Secret wind sprints, Billy?" someone asked Philadelphia Coach Billy Cunningham today after the 76ers held a two-hour workout that was closed to the media.

The coach laughed, then said it's no secret that for his team to win Game 2 of this best-of-seven championship series here Sunday it must keep pace with the Los Angeles Lakers' running game.

"They obviously are a great running team," Cunningham said after watching films of the Lakers' impressive second-half performance Thursday night. In one 10-minute stretch, they outscored the 76ers, 40-9, turning an 83-68 deficit into an insurmountable 108-92 advantage.

Jamaal Wikes led the comeback with 16 of his 24 points in the third quarter. Norm Nixon contributed 24 points and Kareem Abdul-Jabbar added 23 as the Lakers set an NBA record with nine consecutive playoff victories in one season. They swept Phoenix and San Antonio to reach the finals.

There is a dilemma facing every player who tries to defend against a team such as the Lakers that wants to fast break at every opportunity. Does he go hard to the offensive boards to try to take advantage of their players releasing too soon, or should he fall back on defense to protect against the break?

"You can't do one or the other 100 percent of the time," said Julius Erving, the 76ers' all-star forward. "You have to have a balance to keep you unpredictable so the other team won't know what you're going to do.

"We got a lot of points (14) off offensive rebounds in the first half, but then we became so conscious of getting back and trying to cut off their break that we didn't go to the boards enough in the second half and that hurt us offensively."

"What makes their break so effective is that sometimes as soon as we take a shot, Nixon and Wilkes are on the fly already, looking for an outlet pass," Erving continued. "What we've got to do is make them start their break at the base line instead of at half-court."

The Lakers' pattern all season has been to run at every opportunity. Now with Bob McAdoo blending in, the team has been almost unbeatable. Since March 9, Los Angeles has a 24-5 record. Opponents have tried a multitude of defenses, none with much success.

"What we've got to try to do is get into a counterpunching situation," Erving said. "We've got to try to force them to make mistakes when they're running. On their fast break, they usually have four men involved, so if we can create a turnover, we'll have them three on one."

Bobby Jones, a perennial member of the league's all-defensive team, says he was impressed by the relentless style of the Lakers' attack.

"They have one of the best fast breaks in the league," he said. "They look to run on anything; a rebound, steal or inbounds pass. And they have three or four players on the break every time. We like to run, too, but we don't run like that."

The Lakers are able to fast break so well because they rebound so well. In the opening game, Magic Johnson had 14 rebounds, Wilkes 10, McAdoo and Kareem Abdul-Jabbar seven each as they outrebounded Philadelphia, 50-41.

Andrew Toney, who is matched against Johnson defensively, had trouble containing the Lakers' 6-9 guard when he grabbed rebounds and took off down court. That's the matchup the Lakers probably will profit from the most in this series.

Toney had eight points in the first quarter, then twisted his left ankle. In the third quarter he twisted his left knee, but returned to score 10 of his 20 points in the final 3:20.

"The knee's fine," he said today. "The ankle is okay, too. They're a little stiff, but they will loosen up and I'll be ready Sunday."

When asked what can be done to slow down the Lakers, Toney paused, almost as if he had doubts it could be accomplished.

"If I could pick one problem we had, it was that we took some bad shots and that enabled them to get out and go," he said. "The thing that makes them so tough is that it's not one person who runs the break. Sometimes it's Magic, sometimes it's Nixon. Sometimes Magic will swing it out to (Michael) Cooper and he'll take it.

"They have a lot of weapons, but so do we," Toney continued. "This series isn't over. That was just one game. We can't dwell on it, we've got to look ahead."