The retired Florida professor who invented Gatorade, the hydrating drink that created a multibillion-dollar sports beverage market, died on Tuesday at age 80, the University of Florida said.

Dr Robert Cade (picture) created the drink in 1965 to help rehydrate the school's athletes during games in Florida's punishing heat and named it after the university's mascot, the gator.

Gatorade became a worldwide success and spawned a generation of copycat sports beverages. It held an 81 per cent share of the $7.5 billion US sports drink market last year, according to Beverage Digest.

It has earned about $150 million in royalties for the school, including an average of $12.5 million annually over the last five years, spokesman Tom Fortner said.

"Dr Cade died peacefully this morning," Fortner said.

Bruce Kone, dean of the University of Florida's College of Medicine, said Cade had fought a long battle with kidney disease, an illness he specialised in.

"He was on dialysis," Kone told Reuters.

Cade, a former professor of medicine and physiology, signed a marketing deal decades ago and when the drink started selling, the university asked for rights, but Cade refused, according to published reports.

The university sued and eventually the parties reached an agreement to share profits.

Gatorade is now owned by Pepsico Inc.