as they come towards your chest, by twisting your torso. Breath steadily throughout the exercise and build up the number of repetitions as you improve. You should feel a really nice burn in your mid-section. Ensure you do the exercise slowly and deliberately to gain the most benefit from this one.