The exercise that you can do for your abs is the bicycle crunch. It helps to target rectus abdominis and obliques muscles at the same time. If you do 20 crunches in a minute, you will burn 3 calories per minute.
Step 1: Lie on your back on the ground with legs stretched and arms resting by your side.
Step 2: Put your hand behind your head and try to lift your shoulders and upper back off the ground.
Step 3: Bend your right knee and bring it towards your chest. At the same time, move your left elbow towards the centre. Your knees and elbow should meet in the middle of the body.
Step 4: Repeat the same with the other elbow and knee.