. ♪ >> reporter: 17-year-old mattie gardener is one of the best all-star cheerleaders in the country.>> competitive cheer lead something really more action-packed and more difficult than high school cheerleading. to me, it is my passion. it became my sport. and now it's my life and it's what i do and it's pretty much who i am. >> reporter: she trains year round at cheer extreme in north carolina. one of the largest and most elite all-star cheerleading gyms. >> it is a big commitment to be here every day for three to four hours. i'm doing homework in the car on the way here, i'm doing homework in practice breaks. i'm taking four ap classes so i really set high goals for myself and i think cheerleading has really taught me that, too, don't settle for second-best. >> reporter: do you feel like you've had to sacrifice any of your teenage years for this sport if. >> i wouldn't want to be anywhere else honestly. i mean this is what i love to do. >> reporter: her coach, courtney poe, says the dedication on mattie's team is as intense as their practices. >> more than 50% of the team live two