Slight streaks of gray peek through Glenna Krebs' auburn hair. And she wobbles slightly as she paces through the Bel Air Middle School gym. In her left hand, she effortlessly spins a baton as she scrutinizes the seven girls performing a new routine.
Through her thick, gold-colored glasses, the teacher looks displeased.
"If you drop the baton, you have to practice 10 times," barks the 72-year-old.
For almost half a century, Krebs has taught generations of baton twirlers how to toss, strut and roll.
At the Harford County Parks and Recreation baton classes, Krebs expects nothing but crisp motions from her 68 students during the four-hour practice. Showing her relentless and competitive energy, she claps and counts beats and yells instructions.
"She sets high expectations," said Rachel Occhion, a 14-year-old baton-twirling student. "The way she teaches is very different."
Although Krebs can be seen pacing and shouting instructions, she is not always stern and demanding. Ms. Glenna - as her students call her - makes practice fun by holding spinning competitions and pizza parties after a long session. When one of her beginners finally catches the baton, she lets out an enthusiastic yelp and hugs her.
But three weeks into a new class, batons are still flying in different directions, bouncing off the ground, and the girls scamper to catch them.
Krebs sighs as she watches, but presses on. Pushing play on her tape cassette, the music - Connie Francis' 1962 hit "Vacation" - begins.
Once the music starts blaring (V-A-C-A-T-I-O-N in the summer sun!), she starts instructing her students.
"Wiggle! Wiggle! Wiggle!" she shouts as the routine begins.
The girls bobble their heads, spinning their batons with stage smiles stretched on their faces.
"Move your head!" she yells.
After tearing a rotator cuff, Krebs no longer hurls the stick in the air like she once did. She's slowly regaining her dexterity after surgery in May.
"My age affects what I can do with the baton," she said. "I can twirl and do finger work. ... I don't try splits anymore or a lot of the spins."
But so far, twirling has helped her health. When Krebs went to a hospital earlier this year, the doctor glanced at her charts and thought her birthday was a typing error.
"He actually said to me, `You can't be that old,'" the Manchester resident said. "Later he was telling me, `Whatever you're doing, keep on doing it. It's keeping you healthy.'"
Krebs took up twirling in 1944, well before its high point.
Baton twirling enjoyed its peak in the 1950s and '60s because it was one of the few sports open to girls, said Sandi Wiemers, the president of the U.S. Twirling Association. But its popularity dwindled after Title IX came along and opened up more sports to girls. "All at once, girls had so many choices of things they could participate in. Our numbers began going down significantly," Wiemers said.
Krebs picked up her first baton when a girl in her Hampden neighborhood started giving lessons for 50 cents.
"I just took to it," she said. "I liked to dance, but the baton - I can't explain it."
Krebs performed with her middle school and high school bands and drum corps. After she got married when she was 18, she put down the baton for a while, until she saw twirlers performing in a Memorial Day parade.
With her interest in twirling renewed, she started a group based in Baltimore called the Toppers, and coached them to several regional and national championships. She passed on the twirling tradition to her three children and several of her granddaughters.
"People think of a baton twirler as someone you see in a parade, but the majority of baton twirlers are in competitions," Krebs said. "They're athletes."
After 25 years with the Toppers, she retired the group and went to nursing school in 1983.
The part-time nurse works two days a week at a Baltimore retirement center and teaches baton twirling 15 hours a week in Bel Air, where she has been since 1993.
"Not that I don't get frustrated and aggravated, but I just love it," Krebs said. "I love seeing it come together and how excited kids get when they win trophies and medals."
To this generation, Krebs' style might seem a bit dated ("Some of it is old-fashioned - like we'll use soundtracks from older movies like Robin Hood," Rachel said) but Krebs' technique is effective.
"She's funny with things," student Maria Kopalchick, 13, said after practice. "She tricks you into doing things you think you can't do."
When the long practice is over, the girls crowd around her, yelling, "'Bye, Ms. Glenna!"
She waves goodbye and chirps back, "Toodle-oo, girlfriend."
Krebs has no plans to retire.
"I plan to do this as long as I can, as long as my body lets me do it," she said. "It probably won't be too much longer. My body might tell me to stop."
And long after her body stops, Krebs says she still hopes to twirl her batons.
"I told my kids, `Look, I want some of my batons with me,'" she said. "So they promised me that when I die, they'll put a baton in my casket. When I go to heaven and there's life afterwards, I want to make sure I have a baton."