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Group cycle classes offer low-impact intensity, camaraderie

Instructor Becky Krubsack leads a cycling class at the Center of Personal Fitness on Thursday. Steve Kuchera / skuchera@duluthnews.com1 / 6
Riders fill the bike cave Wednesday during a cycling class at the YMCA in Duluth. Clint Austin / caustin@duluthnews.com2 / 6
Jenifer Martinsen of Duluth pedals a stationary bike Wednesday during a cycling class at the YMCA in Duluth. Clint Austin / caustin@duluthnews.com3 / 6
Rope lights are the only source of light in the bike cave Wednesday during a cycling class at the YMCA in Duluth. Clint Austin / caustin@duluthnews.com4 / 6
Community Health Specialist Jenifer Martinsen of Duluth gives instructions Wednesday during a cycling class at the YMCA in Duluth. Clint Austin / caustin@duluthnews.com5 / 6
A biker’s feet and lower legs blur while cycling at the Center for Personal Fitness on Thursday. Steve Kuchera / skuchera@duluthnews.com6 / 6

Becky Krubsack pumped her shoulders to the rhythm as her feet spun under her. The Center for Personal Fitness instructor danced and pedaled as she directed a full group cycling class.

"We're going to start a scenic climb, four above flat, one minute. Then, we're going to do jumps."

Some answered in light grumbles, another asked, "Where are we going to jump from."

"The pool," Krubsack said.

Soon class members pulled a red handle on their stationary bikes. Resistance levels increased, and each stood up, pedaling faster, Krubsack among them.

Cycling classes are low-impact exercises. Classes work the heart, gluteus maximus, quadriceps, hamstrings, and you can burn 600 or more calories in an hour, according to TIME.

Miranda Aubart rehydrates while cycling at the Center for Personal Fitness on Thursday. Steve Kuchera / skuchera@duluthnews.comThere are only so many things you can do on a bike, but Krubsack tries to switch it up. She's a trail runner, so she'll imagine dips and levels of intensity on trails and chart a workout according to that.

"For the most part, you're going to get just as good of a workout inside and outside if you do it right and mimic the resistance of the air and the hills," she said.

Music and visualizations can help you get in the zone, she said. Her go-tos are in nature, and she encourages attendees to start at a certain level of resistance so they're not "chasing pedals."

Krubsack teaches kickboxing and strength training, too, and her job is instructor and part DJ, because in any group fitness class, you have to hook them.

On her playlist was A Tribe Called Quest, Weezer, Bruno Mars, "a lot of Prince." You need a beat, and you have to know your group, she said.

The bikes are customizable; you can adjust the seats and handlebar height. The pedals have clips fit for cycling shoes, which are optional. They're all calibrated differently. Krubsack said it's important to talk to your instructor to get help with the equipment and verbiage — because classes have specific terms.

"Flat" is the pace you could ride comfortably for an extended period of time, said Peter Miller of Hermantown. When Krubsack says "six above flat," you're working hard the whole time.

Jumps are pedaling while standing, and it's "aggressive," he said.

Miller was still pedaling after class was over, hitting 30 miles in 64 minutes.

The 67-year-old has had a full knee replacement, and cycling is part of his regular routine. You're working all parts of your body, he said.

"I can go all out for 30 seconds, and I will, if I know there's an end point," said Bonnie Keeling, 69.

"I love this class. I used to hate it, but I love the way that I felt afterward," she said.

Keeling works harder in the group than she would on her own, and she likes the encouragement, camaraderie and the whole-body benefits.

You can't think of anything else on the bike; it helps clear your mind, she said.

She does crisis work, and classes like this are a great stress-reliever. "Come down here and pour my guts out for 45 minutes, and then it's gone."

Krubsack said it's not her workout, it's theirs, but she's working as hard as they are from the instructor seat. Part of group fitness is about community. "If you foster that environment, people are going to want to come. They're going to want to stay, and I consider that part of my job."


From the outside, it looked like a dance party with stationary bikes. The lights were low and music blared from the inside the "bike cave" at the Duluth Y during a recent cycling class.

Cyclists were already pedaling away as Jenifer Martinsen, community health specialist at the Y, shared part of the rundown:

Four-minute increments starting at 80 percent effort and ending with two minutes of recovery.

Martinsen is lively and energetic, riding hard at the front of the room. As the workout progressed, "It should feel bad," she said, reminding riders to keep their shoulders relaxed to save their energy.

Sweat dripped off chins as fans blew air in their faces. Some attendants grimaced, some had far-off looks.

"Thirty seconds, this is the only time you'll hate me today," Martinsen said with a laugh.

After class wrapped, Trish Kroening of Duluth said she works out six days a week, running, hiking, yoga. She has been riding outdoors for 30 years and taking cycling classes for 18.

She said the benefit of classes is you're at your own speed and nobody can see what you're doing.

"If you have no resistance on, no one knows that," Kroening said, recalling cycling at a low setting after an injury. She said the dark setting is soothing and makes for less pressure. Still, if you want a challenging workout, it's there for you.

Martinsen is a competitive cyclist and triathlete. She understands how to push the threshold and build endurance, and she charts her cycling workouts to how she'd train.

She goes as hard as she can in the instructor seat, and that helps motivate her students. "They all know I'm doing to them what I would do to myself.

"They may not be able to keep up with what I'm doing, but they get to set their own pace. They're in control of how hard they're pushing," Martinsen said.

Bob Toftey, 72, of Duluth, started cycling when he couldn't run anymore due to a pulled muscle.

That was 15 years ago. Now he cycles three times a week. He said he likes that he doesn't have to think about his workout, and classes help him prepare to ride outdoors.

There's a huge relief that comes from physical exertion, and Martinsen loves seeing the self-confidence in cyclists after finishing a tough section in the workout. Cycling calls for self-discipline, and that includes knowing your limits and staying within your pace.

"My favorite thing to teach them is mental strength more than physical strength," she said.

More info

Learn more about some cycling classes in the Twin Ports:

The Y:

Center for Personal Fitness classes:

Melinda Lavine

Lavine is a features and health reporter for the Duluth News Tribune. 

(218) 723-5346