You shave your legs for many reasons; air resistance isn’t one of them. You should shave your legs before the race though. Here are the reasons you shave your legs:
1. Massage, it is really hard to massage your legs with oil when you have a forest growing from it. It is also a courtesy to the masseuse. She, or he, has plenty of people to massage, the smother the legs, the smoother her hands will be.
2. Crashing, if you do, yes it is easier to heal and quicker.
3. Clean look, it shows you care.