Crunches
How to do it : -
Lie on your back on a mat, with your knees perpendicularly bent and your feet against the ground. Place your hands you temples. ( This will be your start position )
Curl your chest towards your knees while contracting your abs to lift your shoulders, keeping your lower back on the mat.
At the top of the move, pause and compress/tense your abs and slowly return the start position.
Planks
How to do it : -
Hold your body in a straight line from head to heels, your arms should be bent and directly under your shoulder.
Your body should be kept straight the whole time, hold this position as long as possible.