I learned early in my career as a fitness editor that you can't trust celebrity trainers.

Most of the ones I worked with at Men's Fitness were affable and accommodating, giving me the type of material I needed for the magazine. But I quickly learned that their personalities were sometimes more important to their ability to get and keep famous clients than their actual training skill.

I also noticed an odd pattern: Sometimes, if a celebrity had achieved a remarkable physical transformation for a particular movie role, more than one trainer would take credit. Other times, trainers would tell stories behind each other's backs about how so-and-so trained his star client with a little help from the pharmaceutical industry. (In one instance, which I recounted here, the trainer told that story on himself.)

I once asked one of Joe Weider's old-school buddies about training celebrities back in the day. He told me that movie stars, under contract to studios, were expected to go out to nightclubs and drink every night. The Hollywood publicity machine depended on it. Since the stars also worked year-round, going almost directly from one studio film to the next, there was no time built into the schedule for the actor to get into shape when a role required it. The trainer who got the assignment to turn the pasty, flabby actor into the he-man that audiences expected him to be often found that his best training tool was a bottle of amphetamines.

This trip down memory lane was prompted by this odd article about a celebrity trainer named Rob Parr, who has some unflattering things to say about the bodies of his clients when they first came to him:

If you read carefully, you'll notice that Parr's first name is misspelled in the news report, and if you go to his website, you'll see that he's been in the training business for a long time. (His bio says he played himself -- a gym manager -- in the movie Perfect, way back in 1985.)

Being an O.T. (Original Trainer) gives him some leeway in claiming to whip celebrities like Madonna into shape. I mean, we can find plenty of visual evidence that early-career Madonna was a little fleshier than the fitness animal she later became.

But when I worked at Men's Fitness in the mid-'90s, I worked on a couple of stories with a trainer named Ray Kybartas, whose claim to fame was the fact he trained Madonna. And we had to be careful to distinguish him from yet another trainer, Carlos Leon, who fathered her daughter Lourdes but never actually had Madonna as a client.

My point? Actually, I think I have three:

• It's hard to say exactly who deserves credit for any given celebrity's physical development. It's generally a combination of multiple factors, including the celebrity's genetics and willingness to train hard, specific circumstances (like the amount of time they had to make the transformation), and perhaps something that was produced by a pharmacy in Mexico. A trainer's talent certainly comes into play, but there's no telling to what extent.
• The skill set needed to train celebrities successfully is different from the one needed to train regular folks. Sometimes the ability to get along with famous people, including the ability to put up with their personal bullshit, is more important than training skill and knowledge.
• Celebrities have to look a certain way to make a living, just as athletes have to perform at a certain level. They also have a lot more time and resources to devote to training, nutrition, and recovery. Any of us could look better with the undivided attention of a trainer for several hours a day and with every meal planned by a professional nutritionist and prepared by a personal chef.  

That doesn't mean a trainer banking on his success with celebrity clients can't write a useful fitness book. He might; he might not. I'm simply noting that the very thing he's banking on makes it less likely that he really understands what it takes for the rest of us to get into better shape.