Matt Cancellare stands in front of you holding up a pair of padded boxing mitts. “Come on, give me more. I know you got it,” he says.

You throw combinations of punches until your shoulders ache and you can barely raise your gloves. You feel like giving up, yet something in his voice compels you to dig a little deeper and keep punching until the round is over. An alarm chimes.

“Time,” he calls. “Relax.”

You let your arms drop to your sides and walk in circles, breathing deeply to regain your wind. When he calls “next round” you raise your gloves once more for three minutes of hitting. You take a deep breath, shake your head to get focused, and resume.

From the streets of San Juan, Puerto Rico to the gyms of New York city, Mr. Cancellare has honed his skills as a boxer and trainer. Now, he’s bringing his love of the sport to Martha’s Vineyard and sharing its virtues as a dynamic physical exercise. Mr. Cancellare works with clients in his private gym, a converted garage lined with boxing posters, trophies, gym equipment, gloves, wrist wraps, punching bags, and other paraphernalia of the sport. A pair of battered red boxing gloves hang on the wall with the word “Cobra” written on the front, a memento from Mr. Cancellare’s career as Matt (Cobra) Cancellare on the New York boxing circuit.

He is quick to dispel the myth that if you take boxing lessons you’re going to hit and get hit. He has clients ranging from ages 9 to 70, and while some come to prepare for sparring, most are there for a fitness workout.

“The majority of my clients are female who hear about boxing from other females and say, ‘I’d love to try it but I’m scared of it. When they come in they see there’s nothing to be frightened of, we’re not hitting anybody and nobody is hitting you. Boxing works every muscle in your body. You never have to actually hit somebody and nobody has to hit you back to get the benefits of a great cardio workout, strength training, and muscle confusion (where you mix exercises to keep muscles from reaching a plateau).”

Mr. Cancellare, 30, was born in Baltimore, Md. and moved to San Juan, Puerto Rico where his father was stationed in the Coast Guard. When he was 12, Eddie Santos, a retired Coast Guard officer, brought Mr. Cancellare to a local gym and introduced him to boxing. The trainers saw potential in the young athlete and began instructing him in the fundamentals of the sport. In 10th grade he moved to Staten Island and began training at Rivera Boxing in Brooklyn with owner Angel Rivera. Mr. Cancellare also frequented Gleason’s Gym, the legendary boxing establishment where Muhammad Ali, Joe Frazier, Mike Tyson, Arturo Gatti, and other luminaries of the sport have trained.

“I learned a lot from Angel and the other fighters, a lot of world champions,” he says. “It rubbed off on me. If you want to pursue boxing you have to train hard and continue working hard every day. You can’t take days off, slack off and eat junk food.”

Mr. Cancellare credits boxing with keeping him focused and avoiding many of the pitfalls that can tempt a youth in San Juan and New York city or anywhere else, for that matter.

“It kept me constantly having to do something productive, whether it was training, running, boxing, or watching other boxers. I’m very thankful I had that because it kept me focused on a positive outlet opposed to other things teenagers get themselves into.”

After participating in the New York tournament circuit, Mr. Cancellare spent two years as a professional Golden Gloves competitor. When he moved to Fayetteville, North Carolina, he switched to his other passion, football, playing several seasons with the Fayetteville Guard arena team as a wide receiver. Upon moving to Pensacola, Florida with his wife, Nicole, he joined the semipro Panhandle Crusaders team. When his wife made a career shift from banking to the Coast Guard, she informed Mr. Cancellare that she’d been assigned to Station Menemsha. In 2010 they moved with their three sons, Andre, Anthony and TJ, to Martha’s Vineyard.

“I didn’t know much about the Island, but I went into it with a “support my wife” attitude, and I ended up in paradise, the best place on earth,” he says. “No matter where we go after this, it won’t be the same. We’ll always miss Martha’s Vineyard and want to come back. The station term is three years, but we’d love to stay a lifetime. They’ll have to kick us out.”

Mr. Cancellare, a certified personal trainer, applied at the YMCA to join the training staff. It turned out to be a natural fit.

“I’ve met a lot of good people through the Y, good friendly folks, which is what the Vineyard has to offer. I think I’d be lost without it. It’s a great place to go.”

As word of Mr. Cancellare’s background spread among the Y clientele, people began approaching him about boxing lessons. He saw it as an excellent opportunity to dispel the misconceptions about the sport.

“People think of boxing as a brutal sport, but it really is a sweet science,” he says. “It’s a hit-and-not-be-hit sport. I’m not hitting you because I hate you or dislike you. I’m hitting you because it’s the rules of the game. That’s what we do, just like in football we tackle each other, but it doesn’t mean we hate each other.”

Mr. Cancellare has an uncanny ability to read the energy and motivation level of clients, pushing them further than they would go on their own without overtaxing them.

“I love to give positive reinforcement,” he says. “You find whatever the client did right, focus on that, and then teach them what they can do better.”

Between sessions, Mr. Cancellare’s sons enter the garage with questions about homework. One carries a book and points to a word, asking what it means.

“Soar,” Mr. Cancellare says. “It means to fly high above. Like a kite.”

Mr. Cancellare sends them back, saying “When I’m done, I want to see that homework to make sure it’s done right.”

He says he strives daily to teach his sons the work ethic that has guided his athletic career.

“I want my sons to be productive when they get older. Whatever it is they choose to do, I want them to find something that makes them happy and then put their whole effort into it, to never quit or give up. A lot of time when I’m helping the high school football team with strength conditioning I bring them with me so they can see how I work, what my motivation is, how you don’t show up late or cancel if its raining.”

Mr. Cancellare believes his sons benefit from witnessing their mother’s dedication to the US Coast Guard. Mrs. Cancellare is currently an E4 Seaman with aspirations to progress to officer rank as an intelligence specialist.

“They get to see her commitment to the Coast Guard and the country, the sacrifices she makes, the different training she does. I think that will play a role in their work ethic over time. It still blows my mind every day to see her strength, where she came from, where she is today, and where she will be 5, 10, 20 years down the line. One of the many things I love about her is that if she says she’s going to do something, she’s on top of it until it comes to be true.”

Mr. Cancellare says the patience he’s cultivated raising three young boys has helped inform his training.

“You need patience and understanding in training. A lot of people say ‘I can’t do this’ and you have to motivate them to believe in themselves. I believe in them, I know they can do it, so the trick is to put that back into them and watch them say, ‘Wow, I can.’ Part of what I do as both a father and a trainer is teaching, ‘Yes, you can do it, this is not that hard. If you practice it will become easy.’ We’re not born walking. We learn to walk, we’re taught to walk. It’s the same thing with anything else we do in life.”

Mr. Cancellare takes pride in the knowledge that his training is making a positive difference in clients’ lives.

“Sometimes when clients come into the session they might be a little bit down, might have some things on their mind. They might share it with me or they might not, but I can sense that they have something inside. So we get to work, hitting the mitts, and soon they feel the endorphins kicking in, they’re starting to sweat. All of a sudden they’re smiling, feeling positive again, and they’re saying, ‘Matt, this is just what I needed. I needed to be pushed, to be sweated, to be stimulated this way.’”

Even though training itself is physically and mentally demanding, Mr. Cancellare says the work is a joy rather than a chore.

“The energy that I put out, my clients give me right back, so I’m never out of energy. I love it. I wake up in the morning and get excited when I realize how many clients I get to see today, people who will be happy to see me and who I’m happy to see. It’s a blessing to be able to affect people that way.”