Thirteen years into his professional basketball career, the truth can finally be told about Shaquille O'Neal.

He is not of this earth. On the first day of training camp this year, O'Neal told a group of reporters, "I'm going back to the old Shaq. I was normal last season. I was an earthling. Now I have to go back to my alien roots."

For O'Neal, 33, who joined the Miami Heat in 2004 after eight seasons with the Los Angeles Lakers, getting in touch with his inner extraterrestrial means making virtually unheard-of decision in the world of professional basketball: He's working on adding weight-muscle, not fat-to his already colossal 335-pound, 7-foot-1-inch frame.

That's not a misprint. Goliath wants to be even bigger. Why? Because O'Neal says that when he is heavier, he is a better player. "Last year I was just too nice," that is, too weak, O'Neal tells WebMD. "I came up real light … but now I have to go back to what I know."

That kind of thinking flies in the face of conventional wisdom-not only among many athletes but for the rest of us, too. If anything, most of us battle to lose the seemingly inexorable weight creep that comes from too many indulgences and not enough exercise over the years.

But even a fine-tuned athlete like O'Neal still has to approach the whole topic of weight intelligently. For one thing, he can't just live off a high-calorie, high-fat diet to add pounds-or at least not without undesirable consequences. His philosophy pivots on healthy nutritional choices with an occasional allowance of his favorite sinful foods.

Heavy Duty
For a man of his size and agility, O'Neal is nearly without peer in his ability to both plant an opponent into the front row and outrace him to the other end of the court.

The 12-time NBA All-Star and three-time NBA champion, as well as the holder of an Olympic gold medal, is "a unique athlete," says Cedric Bryant, PhD, chief exercise physiologist with the San Diego-based American Council on Exercise. "He has that blend of speed and strength that allows him to be so powerful."

And while gaining weight late in a career might seem foolhardy, Bryant says O'Neal has conditioned himself physically and, just as important, mentally to operate at a large size-one that is uniquely suited to his MO.

"I think it really affects Shaq psychologically when he has attempted to play lighter," says Bryant. "He just doesn't feel like he's Superman. When he has that extra bulk and mass, he's unstoppable out there."

After an injury-plagued first season in Miami, which caused him to miss nine regular-season games and a pair of playoff contests with a thigh bruise, O'Neal says he spent the off-season working out at his Miami home with his bodyguard in twice-a-day sessions. The result: He added 15 pounds to his frame to weigh in at 335.

These workout sessions may have also served as a catalyst for his latest off-season endeavor. Over the years, he's been a rapper and an actor in his spare time, but now he's teamed up with 24 Hour Fitness USA to create Shaq Sports Clubs, complete with Shaq-sized amenities such as swimming pools and, yes, basketball courts. The first of these gyms opened in Miami in 2005.

Still, even while the patrons at his new gyms are trying to sweat off the extra pounds, he hints that he'd like to pack on an additional 15, which would put him at 350. Like many athletes, O'Neal is sensitive about his weight and is upset about talk that he is-or ever has been-overweight, contending that the Lakers, in an attempt to lowball him in contract talks, put out the word that he was out of shape.

"Everyone always [says] that I have a weight problem,'' says O'Neal, who wears a size 23 EE sneaker, size 52 shirt, and size 48 shorts. "You have to understand that when you're talking about weight, muscle weighs more than fat." While this belief is widely held, it isn't exactly true-and most of us are not brave enough to argue with O'Neal.

But his recent weight gain, O'Neal is quick to add, is all muscle-not fat.

"Have you ever seen a weight lifter or a bodybuilder?" he says. "Every wrestler is 360 or 370, but they're all muscle and no body fat. Most of my weight is muscle. I have big feet and big arms. I have really strong quads. I've never had a weight problem."