It was 85 degrees, the humidity was high and all around the Mount Vernon Recreation Center were these big guys wearing long underwear and wielding sticks. The Washington Capitals had returned.

"Perfect hockey weather," Coach Bryan Murray said.

He wasn't kidding. Now that the Capitals have Frank Costello as their first strength and conditioning coach, any weather is good hockey weather.

Costello, who works in the same capacity at the University of Maryland, was hired by the Capitals just before the end of the 1986-87 regular season. He spent his first few weeks talking with the players and watching how they move on the ice.

Then, after consultation with people who have worked with hockey players before (including, he said, a number of former Soviet coaches now living in the United States), Costello developed a course of offseason action.

Yesterday, the first day of training camp, was examination day.

"I feel like I'll be ready to become a track and field star after I get done playing hockey," said Craig Laughlin, one of the players who tested well in the vertical jump and standing long jump (tests that indicate the level of quick-acting force in an athlete's lower body), sitting 12-pound medicine ball throw (quick-acting force of the upper body), 175-pound bench press (upper-body "pushing" strength) and for hamstring and shoulder flexibility and lateral agility.

The players were also given the "quickometer" test (measuring speed over five yards to the hundredth of a second).

"It is something of a minidecathlon," said Costello, "but that's the idea: to make them be better athletes."

"It's something we've been looking at doing for a couple of years," Capitals General Manager David Poile said. "It was a just a matter of locating the right person."

That's something the Philadelphia Flyers did a number of years ago when they hired Pat Croce, a conditioning expert who, like Costello, works with athletes in several sports. "We want to remain as progressive as we can," Poile said.

"There's no question in my mind that it is an advantage in having an expert in physical training working the team," Costello said. "The game is too sophisticated now for the players and the coaches to know everything about the game and the training for the game. If Philadelphia has a guy and the Capitals don't, that gives Philadelphia an advantage."

And how much has that gap been bridged now that the Capitals have their man? "I don't know," Laughlin said. "But the things we're doing seem more related to hockey than before and I think that whatever we do this season, part of the credit is going to have to go to Frank."