Under the new contact rules, NFL teams are limited in the number of full-pad practices they can hold during the season. (Rich Schultz/Associated Press)

The days are still hot. The practices are still long and tough.

But the first set of training camps in the NFL’s post-lockout world have been a different experience for players, now that reduced-contact provisions in the sport’s new collective bargaining agreement are in effect.

“It’s different not having to go out there twice a day, which is really nice,” Baltimore Ravens cornerback Chris Carr said here last week, shortly after he stepped off the practice field. “I think we’ll really see the effects during the season. I think during the season, halfway through, we’ll see the benefits from it.”

The new rules are primarily an attempt to curb the rate and severity of concussions suffered by players by reducing the number of blows to the head players absorb over the course of a year. Offseason workouts have been restricted and hitting has been limited in practices during training camp and the regular season. The longtime training camp staple of “two-a-days,” or two full-contact practices on the same day, has been eliminated.

More broadly, the rules are intended to reduce the overall wear and tear on players’ bodies and limit injuries. But the primary goal is to help players avoid concussions and the possible long-term health consequences that many medical experts associate with them.

Ravens cornerback Domonique Foxworth said the players “made probably the biggest step in health and safety in the history of collective bargaining” by negotiating the new rules with the league.

“The hits have been reduced and the players will be safer from that,” Foxworth said last week. “As the progression goes and we learn the flaws in this system, it will be on us to correct them as we go forward. But I don’t really see any [problems] just yet.”

Under the new rules, a team can have one preseason practice per day, as long as three hours, with hitting permitted. Players wear helmets and full pads, or substitute lighter protective “shells” for full pads when a coach chooses to have a less intense practice.

Players also can be on the field for a one-hour walk-through each day, without hitting. Players must be given one day off per week.

The rules also limit each team to 14 practices in full pads during the regular season, 11 of which must come in the first 11 weeks of the 17-week season. Teams’ offseason programs have been reduced from 14 weeks to nine. The number of offseason organized team activities, or OTAs, have been reduced from 14 to 10.

Thom Mayer, medical director of the NFL Players Association, said the union’s goal was to reduce players’ exposure to practice-field blows to the head by by 20 to 25 percent.

Mayer said last week he suspects the reductions in hitting from the new rules are “going to be in that zip code,” and added: “From the medical side, we didn’t let the perfect get in the way of the very good. I think we’ve got a great program here, a solid baseline for the care of the players.”

Mayer and other medical experts said that because so much is unknown about the causes of concussions, it is impossible to make precise predictions about the new rules’ effects. NFL players reported suffering 261 concussions last season, according to a league spokesperson.

“You’re reducing the number of concussive blows and you’re also reducing the number of sub-concussive blows that lead up to the concussions, so hopefully you are reducing the severity of the concussions as well, when you do have concussions,” he said. “[But] that remains to be seen.”

There has been some pushback to the new provisions. Ray Anderson, the NFL’s executive vice president of football operations, said there was “some consternation” when NFL officials briefed general managers and other team representatives on the rules late last month.

“There was a feeling of maybe we’d gone too far and we had too many restrictions,” he said.

But coaches have subsequently reviewed the changes positively. Ravens Coach John Harbaugh said last week that he has made only minimal changes to his team’s training camp routine.

“We would never hit twice a day, anyway,” Harbaugh said. “There’s been camps where we’ve kind of gone out in the afternoon and hit early in camp, but not really that much. So I think it’s been not that much different.”

Teams now will be limited to an average of just less than one full-contact practice per week during the regular season. But many coaches already had been following that formula as they tried to keep players fresh and healthy. Carr said when he was with the Tennessee Titans in 2008, the team had just two practices in full pads all season and still had one of the league’s top defenses.

“I think a lot of the hitting sometimes is extremely unnecessary,” he said. “So I think the rule changes are great and I don’t think the games will be any less severe. If anything, guys will be out there fresher and there will be harder hits on Sundays.”

Mayer said he’s hopeful that the NFL’s elimination of two-a-day practices will lead the governing bodies regulating younger players, including high schools and youth football organizations, to follow suit. College football previously limited two-a-days.

The new provisions haven’t prevented at least 10 players from suffering Achilles’ tendon injuries in the opening weeks of training camps. Anderson said he was “a little alarmed” about that run of injuries, but both he and Mayer expressed hope that they will subside.

New York Jets linebacker Bart Scott told the Newark Star-Ledger last month that the elimination of two-a-days in training camp was “wimping out” and “making football more soft.” But Foxworth, a member of the union’s ruling executive committee, dismissed such criticism.

“Find those guys in Week 15,” Foxworth said. “Find them again and ask them how they feel about this league being soft and about us needing to hit more.”

Some players have been critical of other steps toward safety taken by the league. Some members of the Pittsburgh Steelers were sharply critical of the NFL’s stepped up enforcement of rules on illegal hits to the head of an opponent last season.

But Richard Ellenbogen, co-chairman of the NFL’s head, neck and spine medical committee, said he has found players to be overwhelmingly receptive to concussion-related changes, which previously included prohibiting a player with concussion symptoms from re-entering a game or rejoining a practice. The league requires a player who suffers a concussion to be cleared by an independent neurologist before he can participate in a practice or game.

Ellenbogen said players demonstrated a willingness to self-report concussions last season.

“It has been absolutely eye-opening to me to see what’s happened in a year, to see the culture change, and the players deserve the credit,” Ellenbogen said. “They want to know what the risks are. It’s enlightening to everyone out there who said this was a warrior culture and the players will never change. They have.”

Atlanta Falcons President Rich McKay, chairman of the NFL’s competition committee, said the reduced-hitting rules probably cannot be evaluated fairly this year, because teams lost their offseason programs to the league’s lockout.

“In the offseason, we’ve gotten to a place where everyone is comfortable. In the regular season, we’ve gotten to a place where everyone is comfortable. In training camp, that’s the one place where we want to see what the effects are,” he said.