Many people are worried about doing situps after having their navels pierced due to a myth that you can ruin your belly button ring with the exercise. Normal exercise is perfectly safe after piercing your navel. Simply keep your piercing clean and avoid tight clothing, so it doesn't irritate the piercing while it's healing. Consult the piercer and your doctor if your piercing shows signs of infection.
Lie on the floor, flat on your back. You may consider placing a padded mat underneath you for comfort.
Pull your shirt up over your navel piercing. Do this if it is still new and sore. Once the pain of the piercing has subsided and the movement of your shirt no longer irritates you, you can leave your shirt in place.
Place your hands underneath your head, behind your ears. You should not interlace your fingers behind your head.
Put your feet on the floor, shoulder-width apart. Consider having a spotter hold your feet in place throughout your situp.
Push your lower back down toward the floor. Use your abdominal muscles to lift your upper body into a sitting position. Do not use your arms to help you through your situp. Repeat until you have completed your situp routine.
Clean your piercing after exercising by mixing 1/4 teaspoon noniodized sea salt with 1 cup of warm bottled water. Soak the piercing twice a day for 10 minutes, then wash with antibacterial soap.