PHILADELPHIA -- No Doubt's Gwen Stefani may sing of being "Just a Girl," but she's sure a strong one. In the middle of performing the band's 1995 breakthrough hit Thursday night at the First Union Spectrum, the platinum blonde executed 10 pushups.

"Where are my girls at?" Stefani asked after her workout. The distaff majority of the approximately 9,000 in attendance roared to let Stefani know exactly where they were.

Even though other female-fronted acts Garbage and the Distillers were also on the bill, it was a Gwen kind of night. The athletic and energetic Stefani, wearing a red, midriff-exposing halter top and loose black hip-hugger pants, strode, skipped and posed from one area of the stage to the other.

The band emerged in the middle of the audience in front of the stage to start its set with a taut and funky "Hella Good" from its most recent album, Rock Steady. Drummer Adrian Young remained at his multicolored drum kit in the middle of the crowd while the rest of No Doubt retreated to the stage and performed "Sunday Morning" and an explosive "Ex-Girlfriend."

The band -- including guitarist Tom Dumont, bassist Tony Kanal and multi-instrumentalists Stephen Bradley and Gabe McNair -- performed polished interpretations of ska, reggae, '80s synth rock and middle-of-the-road ballads, but it was their Technicolor pop sound that suited Stefani best. Her voice conveyed tenderness and vulnerability with personality and power, yet had enough of a growl to put teeth into the band's riot grrrl anthems.

"[Stefani's] old enough to have been through the tough times and look at them in retrospect, but not so old that the memories aren't vivid," said fan Bridget McGrath, 17, of Audubon, Pennsylvania. "She's in touch with her emotions, and she's gotten very open with her audience."

The band kept up the pace until reconvening in the middle of the audience to perform several acoustic numbers, including "In My Head" and "Magic's in the Makeup." The set gave audience members a good look at Young's outfit, or lack thereof. The drummer wore a sheer, high-cut Allen Iverson Philadelphia 76ers shirt and bull-with-unfurled-lip string thong. Young also wore pancake face powder and sloppy lipstick.

"He should at least put some pants on," said Chris Gossger, 20, of Warminster after the show.

"But it's OK for a girl to show her butt?" asked Shari Wallin, 18, of Holland.

No Doubt delivered its biggest hits after the cheeky episode, including "Hey Baby," "Don't Speak" and a show-closing "Spiderwebs."

In the context of Thursday's show, petite Garbage frontwoman Shirley Manson seemed like a smaller, yet darker, version of Stefani. Like Stefani, Manson was active and used the whole stage to sing and strut on. However, with songs about kinky activities and crossdressers and a solo roll or two on the floor of the stage, Manson added a more sexually expressive element to her band's set.

Musically, Garbage delivered a wall of industrial sound that melded itself into some very melodic pop songs. Starting with "Supervixen," the band -- featuring former Nirvana producer Butch Vig on drums, Duke Erikson on guitar and Steve Marker on bass -- performed most of its radio hits except for "Queer."

Erikson's tremolo-on-steroids sound marked "Vow," while Manson wailed like Robert Plant on "#1 Crush" and adorned herself with a pink boa for the fun "Cherry Lips (Go Baby Go!)."

"Gwen's our god, but [Manson's] a goddess herself," audience member McGrath said.

The Distillers, fronted by Brody Armstrong (wife of

Rancid's Tim Armstrong), opened the show.

"It's good to be a part of a three-pronged, all-lady venture," Manson said, and most of the young women in the crowd agreed.

"Someday we're going to have that power," audience member Wallin said.

For more sights and stories from concerts around the country, check out MTV News Tour Reports.