Songfacts®:

• The fitness craze collided head-on with pop music in 1981 with Olivia Newton-John's "Physical," the biggest song of that year. In 1982 Diana Ross celebrated the buff and brawny in "Muscles," where she makes it clear that guys need more than understanding to get her attention, they also need bulging biceps. (In real life, Ross was married to a businessman named Arne Naess, Jr., who didn't appear to spend much time in the gym.)
  
  "Muscles" did for weight training what "Physical" did for cardio. A lot of guys suddenly started using their gym memberships after the song came out.
• "Muscles" was written and produced by Michael Jackson just before he reached superstar status with this Thriller album. He and Diana Ross were both signed to Motown Records and had an enduring friendship. When The Jackson 5 debuted in 1969, Ross was dispatched to promote them, implying that she discovered the group. In 1978, they appeared together in the movie The Wiz.
  
  It was Jackson who approached Ross about the song; it was a way of thanking her for her support and friendship over the years.
• As reveled in Michael Jackson's autobiography Moonwalk, "Muscles" was the name of his pet snake, a boa constrictor he would sometimes wear around his neck. Jackson enjoyed exotic pets - he also had a chimpanzee named Bubbles.
• The song was released in 1982 shortly before Michael Jackson issued "The Girl Is Mine," his Paul McCartney duet that was the first single from Thriller. Most of the songs Jackson wrote he recorded either solo or with his brothers in The Jacksons; "Muscles" was the only big hit he wrote but didn't perform on (he also co-wrote the star-packed "We Are The World."
• The music video takes a cue from Olivia Newton-John's "Physical" video, but it's set in the bedroom, where Ross dreams of various muscle men. The campy clip didn't cross over to MTV, which wasn't playing many Black artists at the time.
• "Muscles" was the first single from Silk Electric, the second album Diana Ross released under her new contract with RCA. She was previously with Motown, starting in 1961 when The Supremes signed to the label, and then in 1970 when she went solo. Ross ended up returning to Motown in 1988.
• Gil Birmingham, who plays Thomas Rainwater on the TV series Yellowstone, is one of the muscle men in the video, which was his first acting role.
• The rapper Jeezy sampled this song on his 2006 track "The Inspiration (Follow Me)."