For the first time in three months, the Halas Hall weight room was teeming with players Monday as the Bears kicked off their voluntary offseason program.

"It feels good to be back," said running back Jeremy Langford. "When you get done with the season last year, how the season ended, you kind of want to jump back into it fast. But you take your time off and you feel good to be back."

With the offense and defense split into two groups Monday, Bears players worked on strength and conditioning in the weight room and met with coaches in classrooms.

"It was a great first day," said linebacker Danny Trevathan, who signed with the Bears on the first day of free agency after spending his first four NFL seasons with the Broncos. "We got out here and we got to work. We had fun, but at the same time I feel like we got some work done."

Given the numerous former Broncos players and coaches now with the Bears, Trevathan felt very comfortable on his first day working out with his new teammates.

"It doesn't really feel like a new team to me," Trevathan said. "I feel like I'm home. Some of these guys I already knew, and everybody has the right attitude and the same mindset. We're just putting in that work right now, and that's what it's about. The offseason right now is all about putting in that work for the season."

Bears players are confident that they will be able to improve upon last season's 6-10 record in coach John Fox's first year as head coach.

"We're all positive," Langford said. "We think we're going to be a really good team. We had a couple games we lost close, and I think it's going to change this year. We're just all positive and think we're going to be a real good team this year."

Trevathan, who won the Super Bowl last season with the Broncos, likes the mentality he saw from his new teammates Monday at Halas Hall.

"I feel like they're hungry," Trevathan said. "They didn't come off a winning season. They're hungry for more. These guys have the right attitude and the right hustle and I just like the vibe that's going around. I like the attitude and I like where we're at right now. There's some work to be put in, but we're definitely going to get it done."

The Bears' offseason program will continue through the middle of June. In accordance with the NFL's collective bargaining agreement, offseason programs are limited to nine weeks and consist of three phases.

During the first two weeks (Phase 1), activities are limited to strength and conditioning and physical rehab, with only strength and conditioning coaches allowed on the field with players. Helmets are prohibited, and footballs are permitted on the field only for quarterbacks throwing to receivers provided they are not covered by other players.

Over the next three weeks (Phase 2), all coaches are allowed on the field. Workouts may include individual player instruction and drills, but helmets and drills pitting the offense against the defense are prohibited.

The final four weeks (Phase 3) may include up to 10 days of organized team activity (OTA) workouts. All coaches are permitted on the field and players may wear helmets, but one-on-one drills involving the offense and defense are not allowed.