Last year, the two women told police that Rigo Herrera, 22, of Bloomington, had sexually assaulted them at an undisclosed gym in Fontana.
He was arrested in November 2017 and then released as investigators looked for more evidence.
Earlier this month, the San Bernardino County District Attorney's Office issued an arrest warrant for Herrera.
Herrera does not work for the gym anymore and is believed to be unemployed.