In ELLE.com's series Unexpected Expert, we're going straight to the source to find out which items are actually worth your hard-earned cash.

Athletes look for any advantage to help them finish first—and that starts long before the competition ever does. Track icon Allyson Felix calls her motherahead of races, Serena Williams has to tie her shoe laces a certain way, and USWNT defender Crystal Dunn pumps up her teammates by DJing. For swimmers, there is one pre-race ritual that can make all the difference: Shaving. “Every little thing I do as a part of my pre-race ritual is in place to get me either physically or mentally ready for the starting blocks—and to put years of training together into a race,” swimmer Mallory Weggemann, who is currently competing at the Tokyo Paralympics, tells ELLE.com. “Shaving is a big part of that.”