You know what he looks like. The sparkling tank top and barely there short-shorts. That hair.

Perhaps you know he wasn’t always in the greatest shape. A New Orleans boy in love with his hometown food (and it showed), he turned himself into America’s loudest, dancingest, sweatiest, most-recognizable fitness icon.

But did you know Richard Simmons turns 60 this year? Speaks Italian? Read the pope’s color aura (gold, yellow, orange, green)? Did you know that pseudo-Afro on his head is a result of three “horribly painful” hair transplants, 4,000 follicles each time, necessitated after a crash diet at age 19 turned him bald? You may not know that he describes himself as an “extreme Catholic,” who will, in a quieter moment, pray with you. He’ll embrace you, close his eyes and tears will form. He’ll whisper in your ear that God is looking out for you from above, and that he created only one of you, so take care of yourself.

And then, he will burst into a chorus of Captain & Tennille in that inimitable tenor — “Do that to me one more time. Once is never enough!” — just to remind us that, after all, he is Richard Simmons.

But the biggest thing you don’t know about the man born Milton Teagle Simmons is that he’s in on the joke. You may see him as an exercise icon or the butt of the joke — he doesn’t care either way.

You can laugh with him or laugh at him, as long as you’re just laughing. This he wants you to know.

And so we find Simmons at WGN studios, having just led the “Morning News” crew in a group cardio-dance. In the hallways, Simmons runs into meteorologist Tom Skilling. Naturally, Simmons accosts him.

Simmons (singing): “Tommy, Tommy, Tommy, do you love me?” Skilling: “We all love you. How are you?!” Simmons: “Tommy, am I a shower, or am I a storm?” Skilling: “You are a storm. . . .” (Simmons grabs Skilling by the noggin and kisses his head four times.) Skilling: “Oh, are you something else!”

Today is one of the 200 days each year Richard Simmons is on the road, giving motivational speeches, posing for fan pictures or promoting whatever new product he has out. This time, he’s in Chicago because his “Sweatin’ to the Oldies” — the “Citizen Kane” of workout videos — turns 20 this year. (But wait, there’s more! It’s out now in a five-disc DVD boxed set!) Richard Simmons travels everywhere dressed like Richard Simmons. On this trip, Simmons has five pairs of tank tops and shorts with him, including a crystal-encrusted black top with the word “SWEAT” in ruby red (he has hundreds of different versions back home in Los Angeles).

In his carry-on bag are underwear, socks, pajamas and bedroom slippers.

“I’ve never seen him in jeans,” said his longtime manager Michael Catalano. “It’s not his style.”

When not at his appearances, Simmons does not leave his hotel room. Rarely does he do restaurants because people are always curious about what’s on Simmons’ plate.

Also, he thinks those in the same dining room as Simmons get self-conscious about eating in the company of a fitness guru — wouldn’t you feel weird asking for extra bearnaise sauce with Richard Simmons at the next table? So he prefers room service.

For breakfast this morning (he’s in bed by 9 p.m., awake around 4:30 a.m.), the Peninsula hotel staff brought Simmons cereal and fruit — always fruit.

The first word (or so he claims) that came out of baby Simmons’ mouth was a portentous one: “kitchen.” Growing up in New Orleans in the 1950s, Simmons would head to the French Quarter every day after school and sell pralines on the street corner.

By eighth grade, Simmons weighed more than 200 pounds. In his autobiography, “Still Hungry — After All These Years,” he wrote: “While other kids my age began exploring their sexuality, I spent time exploring food. Food became sex for me — it became my pleasure.” Simmons’ weight made him the target of bullies. The only way to fend them off, he found out, was through laughter.

“In high school, I could get beaten up all the time, or I could be something better. I became the court jester.”

It is why Simmons is prone to hugs, seconds after meeting you. He will grab your hand and kiss it with an audible smack of the lips. When he enters a building, he goes through the revolving door twice for comedic effect. It’s campy and over-the-top, and you don’t quite know how to react, except to think Omigod. It’s Richard Simmons.

In the mid-’70s, Simmons opened Slimmons, a health club that catered to the overweight (he still teaches classes there today). The success of his club led to fame and television stardom. He appeared as himself on the soap opera “General Hospital” and later hosted a syndicated daytime talk show.

Simmons talks while sitting cross-legged on the floor in the middle of the WGN hallway. Again, the impulsiveness — he will grab your arm and sit you down in the middle of anywhere, so you’re both on the same level.

“I do this because I’m supposed to do this. Every morning when I get up, I ask God what he wants me to do, ask him to lead me to the right people to help them.” His voice breaks. It’s the first of several times this day he’ll cry while reminiscing about his younger days, and how this has shaped his life’s mission. Mention that kids today will live a shorter life than their parents because of their eating habits, and Simmons chokes up, his ebullient voice turned into a whisper.

“All I’ve found are snake-oil salesmen who want to sell these overweight and obese people pills and shots and surgeries. I didn’t think that was ever going to happen.” Last year, his celebrity reached Capitol Hill. Simmons worked with Reps. Ron Kind, D-Wis., and Zach Wamp, R-Tenn., on a House bill giving financial incentives to schools that integrate physical education into their curriculum. Right now, the bill is in a holding pattern, and Simmons doesn’t expect anything to be signed until the next president is inaugurated.

But more than the TV appearances, the cookbooks, all his videos combined, he wants to be remembered for this.

One big thing you and I don’t know about Richard Simmons is his personal life. He rarely discusses it and, when prodded, says there is none to speak of.

“There are sacrifices you have to make. I don’t have a lot to offer one person. I have a lot to offer to a lot of people.” He says he has very few friends. He calls himself a loner. He lives in the Hollywood Hills with two maids and his Dalmatians, which he named after characters from “Gone With the Wind” (Scarlett, Pittypat, Melanie). When he’s out of town, he calls his house every night to talk with his dogs and sing to them.

His says his life companions are the fans who line up for hours to tell Simmons their life stories, who sum it up in the few seconds they have together.

The day brings him to a Walgreens in Western Springs, Ill., where he is greeted by 200 or so people.

“Hiiiiii everybody!” Simmons practically yells out. He walks past the stacks of Pringles Cheddar Cheese chips on sale, past the cashier and plops himself on top of a table.

He has had a costume change since the WGN appearance earlier — Simmons now sports a blue “Sweatin’ to the Oldies” tank, with blue-and- white striped shorts that barely cover his upper thigh.

The first person waiting for him is Joan Ochwatt, who is 72 but looks several decades younger. She credits Richard Simmons. Ochwatt has built an exercise room in her Willow Springs home, where she works out to Simmons’ tapes every day.

“I used to wear this shirt,” Ochwatt said, showing off an extra-large Richard Simmons T-shirt. “And look at me now!” She poses with the “after” exuberance of a before- and-after shot.

Just as quickly, the moment turns quiet. An obese woman approaches Simmons. Even surrounded by people, no one can hear what the two are saying to each other. You see they are staring into each other’s eyes.

Simmons whispers something, and she nods. He grabs her by the hand; they bow their heads and begin to pray together.

Long after the crowd disperses and night falls in Western Springs, Simmons wants to find a quiet place to talk.

He heads straight into the employee washroom. He plops right down on the spotless floor, cross-legged. He takes several deep breaths.

The past two hours — the people, their stories, the emotional feedback — have overwhelmed him.

Richard Simmons begins to weep again.

“I just hope I help some people, that’s all.” Minutes later, he’s back by the cosmetics aisle, singing snatches of music and posing for group shots with the Walgreens staff just as they return to their shifts. And his audience is laughing, as they always do, just as he wants.