Betsy Bell Baliunas was always intimidated to walk into the Box. The name didn’t help either. The Box didn’t look like your normal gym, Ms. Baliunas recalled. “Where are the machines? There are no machines. There’s a rope — what am I going to do with that?” she wondered. “I went . . . and for some reason I kept going back.”

That was a year and a half ago when Ms. Baliunas first joined Crossfit, the fitness regimen based on high intensity and varied functional movements. On Tuesday, Ms. Baliunas completed a total of 45 pullups and 90 wallballs (throwing a weighted medicine ball against a wall) in ladder-like increments in 10 minutes flat.

The calluses on her hands had ripped, but she paid them no mind. She taped her hands up, then hopped on the rowing machine while a group of fellow Crossfitters cheered her on.

Ms. Baliunas is one of 50 members of Crossfit Martha’s Vineyard, an affiliate of the international workout movement. Calluses are a badge of honor among Crossfitters where the intense workouts can leave one weak in the knees or unable to extend one’s arms. Participants speak in a language of wallballs and Boxes (the term used for Crossfit gyms), but it’s a community of encouragement.

“You walk in tired and walk out accomplished, that’s what I like about it,” said Ms. Baliunas, a mother of two. “Someone next to you could be lifting 15 pounds or 155 pounds . . . but there’s a camaraderie in suffering together. There’s something comforting in that.”

Crossfit Martha’s Vineyard was founded by Island native Keidy Toomey in January 2012, working out of an adjacent gym space at the Martha’s Vineyard Boys’ and Girls’ Club in Edgartown. Ms. Toomey moved to Rhode Island in September to pursue Crossfit competitions.

Enter Sara Hill Mass, an internationally ranked Crossfitter from Albany, N.Y., and now the new owner of Crossfit Martha’s Vineyard. She recently moved the organization to a larger space at the former Rickard’s Bakery on Cook Road in Vineyard Haven. From moms to cops, Crossfit attracts a host of members and is growing by the day.

Movements include box jumps, squats, kettlebell swings, barbell work and varied cardio activities. Some workouts are timed, others incorporate as many reps as possible. All workouts are universally scaleable to meet one’s strength level. Judgment is left at the door.

“Functional movements are things we’d have to do every day,” Ms. Mass explained. “We have to pull ourselves up from something, swing something over our shoulders, push something up on top of a shelf, or with dead lifts, pick something up off the ground.

“And squats, everyone has to sit down,” she added “We’re always trying to mimic functional movements.”

Crossfit began as a workout regimen for military special forces. The varied workouts prepared the troops for the unknown.

“You’d have the workout listed on a white board and you’d just have to do it, you didn’t know what it would be,” Ms. Mass said.

But in the Box, all levels are welcome.

“You have a bunch of cheerleaders waiting to cheer you on,” she said. “It carries you through the workout. You have to remember that everybody started where you started, scared to walk into a Crossfit. I started that way.”

Ms. Mass was an athlete throughout high school and played college soccer. But a twice-torn ACL sidelined her career. Determined to get stronger, Ms. Mass turned to Crossfit. Her brother had opened a Crossfit gym in Virginia and had been encouraging her to try it out.

“I finally got a friend to join with me and hold my hand,” Ms. Mass said. “We went into our local gym and I fell in love right away. Of course it was very challenging, but it was the kind of challenge I needed.”

Ms. Mass was certified as a coach in 2010. She’s also certified in kettle bell training, endurance, Olympic weight lifting, gymnastics and goal setting, which targets the mental part of your physical game.

More than four years later, her knee is stronger than ever and she’s in the best shape of her life.

“I just got the bug, you fall in love with the community, you create an amazing community and you can do so much with it,” Ms. Mass said. “I love it because when I’m done with a workout I think to myself, whatever else happens in this world, in this life, in this day, I can handle it because I just did that.”

Ms. Mass grew up in upstate New York and previously worked at Crossfit gyms in the Albany area. Owning her own gym was always a plan, and she’s worked her way through the ranks to get to this point. Ms. Mass ranked as the 12th fittest woman this year at the Crossfit Games Northeast Regionals and ranked 6th fittest in the world among 35 year olds who participated in the 2013 Crossfit Open.

Some Crossfitters come in for the workouts, others are more competitive, Ms. Mass said, but there’s something for everyone.

“The feeling of looking at something you didn’t think you could do and then doing it is so contagious,” she said. “Some of the vibe out there is so competitive I think that they forget it’s community-based. People come in, they’re stretching out, chatting about their day, they know personal struggles each other is going through sometimes, and they know this is the spot where you’re going to clear your mind. It's great.”

Myths swirl about Crossfit and its health benefits and risks. But listening to your body and listening to your coach are key.

“There’s nothing bad about getting healthy and strong and working out. We were meant to be powerful beings,” she said. “We were meant to move things and move through the world in an athletic and graceful way. Crossfit is teaching you how to use your body in a strong way.”

Sean Slavin has been doing Crossfit since February 2012. A Chilmark police detective, Mr. Slavin is a member of the SWAT team on the Island and pullups proved to be a challenge for the physical fitness test.

“I wasn’t great at those,” he said. “I just turned 40 in March and I’m definitely in the best shape of my life. I went from doing two pullups to doing 18.”

“When I leave there I feel super strong and it makes you realize you could do anything.”

Mr. Slavin’s wife, Dardy Slavin, also Crossfits.

“She’s had the same type of results, she’s super strong and probably progressed more than I have,” he said.

For Jason Neago, a member of the military, science teacher at the high school and a Crossfit Martha’s Vineyard coach, “the biggest thing is community.”

“I had been doing a lot of weight training my entire life and never found anything that had a community aspect to it,” Mr. Neago said. “It’s a new workout every day, and then having that community vibe where you could go to the gym and hang out afterwards becomes more of a social event than a feeling that I was going to the gym to work out. It gave me a chance to be competitive with a close-knit group of friends.”

On Saturday, Oct. 5, Crossfit Martha’s Vineyard is hosting a day-long obstacle run to raise money for Island Children’s School. The course includes a four-mile run with 10 stations through the state forest. Stations include pushups, situps and squats, and will be scaled to meet all fitness levels. The community event will have heat times throughout the day. For more information and to register for the event, visit Crossfit Martha’s Vineyard class schedules can be found at