Something that you can do to try not to build up your legs is to not have a calorie excess. A calorie excess is the point at which you're taking in additional calories than you are consuming. This doesn't mean starving yourself since it is vital to construct fit muscle to achieve your objectives of being conditioned. Additionally, your RMR (resting metabolic rate) will dial back assuming you starve yourself. This can make a calories overflow in any event, when you're not really eating anything by any stretch of the imagination. That being said, ensure you are not pigging out and gorging a lot too.