Born in Brooklyn, New York of Puerto Rican extraction, the 5'2" Masino won her pro card by winning the lightweight class at the 1995 NPC Nationals. She competed as a professional through 2007, and was the 2003 Night of Champions winner.

Starting from early 1996, Masino was featured in various prominent fitness and bodybuilding magazines. She was a two-time centerfold in Flex Power & Sizzle and voted the "sexiest Bodybuilder alive" by Iron Man magazine. She was also included in Flex's 1997 Annual Swimsuit issue and in their Fantasy Lingerie issue. In 1997, along with her then-husband and trainer Robert Masino, she founded Muscle Elegance, a magazine that features erotic pictorials of female bodybuilders and where Denise is featured as the main model. The magazine also produces a line of videos and the website Muscle Pinups.

Her feature film debut in the cultish vampire movie, Blood + Kisses (originally titled Kiss of the Vampire as shown in trailers), premiered in film festivals in 2005, but so far remains unreleased. She is currently featured in the documentary feature, "Adventures of Miss Fit," which had its film festival premiere in 2016.