In a practice setting, it doesn’t matter if your underwear shows beneath your gymnastics leotard, except in matters of personal taste. In competition, however, judges will actually deduct points if your underwear is visible. It can be difficult to conceal underwear beneath your leotard and, for this reason, many gymnasts go without while competing. If you feel uncomfortable going without, there are some tricks and tips that can help you keep your underwear from showing.
Wear flesh-toned thongs, high-cut panties or Y-back underpants. These types of underwear will not be visible if the leotard rides up during your routine. In fact, these panties are also not likely to show visible panty lines beneath your leotard.
Wear a tube-style bra to prevent bra straps from showing at the top of your leotard. If your leotard has a keyhole or scoop back, wear a backless bra.
Use butt glue to keep your leotard and underwear in place. Butt glue is a body adhesive that was originally used in beauty pageants to keep the swim suits from riding up. Gymnasts also use this product to hold their leotards in place. Apply the adhesive to your skin and press the edge of the leotard onto the adhesive.