Richard Simmons.Evan Hurd Photography/Sygma/GettyFitness guru Richard Simmons died on Saturday, one day after his 76th birthday.TMZ first reported that law enforcement said he passed naturally, with no foul play suspected.Simmons was known for his energetic personality and weight-loss videos.Richard Simmons, the iconic fitness personality, has died at the age of 76.TMZ first reported the news, indicating that no foul play was suspected.