Jane Fonda appears on NBC News' "Today" show Today

Jane Fonda appears on NBC News' "Today" show Today (Peter Kramer, NBC/NBCU Photo Bank via Getty Images / April 18, 2012)

Decades after revolutionizing the fitness world, Jane Fonda and Richard Simmons are back doing what they started: starring in exercise DVDs and teaching workout classes.

Fonda is 76 and Simmons is 64, and neither entrepreneur seems ready to slow down. Fonda, the actress who brought fitness into the home and to the masses with her famous 1982 video "Workout: Starring Jane Fonda," has launched a series of new fitness DVDs targeting baby boomers. Her latest book, "Prime Time," is a guide on living and aging well.

Simmons, still sporting his tight Dolfin brand shorts, can be found teaching his signature aerobics class twice a week at Slimmons, the Beverly Hills, Calif., exercise studio he founded in 1974. The self-appointed "clown prince" of fitness also travels around the country teaching hundreds of classes a year at schools and conferences.

Both Fonda and Simmons have had eating disorders; both used exercise to cope. They've both made up-tempo aerobics accessible to underserved groups. And the two fitness pioneers both plan to keep moving as long as possible.

Today, the living legends email one another on a regular basis and speak fondly of each other. They recently talked about everything from how the fitness landscape is changing to how they cope with aging bodies.

Richard Simmons

Q: Hello, Richard?

A: (Simmons opens the phone interview with a song. It's 7 a.m.) Already, I've talked to 20 people. I start phone calls at 4 a.m. to cheer people up. The housebound, people in the hospital. People who, after decades, still can't get over what happened 10 or 15 years ago.

Q: What's different about people today?

A: Truthfully, everyone knows how to eat right. They know the difference between oatmeal and a jelly cream doughnut. They know how to walk. Everyone has this in their brain. When I started, we didn't have all this knowledge. Forty years ago, I lost my weight, but only by watching what I was eating.

Q: What would you tell your 16-year-old self?

A: Stop trying to find something in food that will make you feel better. I used to have eating disorders; I'd binge and purge all the time: fried oysters, po' boys, muffulettas, beignets, coffee and doughnuts. I tried to medicate myself with food when people made fun of me or hit me with a bat in school. I'd always turn to food. Knowing what I now know, I'd turn to me.

Q: What was your workout today?

A: Today I'll do 45 minutes of chest and back exercises at the gym in my house. When I go to teach, that's not my workout. It's my show. I'm 134 pounds — I'm a teeny thing. I work out 11/2 hours a day and eat 1,600 calories. I can't stray because I have to fit into these Dolfin shorts! They don't make the material anymore. It's flammable. So people send me their old pairs. I have 300 and wash them by hand.

Q: Wow. Are you wearing them now?

A: I actually am in all-white pants from H&M, a white zip-up hoodie and a white Gap tank top. In class, I wear outrageous and crazy outfits. Slimmons is my theater, and I get to be whoever I want. Tonight I'm going as an Egyptian pharaoh. My job is to spin a web around all these people so they don't know they're working out. They aren't going to think of their MasterCard bill, their relationships. They will just come in, have fun with me and leave in a better place.

Q: How do you connect with younger people?

A: I'm 64, but I act like I'm still 12. I go to schools. At colleges, they come out in droves, they almost scare me. I think it's just to see if I'm still alive. After I work them out — and it's not easy — I sit them down and we have a serious talk. Are they eating? Working on their body? I can say things parents won't say. No matter where I go, I talk to each one individually after I teach. They tell me things like, 'I'm starving, guys like girls thinner.' I give them concrete advice about self-image and self-worth.

Q: What's the biggest mistake today's fitness trainers make?