Stacking may just be the fastest growing sport in the country.
The competitions take place across the country and features participants stacking cups on top of each other as fast as they can without any of them falling over.
The first player or team to stack the cups and then take them down as fast as humanly possible wins the match. The cups are specially designed to avoid sticking to each other.
At a recent competition in San Francisco, "stackers" were as young as 6 and facing off in singles and doubles matches, as well as relay events.
“Team building, sportsmanship — all those things that teacher's really love — is that it gives opportunity and we've seen them blossom,” Jamie Limberg a tournament official, told Inside Edition.
“It’s fun to watch,” parent Sarah Altschuler told Inside Edition. “They work as a team try to motivate each other.”
The kids work up quite a sweat and experts say speed stacking improves hand-eye coordination by 30 percent.
“Elevated heart rate, perspiration, why wouldn’t it be called a sport?” Shelly Rabe, another tournament official, told Inside Edition.