Woodgrove Coach Jerry Gordon runs his team through the first practice of the day. (Tracy A Woodward/THE WASHINGTON POST)

Football has long been about bone-crushing hits and a rub-some-dirt-in-it mentality. But in an effort to help rid itself of that image and curb the rate and severity of concussions, the NFL this offseason eliminated the longtime tradition of two full-contact practices on the same day — a summer ritual known as two-a-days.

Though college football has put limits on two-a-days, they have remained a staple in the high school ranks. The reason, coaches say, is part necessity, part preparation and part tradition. As players across the region prepare for their upcoming seasons, tackling and hitting in two practices over one day are facts of life.

Some medical experts, however, argue that it shouldn’t be the case. Not only are developing teenagers exposed to possible heat-related illnesses across multiple hours but they are also exposed to more opportunities to bang their heads and suffer concussions.

“It’s inconceivable to me that you can take young scholar athletes at an age that is more vulnerable and have them play more dangerously than at the highest professional level,” said Robert Cantu, a co-director of Boston University’s Center for the Study of Traumatic Encephalopathy and a leading specialist in sports-related concussions.

High school coaches see two-a-days as necessary to grasp playbooks, build team unity, teach proper technique and prepare players for a season’s worth of hitting. It’s a careful balancing act with the players’ safety.

“You always worry about contact and you try to limit it,” said Jerry Gordon, the head coach at Woodgrove High in Purcellville. “But you have to be able to play football.”

Practice guidelines were generally designed with heat-related illnesses in mind, limiting when players can be in full pads. The Virginia High School League guidelines aren’t a requirement but recommend that schools adhere to a six-day acclimatization schedule. No back-to-back full-contact two-a-days are allowed until the fourth week of practice, with no one practice lasting more than three hours or totaling five hours per day. The Maryland Public Secondary School Athletic Association doesn’t set guidelines, leaving it up to each school district. In D.C., the policy allows two-a-days only after an eight-day acclimatization period, but not on consecutive days.

The surest way to combat the potential for head injury is, simply, to limit hitting in practice, where players give and receive the largest share of hits, Cantu said. He said even teenagers and young adults he has studied have shown early signs of chronic traumatic encephalopathy, a degenerative brain disease caused by head trauma, from small non-concussive hits to full-blown concussions.

When hitting is needed, Cantu said proper technique needs to be stressed and coaches should even consider using dummies to prevent full-force hits between colliding bodies. And during walk-throughs, no-contact practices where plays are rehearsed, players should be without helmets to avoid hits, he said.

By the sixth day of practice, when Virginia recommends teams first use full pads, Woodgrove’s Gordon begins full-contact two-a-days. Some days one of the practices is only in helmets and shoulder pads, which means less-intense hitting, or a walk-through.

But when it’s time for a full-contact two-a-day practice, which last two-and-a-half hours each, the hitting is on. Gordon, an old-school coach who was a lineman at the University of Massachusetts from 1978 to 1982, tries to split the hitting between stretching and teaching sessions, often split up by position, and no-contact walk-through plays “so that it’s not three hours of just hitting, hitting and hitting.”

The amount of hits his body and head take doesn’t scare Woodgrove junior Dan Charmo, a 6-foot-2, 250-pound lineman. He said he hits as hard as he can on every play unless coaches tell him not to. “It’s part of the game,” he said. “You’ve got to hit. You just have to make sure you have air in your helmet [padding].”

At Atholton High in Columbia, Coach Kyle Schmitt doesn’t hold two full-contact practices a day. In the first week of practice, the players will be in helmets and shoulder pads for the first session of the day and in full pads for the second. Even then, he generally spends 15 to 20 minutes of a practice walking through plays with the team, sometimes even without helmets.

As a former Maryland offensive lineman from 2001 to 2004 who also spent preseasons with the Minnesota Vikings and Arizona Cardinals, Schmitt understands why it’s important to limit hitting and potential injuries. A player has only so many hits in a career, he said.

“I get criticized by my own parents, concerned that we don’t hit enough,” Schmitt said, “but I’m concerned with having the kids ready for November or December.”