Crunches are a great exercise to get a flat and toned abdomen, as long as they are well executed.
How? Lie in supine position, with your back completely adhering to the ground; bend your knees and keep your feet on the floor. You can place your hands either behind your head or cross them in front of your chest: in both cases, it is very important that your neck doesn’t make any effort. The most common mistake is moving the head forward, iperflecting it.
From this position, lift your shoulders and upper back slightly by contracting your abs. Stay at the peak for 1 to 5 seconds, and then go back to the starting position. Remember to exhale as you go up and to inhale as you go down.
Do at least 4 series of 20 abs contractions, pausing for 30 seconds after each series. At the end, maintain the peak for one minute.
Attention: Your lower back must always adhere to the ground. Conversely, you will be making an incorrect execution.
Tip: lifting your back off the floor just a little is enough to do a good exercise: forcing the movement would not make the exercise more effective, but may cause back strain. Also, do not try to lift more by using your neck’s muscles, which may cause useless pains or lesions. In this case, it can be helpful to place your hands behind your head to sustain it, keeping your elbows level with your ears.
Variation: repeat the exercise with your knees bent at 90 degrees and then with your legs straightened upwards, perpendicularly to the ground or slightly forward. To further increase the complexity of the exercise, you can execute all the exercises holding a weight on your chest.