IT COULD have been a planned workout.

Nothing is unusual about several Flyers riding a bike or lifting weights after a game, good or bad. But there is something about the way nearly the entire team was hunched over the bikes in the workout room, peddling furiously, dripping sweat, as if they felt as if they owed it to someone.

It looked a little like detention.

A 5-2 loss to an Ottawa team having a bad season that had just fired its coach, Craig Hartsburg, and was playing on back-to-back nights has a way of doing that to players who were coming off a four-point weekend and had 4 days' rest.

"Teams below us in the standings, you have to beat each and every night," defenseman Randy Jones said from his bike. "I think we underestimated them a little bit, because they are playing so well right now.

"They've got a new coach and learned some new systems and whatnot, but I mean, they have nothing to lose, they're going out and playing hard very night, and I don't think we took them as serious as we should have.''

That might have been the case last night. The visiting Senators might have looked like an easy two points. They came in last in the Northeast Division, a full 19 points behind the Flyers.

But they also were coming in on the verge of their first three-game win streak since March of last year, having beaten Buffalo twice in a row.

Despite allowing 36 shots on rookie goalie Brian Elliott, the Senators put a hurting on Antero Niittymaki and the Flyers.

Niittymaki, who had two big wins over the weekend, allowed five goals on 23 shots, including one with 13.8 seconds left in the second period when Nick Foligno caught him on his hands and knees and put the Senators ahead, 3-0.

"I thought that he was going to shoot it and I went down and I couldn't get there anymore,'' Niittymaki said. "It was pretty embarrassing. I just wasn't really sharp tonight, and that's it.''

Mike Richards, back after missing three games with the flu, scored late for the Flyers, along with Darrell Powe, but it wasn't nearly enough to make up for some missed opportunities and flat-out lapses that opened the door for Ottawa.

"Give them credit, they played well, capitalized on pretty much every opportunity they had,'' Richards said. "I thought we had some chances, especially in the second period on the power play and didn't score, and maybe a couple of good bounces for them, off the post and in, off a foot and in. Disappointing? Yes. But I didn't think we played too, too bad.

"You're going to have games where you think you deserve to win and you lose, and you're going to have games where you shouldn't win and you win. We definitely had the opportunities to get some goals.''

The Flyers got off to a shaky start and ended up falling behind on a double bad-bounce goal.

After Ottawa backed the Flyers in on a rush, Dany Heatley blasted one from the top of the right circle that hit the post. The rebound came across the crease, hit Scott Hartnell's skate and then deflected off Niittymaki's skate into the net 18:22 into the first period.

Ottawa jumped ahead, 3-0, after the Flyers did everything but roll over.

Riley Cote took a bad tripping penalty, putting the Senators on the power play. Jason Spezza was standing by himself at the open side of the net when Brendan Bell slipped a pass through the crease that hit Spezza's skate and went in 8:40 into the second.

The worst goal in a long time followed. Ottawa went offside and cleared the zone. The Flyers just dumped the puck around the boards where it was picked off, allowing Ottawa to transition in with possession, the Flyers out of position. Foligno walked the puck in to the net and slipped a backhand shot behind Niittymaki for the 3-0 lead.

Powe got the Flyers within two goals when he popped in a rebound off a Scottie Upshall shot 8 minutes into the third, but there was no comeback. Heatley took a shot from just inside the blue line that went right between Niittymaki's feet at 10:15.

Richards scored at 10:54 after being led into the zone on a long pass from Mike Knuble, but Antoine Vermette then scored unassisted, the fifth goal on 21 shots for Ottawa.

The Flyers have just a day to rest before hosting the Islanders, the worst team in the league, and then are at Madison Square Garden Sunday afternoon to face the Rangers, who have struggled the last few weeks.

"You always go into a game thinking you're going to win this game, but somehow it seems for us that 4 days off is never good. We almost play better when we play back-to-back games or every second day,'' said defenseman Kimmo Timonen.

"Personally, I like that. Four days off, you think you're rested but . . . I don't think we played bad. Maybe in the second period, we could have done a better job. We have to give them a lot of credit. Their goalie played well.'' *