When I was younger I read this book about superheroes. Its protagonist gained super speed during a childhood baseball game and knocked over the seating stand. It was kind of in a similar vein to the film Zoom.
Might it be Clarke Baldwin's My Baseball Teammates are Half Cheetah?
Chance Bradley wants to be starting pitcher for his town’s baseball team but he just can’t seem to get to that next level. He and his friends volunteer for a scientific experiment that is supposed to make them faster and stronger. Chance wakes up to a whole new way of life that involves super speed and some unexpected side effects. It’s a jungle out there in the baseball playoffs.
Found with a search for
book boy superspeed baseball