No matter which variations you follow, crunches have the advantage over sit-ups of being able to better target abdominal muscles. "Because the movement is smaller, you can control momentum more," ...

Bicycle crunches can be easily learnt ... Add more resistance to this exercise by holding a medicine ball or dumbbell with both hands. Twist the ball towards each knee when you do the crunch ...

than you would lying on your back doing sit-ups and crunches. This workout has the added benefit of using a dumbbell, increasing the resistance. Grab a dumbbell, and get ready for your obliques to ...

Lifting your head and shoulders to one side or the other or engaging in bicycle crunches by involving your legs will, too. These and other variations like ones involving free weights or resistance ...