SANTA CLARA, Calif. (AP) Alex Boone strolled through Levi's Stadium in a tank top with his large, tattooed arms on full display.
''You don't see very many fat guys walking around here anymore,'' he quipped. ''That's for a reason.''
High-intensity, fast-paced practices early in training camp certainly help that cause.
The 49ers left guard and his offensive linemates are taking their fitness more seriously in order to do their jobs more effectively from Day 1, fully aware they are considered one of the biggest question marks surrounding San Francisco's roster going into the season.
Right tackle Anthony Davis announced his surprising retirement at age 25 two months ago following a concussion last year, and left guard Mike Iupati departed for the division rival Arizona Cardinals as a free agent. Those losses were a huge hit to a line that had been a model of stability in recent seasons. Davis and Iupati were both first-round picks in the 2010 draft and became immediate NFL starters.
San Francisco's offensive line is out to prove something after a disappointing year in which quarterback Colin Kaepernick took 52 sacks, second most in the league behind the 55 on Jacksonville's Blake Bortles, and the offense struggled with regular clock problems.
So far in camp, the defensive front has appeared dominant.
''No, I do not have any concern right now,'' coach Jim Tomsula said Tuesday of the O-line. ''Are there things we're looking at? Yeah. Am I excited about the guys in the mix, with our inside two there, yeah, I'm excited about them.''
In the first padded practice, new cornerback Shareece Wright made a nifty interception against Kaepernick and ran it back about 30 yards for a pick-6. Former Australian rugby league star Jarryd Hayne saw time with the first-team offense and made a 15-yard reception on a Kaepernick pass.
Boone was hoping for a little contact with new defensive tackle Darnell Dockett given their ''old-time rivalry'' during Dockett's time with the Cardinals, but they're on different sides of the line.
Boone has moved from right guard to left guard, where he now works alongside veteran left tackle Joe Staley. These two will be counted on for their experience and leadership on a new-look line.
''It's different,'' Boone said. ''I think the one thing people forget is that when you play next to somebody, especially in such tight quarters like we do, you have to know that person really well. You have to know what they're thinking at all times. There has been some miscommunication and things like that, but at the end of the day we're cleaning it up. It's just part of the process. We've got to keep playing together. ... It's coming along pretty well.''
San Francisco was forced to use timeouts with the clock winding down last season. The Niners were penalized at times, too, for failing to get a play called in time.
''It took a long time last year to get plays off. That was a problem, and I think everybody knew that was a problem,'' Boone said. ''It pissed a lot of people off including the offensive line, so for this offense to get rolling, get moving, it's completely different but at the same time I love it. You're just going, you're not thinking, you're just moving and you're doing what you're supposed to do.
''We just know that we've got to break the huddle a lot faster if we want to win some games.''
Joe Looney, slated at center with Daniel Kilgore recovering from another ankle surgery, has impressed Tomsula with his conditioning and is in the ''best shape of his life.'' Second-year pro Marcus Martin has been lining up at right guard, while Erik Pears has been getting the most repetitions at right tackle.
''We're out here to play football,'' Boone said, ''We're not out here to do anything else.''
NOTES: LB NaVorro Bowman had a rest day but is scheduled to be a full participant in padded practices. ''Bow will be full go. I am going to reserve the right to be able to limit, monitor, change up with Bow, with those guys,'' Tomsula said. ... OL Ben Gottschalk was undergoing a foot procedure at Stanford on Tuesday, Tomsula said, while WRs Isaac Blakeney and Bruce Ellington both have muscle strains. ... Veteran RB Reggie Bush will be treated along the lines of retired DL Justin Smith, who regularly had days off to keep him fresh for game day. Bush and RB Kendall Hunter didn't do 11-on-11 drills. ... On the troublesome grass in Levi's, Tomsula said, ''I have no concerns at all that we will be ready to play football on a game field.'' The first home preseason game is Aug. 23 against the Cowboys. ... WR Jerome Simpson was absent for personal reasons.
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