"I'm doing well, man," the 7-footer said during a news conference at the Lakers' practice facility. "The knee's good. Everything's ready to go, 100 percent. I've been training, getting stronger."
He was in the midst of a breakout season when injured, averaging 13.1 points and 10.1 rebounds.
Bynum recently returned to Southern California after spending a month working out with his personal trainer, Sean Zarzana, and former NBA standout Gerald Wilkins in Atlanta.
Bynum, the 10th overall selection in the 2005 NBA draft, credited the rapid improvement he made last season to the hiring Zarzana in the wake of withering criticism from teammate Kobe Bryant after the Lakers' first-round playoff ouster in 2007.
"Actually, I'm better," Bynum said when asked to compared his fitness to last summer. "My times on the track are better and I'm able to lift more weights. I'm stronger. I weigh about the same, I'm 285 [pounds] with less body fat."
Bynum said he looked forward to working with Lakers legend Kareem Abdul-Jabbar again this season. Abdul-Jabbar, the leading scorer in NBA history, has served as a mentor to Bynum, who jumped from St. Joseph High School in Metuchen, N.J., to the pro ranks.
"I can't wait, man," Bynum said. "I think I'm the only guy who wants the season to start, like, tomorrow, you know what I mean? But I just can't wait to play with the fellows."
Bynum is eligible for a contract extension that could pay him up to $80 million for five seasons, but said he's not thinking about anything but a successful return to the Lakers' lineup.
"If I handle my business on the court, the business off the court will be handled," he said.
Bynum also said he's looking forward to teaming with Pau Gasol, who will move from center to power forward this season.