CONCORD, N.H. — Two New Hampshire cities and a town in Vermont will try to get in shape together as part of a research project to test a group-based approach to improving cardiovascular health.

Dartmouth’s Prevention Research Center is overseeing the nine-month project at Keene and Manchester in New Hampshire and St. Johnsbury in Vermont.

It is based on a program developed in southwestern New Hampshire called InSHAPE that pairs people with serious mental illness with physical fitness coaches. The new project, called InSHAPE Together, will draw from the general population.

“What’s really nice about this approach, which is in line with what we know about how people learn and change behavior, is that they’re learning together about how to make change,” said the project’s lead investigator, Karen Schifferdecker of the Dartmouth Institute for Health Policy and Practice.

Each community will enroll 30 people. Participants ranging in age from 12 to older adults will attend monthly meetings on nutrition and exercise. They will set personal goals, and researchers will track how small changes in behavior affect their health.

Hoping to build on existing social connections among participants, Keene selected its group from the congregation of the Monadnock Convenant Church, where the monthly meetings will be held. The first was being held Sunday.

“The fact that they’re already linked in some way socially and through other relationships will really help us have an advantage in improving their own health, their team’s health and their wider community,” said Dr. Rudy Fedrizzi of Cheshire Medical Center and Dartmouth-Hitchcock Keene.

Jaime Hoebeke, Manchester’s senior public health specialist, said she hopes the project not only helps people improve their health but strengthens social connections among neighbors, which could boost their problem-solving ability as a group that can be applied to other issues.

“They’ll be hearing about ways to move from problem identification to action, and we’re hoping this is a way to engage community residents in the process of creating healthy environments that are great places to live,” she said.

Dartmouth has secured a variety of funding sources, including federal money, for the project. The program is free to participants.