But another athletic feat wasn’t necessarily the answer. Bacher, who is in her 40s and has two young children, wanted to identify a challenge that would address her interests in not only physical fitness but also the environment and sound nutritional practices for her family of four.

So she came up with an idea. Would it be possible to do all her grocery shopping by bike for the month of September?

It wouldn’t be easy; that much was certain. Bacher lives in Carlisle, which has only one small general store and no other retail establishments; the supermarkets where she and her husband, Chris Fielding, typically shop are in adjoining towns, none closer than 5 miles from their home.

“What I liked about my idea was that it was a way of feeding several birds with one crumb,” Bacher said, the pacifist twist on the usual idiom reflecting her serene personality. “This challenge addressed my goals of exercise, environmental responsibility, and healthy eating. All of those are important to me.”

But after the first week or two of grocery shopping by bike, Bacher noticed that there was another advantage that she hadn’t anticipated.

“It slowed me down,” she said. “When I drive to the supermarket, which I used to do three times a week on average, it tends to be with the radio on and my phone in my hand, a thousand things racing through my mind at once as I rush to get my errands done. Biking is causing me to be more present. I was riding down Pope Road in Acton last week seeing the trees and hearing the insects in a way I never do in a car. You just notice things more.”

“Like the hills,” chimed in her husband with a laugh.

Although Fielding did not explicitly sign on to take part in the project in the beginning, he installed a rack on Bacher’s bike and cleaned out the panniers he’d last used in college. And one September weekend he even joined Bacher for the ride to Market Basket. With two panniers and two backpacks to fill, and two riders to carry the load, Bacher said, they were able to buy almost as many groceries as they do with the car.

But grocery shopping by bike is a different experience, both agree. “I don’t zip through the store grabbing everything I think we might want. When you know you’ll be physically carrying it home, you look for nutrient density,” Bacher said. “I don’t buy chips or other kinds of junk food anymore; why let them take up the space? And I also don’t buy anything I can make myself, like pancake mix.”

Moreover, the couple found that they were making much better use of the food they did buy — as well as the food from their vegetable garden.

“Instead of deciding what I want to make for dinner and then running out to pick up this or that ingredient, I look at what we have and figure out what I can make with it,” Bacher said. “I’ve been using every vegetable that our garden has produced this summer: every eggplant, squash, garlic, tomato, arugula.”

The family also raises egg-laying chickens, so dishes made of eggs and garden produce became standard fare.

“Nothing goes to waste these days,” Fielding said in the midst of the experiment. “It used to be that if something was starting to seem a little bit old, I might throw it onto the compost pile. But now I look at it and remember that Susan or I either grew it or made the effort to carry it home over seven miles on our backs, and I decide to use it rather than throw it away.”

Now that the officially designated month is over, Bacher admits she might not maintain quite the same level of discipline, but neither has she given it up.

“I’m planning to continue making at least one of my marketing trips each week by bike, at least until it gets really cold and slippery,” she said recently.

Knowing she avoided driving all those miles — about 40 per week for the grocery shopping, and another 32 per week for the exercise class she stopped taking once she started biking so much — was satisfying, but she emphasizes that the project wasn’t strictly about reducing her carbon footprint.