Dave McGillivray, race director of the Boston Marathon and the New Balance Falmouth Road Race, has run across the United States, swam from Martha’s Vineyard to Falmouth, and done the Boston Marathon blindfolded.

Most recently, at the age of 63, McGillivray completed seven marathons (26.2 miles) over seven consecutive days on seven continents as part of the World Marathon Challenge.

Among the charities he supports are the Jimmy Fund and Dana-Farber Cancer Institute; the Martin Richard Charitable Foundation in memory of the 8-year-old killed in the 2013 Boston Marathon bombings; the Joseph Middlemiss Big Heart Foundation honoring a 6-year-old who died of cardiomyopathy; and his own Dave McGillivray Sports Enterprises Children’s Fitness Foundation.

He has raised millions of dollars and motivated almost as many people by pushing the limits of physical and emotional endurance. It’s all to lend a helping hand, especially to children.

Now, as the 122nd Boston Marathon approaches on April 16, McGillivray has authored a children’s book titled “Dream Big, A True Story of Courage and Determination” ($16.95, published by Nomad Press). Written with Nancy Feehrer and illustrated by Ron Himler, “Dream Big” is based on McGillivary’s 2006 autobiography, “The Last Pick,” in which he writes of being motivated by rejection and fueled by failure.

“Dream Big” recounts the story of a small boy who wants to be a professional athlete, but is left off teams because he is too little. Still, he continues to dream big.

“I was always the last cut,” says McGillivray, who is 5-foot, 4-inches tall. “I started running because there are no tryouts and no one can cut you. You don’t have to be tall or big to be a marathoner.”

But you need to be prepared. In his first attempt at running Boston in 1972 when he was 17, McGillivray was forced to quit after 18 miles because he hadn’t trained properly. His grandfather was left waiting and wondering about him further down the course.

“I was crushed because I failed and disappointed grandpa,” McGillivray says. “But he told me something that day that has stuck with me forever. I didn’t fail. I learned that dreams don’t just come true. You have to work really hard to make them a reality. He made me a deal that if I was serious about the marathon, and trained, he would be there for me the next year.”

McGillivray says he wrote the book to inspire kids to go for their dreams. His beloved grandpa didn’t lose faith in him and that was enough to fire his passion and commitment. And the rest of the story is a laudable lesson – for kids and adults.

“You only fail if you don’t try,” McGillivray says. “You’re not always successful, but you keep working.”

McGillivray has directed the Boston Marathon for 30 years and next week will run the course for the 46th straight time. After 30,000 have finished and his duties are done, he will return to the start line in Hopkinton for a solitary race.

“I struggled when I was younger with being underestimated because I was short,” McGillivray says. “Everyone struggles with something, but my motto is set goals, not limits. We all have an obligation to help those who are less fortunate. Philanthropy gives my running a purpose instead of just being personal.”

The book ends with a challenge for young readers called the Dream Big Marathon in which McGillivray encourages kids to be fit physically, mentally and emotionally. He sets goals for them to run 26 miles, read 26 books and perform 26 acts of kindness in 26 weeks. Medals will be awarded to those who complete the “marathon.” (Details at

“I’d like kids to read the book, stay involved, have a goal and work toward something,” McGillivray says. “And when they succeed, there’s a reward for making it to the finish line.”

Copies of “Dream Big” will be given free at several elementary schools throughout Massachusetts as a gift from the Big Heart Foundation when McGillivray does presentations.

“A man never stands as tall as when he kneels to help a child.”

An internet search for that heartfelt quotation offers several sources – Abraham Lincoln, James Dodson, Knights of Pythagoras, even Anonymous – but regardless of the origin, McGillivray lives it.