Simple exercise to work abdominal muscles at home.
Stand straight, with your feet shoulder width apart, knees are slightly bent.
Arms bent at the elbows, hands behind your head.
As you exhale crunch, bringing your upper body towards your waist.
Keep your lower back stationary.
As you exhale return to the starting position.
This exercise can be performed in a standing version and also in a seated version. In this case you should seat on your knees.
Keep your hips and legs stationary to make your abs work at the maximum.
You can use an additional weight if this exercise becomes too easy for you.