These simple exercises you can do at home and you can do it whenever you want and wherever you need.
One needs only to follow these instructions:
Straighten and separate the legs wide hips. Bend to the position where the knees will be below 90 degrees. From that position corrected from the outside the left leg to the side, and then do the same with his right. Repeat the exercise 30 times.
From half bent condition corrected with your left foot back, and hands discard them forward. Return to original position and repeat the same with the other leg. Each leg individually makes a series of 30 repetitions.
Lie on your stomach and then lift the shoulders and knees. One foot constantly holds in the air so that you do circular movements that will repeat 30 times. Repeat the same with other leg.
After you tweak these 3 exercises, go to the latter. It consists of a side lying down and raising your feet for which you need a good strength and fitness.