1.) Lie down, with your stomach on the floor and keeping both legs straight.
2.) Resting on your hands, push your body upwards.
3.) Bend your left leg, so that the foot is in front of your right hip (as in the first picture).
4.) Drop your body down to the ground (as in the second picture).
5.) You will feel the stretch in the front of the left hip.
6.) Hold the stretch for 35 seconds. Do not bounce. Just hold it.
7.) Swap your legs over and stretch the opposite side.
8.) Repeat this exercise 3 times, stretching both sides. Do it 3 times a day.