If you are satisfying your body s need of aerobic exercise with your Volleyball practice, then do some light strength / weightlifting exercises four times a week and take care of what you eat. You can also try the Power Plate.
listen to the person who had jo-jo effect for 6 times. don t lose more than 4-5 kilos a month. or you ll be sorry. i can say that there is nothing more humiliating than to gain more weight than you lost.