ESPN's Brian Windhorst says it was like that Nike commercial where hundreds of people follow LeBron on a run through Miami.
"One mid-morning this week along Copacabana Beach with the sun already burning the sand, LeBron James ran down the coastline as a real-life Nike commercial unfolded behind him, joggers surprised to see a celebrity lining up to run with him."
Globo Esporte has photos of the morning jog. For the record, it looks like only a few people joined LeBron on his run and everyone else was taking videos (some of which are below).
LeBron was joined by Tristan Thompson, Dion Waiters, and a few other Cavaliers players. They were there to play an exhibition game against the Miami Heat.