As the school year begins, fields, courts and pools fill with young athletes eager to return to practice. For many, that excitement comes with a rapid increase in fitness training, which places new demands on growing bodies.

It's a time when many preventable injuries occur, according to Dr. Nirav Pandya, a pediatric orthopedic surgeon and the chief of sports medicine at UCSF Benioff Children's Hospitals.

"Kids often go from relatively unstructured activity to practices that are much more intense," Pandya said. "If they haven't prepared for that increase, they're more likely to develop injuries. The encouraging part is that many of those injuries can be prevented."

Pandya studies injury prevention and healthy athletic development. His research has helped inform national recommendations encouraging young athletes to participate in a variety of sports, as well as the relationship between youth sports participation and professional athlete injury risk in the NBA and NFL.