There are two reasons Lorenzo Booker practices in sweatpants: warmth and added wind resistance.

Yesterday, with his black cotton sweats blowing in the breeze, Booker, the running back the Eagles acquired from Miami in a draft-day trade, cradled the football and jogged the lonely 30 yards back to the huddle.

Seconds before, Booker had caught a short pass from second-year quarterback Kevin Kolb, turned as if on a pivot, and blistered upfield - gobbling yards like a Corvette on the highway.

Kolb calls this "getting a lot of yac," meaning yards after the catch.

During yesterday's minicamp for rookies and selected veterans at the NovaCare Complex, Eagles offensive coordinator Marty Mornhinweg, stalking the freshly cut grass in sunglasses, called this "turning it up."

He demanded it from anyone in cleats and a helmet.

"It's about finishing plays," Mornhinweg said. "If we do it in practice, we'll do it in games. It's actually practicing getting the ball vertical and getting it vertical quick. Some guys are running around their feet just a little bit, and that gives a would-be tackler an angle. If you, when you catch the football, secure it and drop-step up the field, it cuts the angle down for the defender, gets extra yards and quite possibly a broken tackle."

Mornhinweg and Kolb agreed: Few do this better than Booker, the second-year player from Florida State whom Kolb said has a "one-of-a-kind burst."

In 2007, the Dolphins drafted Booker in the third round. He played in seven games with Miami, totaling 125 yards on 28 carries and 237 yards on 28 receptions. In exchange for Booker, the Eagles gave Miami a fourth-round pick (No. 115 overall).

After those years in Florida - first in Tallahassee, then in Miami - Booker's view of heat is skewed. What most consider optimal shorts-wearing weather, Booker considers a tad chilly. So he wears sweatpants.

Booker's makeshift locker is not much more than a few plastic hangers, his helmet, two pairs of dirty cleats, and the Eagles' offensive playbook - a black binder about two inches thick. Yesterday, Booker's makeshift locker was, however, missing Booker.

After the two-hour practice, Booker ducked into the weight room for a quick lifting session. Later, he talked about how his transition to the Eagles has been the smoothest of his football career despite the offense's being the most difficult.

"I'm a perfectionist," Booker said. "I expect to go out there and when you tell me something once, I get it right."

"I just love the game," he said. "I love to play football. I'm not a guy that can go out there and jog through stuff. . . . To me, there is no halfway. Going full speed and working hard is the only thing I know how to do."

Booker said that when he catches the ball in practice and turns immediately upfield, the goal is to get his body to remember the feeling so that it becomes second nature.

"You want to always get used to finishing a play or breaking a long run because you never know in the course of a game when it's going to happen," Booker said. "Long runs come very seldom, but you want to get yourself used to it so when it does come you can take advantage.

"You also get to envision yourself doing it in a game, and it probably means a little more to me because I haven't done it in an Eagles uniform yet."

Unlike most of these young players looking to carve out a spot on the roster, Booker has regular-season NFL experience. He said that, more than anything, what last year's playing time with the Dolphins gave him was confidence that he could play at this level.

"Getting a chance in games and showing them that I can handle the pressure and play with the best and not make mistakes was probably the biggest thing that I was able to do for myself last year," Booker said. "Now my goal is to show everybody else that I can be a guy you can count on all the time, not just sometimes."

Kolb said that when he heard about the draft-day trade for Booker, he was thrilled.

"He's a huge pickup for us," Kolb said. "I was thrilled when it happened, and I'm even more thrilled now that I've been out there with him."

Kolb said his excitement comes from Booker's low-maintenance attitude: He arrives prepared, and gets his work done in a dependable, time-efficient manner.

Plus, Kolb said, just like with Eagles veteran Brian Westbrook, "you can dump the ball to [Booker], and he can get a lot of yac."

Mornhinweg said that Booker has been "even a little bit better" than what the Eagles expected.

As for the second reason Booker prefers sweatpants: He's kind of like a runner who trains at altitude or a high-jumper who wears a weight vest.

"I'm used to dragging these around," said Booker, grabbing a handful of his black sweatpants. "Then all of a sudden, come game time, I got spandex on. I'm moving then."