Madonna looks back at her epic three-decade career in our new issue, on stands now. Check out more Q&A from her candid interview below.

Visit our timeline "Celebrating Madonna: The Queen of Pop's 50 Most Iconic Moments."

Your onstage stamina is incredible. I particularly enjoyed "Get Into the Groove," which you sang while jumping rope on the Sticky & Sweet Tour. How do you stay in such good shape?
I have two different workouts. I have a show-day workout, which really just gets my body warmed up and ready, and I have off-day workouts that involve everything. The kind of training I do incorporates everything from ballet to Pilates to running relays, jumping rope, jumping on trampolines, gymnastics... using all the muscle groups I use to do the show. Keeping my cardiovascular endurance is the most important. At the beginning of the last tour I was roller-skating. Then I ended up getting off the roller skates, because I kept flying off the runway and crashing into the crash-mats.

Do you cry often onstage?
[On the Sticky & Sweet Tour] there's a moment right before I sing "You Must Love Me," which is such a sad song, when I'm not linked up to time-coded video, when I take a moment to talk to the audience. On this leg of the tour, I cried when I was making a speech about the two men who worked for the scaffolding company that were building my stage in Marseilles [who died in a collapse]. I cried when I found out Michael Jackson had died.

You and Michael were born in the same month, August of 1958. What was it like to witness a kid your age do what he did?
I was madly in love with him, totally smitten. He was mind-bogglingly talented. The songs he sang were not childlike at all.

When did you first meet him?
I met him in the early Eighties, when I first started working with my manager, Freddy DeMann, who at the time was managing Michael Jackson. I saw him play at Madison Square Garden, and I was blown away. He was flawless. There was a party at the Helmsley Palace Hotel. He was very shy, but it was a thrill for me.

Were you jealous of him?
In a good way. I'd wished I'd written "Billie Jean" and "Wanna Be Startin' Somethin'." What song didn't I love?

Ten years later there was talk of you recording together, and you went to the Oscars with him.
There was a period of time when we hung out. He wanted to work with me, I think he wanted to get to know me, and I wanted to do the same. When you write with somebody, it's a weird experience, you feel vulnerable and shy. When I worked with Justin Timberlake I felt that way. To write songs together is a very intimate experience, like getting tossed into a juggernaut. "On your mark, get set, create!" You have to get past these hurdles, which are, "I want to impress this person, but will they think my ideas are stupid? What if their ideas are stupid? Can I be honest with them? Will they be offended?" You end up talking and gabbing and socializing, and you have to do that in order to get to the next level, to be creative. So that's what we were doing: watching movies, having dinner, hanging out, going to the Oscars, being silly, seeing if we could work. He got relaxed. He took off his sunglasses, had a glass of wine, I got him to laugh.