Split jumps. High kicks. Sitting on someone's shoulders. Flying. Even the bravest of cheerleaders might quail the first time she's asked to do all that and more while on her period -- but as long as you're properly prepared, it ends up being no big deal. Wearing tampons is the most convenient solution, although some girls use menstrual pads as well.
Tampons for the Win
Tampons are the best solution for cheerleaders because they absorb the blood inside you, instead of waiting for it to leak out first -- the way menstrual pads do. Keeping the blood inside means no odors, and a much lower chance of a leak. You also have the option of wearing a thin pantyliner, a very thin menstrual pad, that might not show at all under your shorts or skirt as backup. If you find adult tampons uncomfortable, some companies make slender or teen-sized tampons.
Always Start Fresh
Whether you're using tampons or pads, ensure your period gear is sufficiently absorbent to handle your flow. Change your tampon or pad just before you hit the field; that way you know you're starting fresh. Keep extra supplies handy if you're experiencing a heavier than usual flow.
Going for a No-Show
Wearing dark-colored shorts can help conceal the outline of a menstrual pad under your skirt. If dark shorts and tampons aren't an option, wearing a second pair of shorts underneath your uniform shorts can help keep everything in place. And finally, if you need an ally to help you talk to your cheer coach about period issues and don't want to get your parents involved, ask the school nurse for help.