On an overcast morning in late August, more than 30 girls entering grades 1-8 gather behind Edison Intermediate School in Westfield, New Jersey, drilling for a new sports camp. 

Coaches lead the girls in a series of warmup exercises. They learn how to hold, throw, and catch the brightly colored footballs. Some of the participants giggle as they skip and side-shuffle. The girls do a relay race before taking a short break. 

The girls are practicing for a new summer camp: Blue Devil flag football. A modified version of American football, flag football has been gaining popularity not just in Westfield, but across the country.

In addition to being safer than tackle football, flag is also more accessible to a wider group of people. You don’t need to be huge to play it (agility, speed, and strategy are more important than size and strength), and you don’t need a lot of expensive equipment. 

“In the last 10 years, it’s boomed,” says Russ Crawford, author of “Women’s American Football: Breaking Barriers On and Off the Gridiron.” “Football is the most popular sport in America, and the girls want to play.”

On an overcast morning in late August, more than 30 girls entering grades 1-8 gather behind Edison Intermediate School in Westfield, New Jersey. The fields are home to a new summer camp: Blue Devil flag football.

Coaches Matthew Andzel and Sara Liptack, along with two female high school students, lead the players in a series of warmup exercises. Some of the participants giggle as they skip and side-shuffle. Afterward, Mr. Andzel shows the girls how to hold, throw, and catch the brightly colored footballs. The girls do a relay race before taking a short break. Then the coaches do some drills, instructing players to catch the ball and keep running.

Ms. Liptack’s 9-year-old daughter, Lyra, is among the participants in the camp. “I like how there are so many girls here, and some are so good,” Lyra says. “The older ones help the little ones. It’s fantastic.”

A modified version of American football, flag football has been gaining popularity not just in Westfield, but across the country. Since 2015, participation by 6-to-12-year-olds has increased 38%, according to NFL Flag. Tackle football among that age group has dropped by 29%.

“In the last 10 years, it’s boomed,” says Russ Crawford, author of “Women’s American Football: Breaking Barriers On and Off the Gridiron.” “Football is the most popular sport in America, and the girls want to play.”

In the United States, traditional tackle football is available to girls, with teams such as Utah Girls Football in Salt Lake. Girls also play the contact version of the sport on boys’ teams. “With the growth of the concussion crisis, flag is a more socially and medically [secure] way for girls to play,” explains Dr. Crawford, a professor of history at Ohio Northern University.

Typically played with teams of five to eight players, flag football involves advancing the ball down the field by either passing or running. The sport reduces physical contact by replacing tackling with the pulling of flags worn by the players.