Bicycle crunch: Lie down with your back pressed onto the floor. Bring your hands behind your head. Starting with your legs bent at a 45-degree angle, bring the right knee into the chest while straightening out your left leg. At the same time, rotate your top half so your left elbow goes to your right knee, then switch to the other side. Repeat for one minute,three times a day.
The boat: Sit on the floor, with your knees bent and feet flat and tilt back, extending your legs so your body forms a right angle. Pull your abs in to balance. Extend your arms at shoulder height past your knees. Hold for five slow breaths and return to your starting position. Repeat five times a day.
The plank: Lie face down then lift yourself up on to your toes and forearms, with your elbows bent at 90 degrees. Keeping your core muscles -— your stomach and bottom — tight and your legs straight, hold for 10 seconds. Repeat three times a day, gradually building to 40 seconds each.