Spot Reduction Myth
Contrary to what the infomercials suggest there is no such thing as spot reduction. Fat is lost throughout the body in a pattern dependent upon genetics, sex (hormones), and age. Overall body fat must be reduced to lose fat in any particular area. Although fat is lost or gained throughout the body it seems the the first area to get fat, or the last area to become lean, is the midsection (in men and some women, especially after menopause) and hips and thighs (in women and few men). Sit-ups, crunches, leg-hip raises, leg raises, hip adduction, hip abduction, etc. will only exercise the muscles under the fat.
Right, I think all girls should be aware of those factors from very early stage of their life. They all need to know that there is no short cut way to lose weight quickly. If they follow any short cut way then they are just unintentionally putting their life in danger.
As a trainer, I would like to suggest to make their own workout routine by themselves or follow advice of their trainer.