As they reached for the sky, balanced on one foot and gently moved from side to side, participants in a yoga class held at Coastal Vineyards Sunday stretched their muscles.

But the muscle that mattered most at this event was their hearts.

They were participating to support patients and families at Boston Children’s Hospital. The class was free, but donations to the hospital were encouraged. 

Dartmouth resident Nanci Winterhalter was among those who volunteered to lead the class. A registered yoga teacher, she teaches a range of classes, including yoga for cancer survivors and accessible yoga.

She knows firsthand the help that Boston Children’s Hospital can provide to patients and their families. Her son has a rare medical problem that required visits to the hospital when he was ages 7, 10 and 17.

Her son is well now, she said, and the experience inspired her to become involved in Yoga Reaches Out, an organization that combines yoga classes and events to help support Boston Children’s Hospital.

“I had a direct call’’ to participate, she said. 

Winterhalter has led teams that have raised thousands of dollars at the annual Yoga Reaches Out yogathon, which has been held at Gillette Stadium each year since 2010.

The founder of that event, Sarah Gardner of Wayland, participated in the Dartmouth class. An idea that came to her mind while she was driving on Route 128 years ago led to the formation of Yoga Reaches Out.

Like Winterhalter, her motivation was personal. 

Gardner’s son Will was born ten weeks premature at just three pounds. He spent seven and a half weeks at the NICU at Boston Children’s Hospital. 

He will soon celebrate his 21st birthday as a healthy young man, she said.

“When you go through something like that, you truly want to give back,’’ she said. “We are so grateful to have this hospital in our backyard.’’

Since 2010, Yoga Reaches Out has helped raise more than $3 million for sick children and families at Boston Children’s Hospital.

When Covid caused the 2021 annual yogathon to be canceled, pop-up classes were instead held at various outdoor locations throughout the state.

Winterhalter knew the owners of Coastal Vineyards, who donated their spacious lawn for the event. The spectacular views created a sense of calm even before participants unfurled their yoga mats.

Gardner beamed as she spoke to the 50 or so yogis in attendance. 

“I feel like giving a hug to every one of you,” she said.

Their support makes a difference, she said, as she looks forward to the return of the in-person yogathon in 2022.

Boston Children’s Hospital “has been there for us,’’ she said. “This is an opportunity for us to be there for them.’’