Just as the December sun peeked over the horizon and broke through the clouds, a dozen men and women were hard at work at the Duxbury Bay Maritime School, racing to beat themselves in a true test of “mind over matter.”

These highly ambitious people are students of Mary Fran Grossman, a beloved rowing coach and self-proclaimed “erging cheerleader.” “Erging” refers to the use of an ergometer, an indoor rowing machine that records the progress of the user through the amount of energy he or she is using during a workout.

Grossman teaches six-week adult indoor rowing classes on Tuesday and Thursday mornings starting at 6:30 a.m. With a combination of rowing sprints, core training and technique, Grossman’s classes focus on fitness through rowing.

In the last class of the year on Thursday, Dec. 20, the adult students raced against previously recorded times to see how far they had progressed in the six weeks. Many of these dedicated rowers have been students at DBMS for many years and look forward to returning in 2013.

Grossman said she views the classes as a great way to stay in shape over the winter months and she enjoys getting people together to help them stay active.

“We’ve developed a community here,” she said. “We accept anyone, even if they have no experience. It’s great to watch the growth of our students from start to finish.”

Jeanine Boyle, a long time rower and student of Grossman’s, said she became interested in rowing after seeing the boats out on the bay from her office window. For six years, Boyle has been training and competing through DBMS.

“I started rowing six years ago and I just haven’t stopped,” Boyle said. “I love it.”

Boyle said her favorite part of rowing is being out on the water and getting to see Duxbury from a new perspective.

“It’s a very special way to appreciate where you are,” she said. “It’s a beautiful way to start your day, especially in Duxbury.”

Boyle competes with Laura Carlton and Liz Connors in rowing races and the three women train together at the indoor classes on Tuesday and Thursday mornings with Grossman.

Carlton said the indoor program is a great way to stay in shape in the off-season, when rowers can’t take advantage of the open waters in the bay. She said getting up early to train improves her day.

For some rowers, the hardest part of the workout is actually getting out of bed in the morning. Annie Potash said compared to the five minutes before she has to get out of bed, the workouts don’t seem too bad. Potash’s son rowed in high school and she said she decided to try it out for herself.

“All the students just love Mary Fran,” she said. “Its a great way to get in shape and to meet people.”

Duxbury High School rowing coach Kristen McCarthy said the indoor rowing room has proved crucial to the success of both adult and student rowers. Frequently, former DHS rowers return to work out on the machines.

“Having this room is such a blessing,” she said. “We truly lucked out in having such a large room to have these classes in.”

Indoor rowing classes will begin again on Jan. 7 and will continue through until March, when the rowers can get back out on the water. Looking forward in 2013, McCarthy said she hopes to set up a year-round indoor rowing program for those who prefer not to be out on the water.