WASHINGTON -- Coaches and players reconvened at RFK Stadium this week to kick off D.C. United's 2010 preseason under new boss Curt Onalfo, and even ventured outside for a Monday morning session on the RFK Stadium auxiliary turf field, despite 20-degree temperatures and ample snowdrifts that required several hours of shoveling after a weekend storm.But for several members of the D.C. squad, preparations for the new campaign have been well underway for months thanks to injuries, international duty and the simple reality of Major League Soccer's ever-increasing physical demands.At the close of a long, grinding season, some players prefer to briefly step away from the game altogether and clear their minds during the holidays. But most profess the importance of maintaining a base level of fitness throughout the winter to make preseason's workouts less painful. That task was straightforward for Troy Perkins, Chris Pontius and Dejan Jakovic, who were called into camps arranged by their respective national teams.For those recovering from offseason surgeries, the challenge is much greater."I work harder during the offseason than I do during the season now," said midfielder Santino Quaranta earlier this winter. "For me it's a challenge of everything I eat, everything I do on a daily basis -- it makes it that much easier. It's already hard enough when you're not running and playing for a certain amount of time, and I'm injured as well, so it's like double the amount of work."Quaranta broke a bone in his left foot during practice last October, requiring surgery followed by four to six months of healing and rehabilitation. He spent late fall and winter shuttling back and forth between team-supervised work at RFK and personal training sessions near his Baltimore home, and will gradually ramp up his involvement in team activities over United's lengthy preseason calendar."I agree with Tino on that one," said defender Julius James. "Because you have to maintain your fitness and most of the time it's not with the ball, you know? So it's tougher to do all this running. You try to build up muscle mass to tide you through the season, and you have to try to get better with all this extra stuff. When we're playing, it's fun -- you're with your teammates and training is hard, but most of the time [during offseason] you're alone doing all this stuff."James earned hero status for playing -- and scoring -- in the final moments of United's 2009 finale at Kansas City despite a pulled hamstring. But the Trinidadian faced a tougher challenge in the offseason with his decision to surgically repair a long-nagging shoulder injury that first flared up back in his rookie season with Toronto FC."I feel really good, because I've had this problem since the beginning of my professional career. It happened to me in Toronto in preseason. I think we were in South Carolina and my shoulder dislocated down there," he said. "It's a lot tighter now. There was some torn stuff and the doctor said he put some nails in there to staple my stuff together. It was pretty loose, actually."James spent his holidays recuperating in D.C. before returning to the University of Connecticut, his alma mater, to labor through a painful regimen of rehab exercises to restore normal range of movement in his shoulder socket. James later joined other MLS-based alums like O'Brian White and Kevin Burns for fitness work under Huskies strength and conditioning coach Chris West.Both James and Quaranta are training this week, but will be kept out of scrimmages and other full-contact activities until mid-February as they wind down post-surgery recovery schedules -- schedules that can often feel slow and frustratingly restrictive, but usually pay off in the end."I'm really happy where I'm at. It's been a pretty long offseason," Quaranta said on Monday. "I've put a lot of work in here. It's been comforting to start running and know that they've got it right. And I know mentally they've got it right -- going out there today, cutting and being on the frozen turf, it doesn't feel great, but it's a starting point and it can only get better from there."Charles Boehm is a contributor to MLSnet.com.