His résumé includes fitness videos (notably his "Sweatin' to the Oldies" series), television shows (including a stint on the American soap opera "General Hospital" in the 1970s), and his own The Richard Simmons Show in the early 1980s. He has written several books, and produced the Deal A Meal and FoodMover weight loss plans. He hosts Cruise to Lose on Carnival Cruise Lines, has made film cameo appearances, and even an exercise album in 1983.

Despite his flamboyant and comedic persona, Simmons does help seriously obese people lose weight. After losing 123 lb (56 kg), he opened an exercise studio, Slimmons, in the 1970s responding to discrimination by exercise studios of the day against the overweight. Slimmons continues to operate on Civic Center Drive in Beverly Hills, California, and Simmons teaches motivational classes and aerobics on Tuesday and Thursday evenings, and Saturday mornings.

Simmons also teaches other instructors to teach with his method, The Simmons Method. Training is periodically provided at Hoot Camp, which allows AFAA-certified instructors to earn continuing education. Held in Beverly Hills, Hoot Camp is approved by the Aerobics and Fitness Association of America (AFAA). Hoot Camp has also been held in St. Joseph, Missouri.

Popular rumor suggests that Richard Simmons is gay; however, Simmons denied this in a press release issued in September 2003.

On March 24, 2004, Simmons was arrested and charged with assault after allegedly slapping a motorcycle salesman at Sky Harbor International Airport in Phoenix, Arizona. The salesman, Chris Farney, spotted Simmons in the crowd and said, "Look, Richard Simmons! Drop your bags, let's rock to the '50s."

Simmons replied, "It's not nice to make fun of people with issues." He then lightly slapped Farney's face. Farney, who was uninjured, called the police. Revealed later was that Farney, an ex-convict, was recently released from serving three years in prison after being found guilty of aggravated assault. All charges against Simmons were dropped.

In September 2005, Simmons appeared on Entertainment Tonight to discuss the effects of Hurricane Katrina on his family in his hometown of New Orleans and his involvement in aiding those affected by the hurricane.

Simmons travels the United States, teaching classes, and spends time phoning people who ask for his help. He is active in the fitness industry and recently launched a new website. January 2006, Simmons released two new DVDs (Party Off the Pounds, and Totally Tonin'), as well as eight new CDs of exercise music. Simmons has plans to release more DVDs later in 2006.

He currently hosts a three-hour weekly radio show called Lighten Up with Richard Simmons every Sunday afternoon on Sirius radio.