MILFORD — A room full of Woodland Elementary School students watched in awe Tuesday afternoon as 17-year-old Seamus Stoker whipped a dozen lavender-colored cups in and out of pyramid-shaped stacks.

Editor's note: This segment was rebroadcast on Sept. 30, 2025. Click here for that audio. In the early 2000s, thousands of U.S. schools had their students race the clock to stack cups in gym class.

Blink and you might just miss it. The blur of crisscrossing hands and zigzagging neon cups is probably the weirdest organized sport you’ve never heard of. Dubbed sport stacking, this rapid-fire ...