(FORTUNE Magazine) -- Welcome to the bod pod," chirps Amanda Evans, who is manning the six-foot-high egg-shaped capsule. Step inside the pod, and it measures your body-fat ratio - a figure that could hold no terror for the fit and athletic Evans.

Face the Truth is one of the precepts at the Corporate Athlete Program; but facing the pod was a daunting prospect for many of the 25 or so members of my group, most of them mid- to senior-level executives, at the Orlando-based Human Performance Institute.

The premise of the program is that corporate life demands high-level performance for sustained periods. By managing our energy, promises chairman and CEO Jim Loehr, we will become more "fully engaged," both at work and at home. "Engagement is the window through which we enter life." Loehr says.

Uh-oh. I dread the prospect of three days of group therapy, trust falls, and other squishiness. And then comes Heidi Hanna. As a nutritionist should be, she is slender without being skinny, and immediately endears herself to us by announcing,

"My job is not to take the good stuff away from you." During the next 90 minutes she gives us a primer on food and the human body. It is absolutely fascinating.

You probably know you are supposed to eat every two to three hours (and don't do it). The reason is that if you don't, your body goes into survival mode, chewing up muscle mass and storing fat. That's why skipping meals is no way to lose weight - you really just lose muscle.

The best bet is to eat three small meals, with two or three low-glycemic snacks (a few peanut M&Ms, apples, soy chips) in between to keep up your glucose levels.

As for meal portions, Hanna recommends a serving of meat no larger than your palm. Into an appalled silence, a voice calls out, "How thick?" Answer: the width of your hand.

After lunch - half a chicken wrap, some fruit, a scoop of potato salad (and no seconds) - we move on to fitness expert Chris Jordan. His recommendation is to suffer a little: Exercising to mild discomfort, then recovering, is what builds fitness, not plodding along for hours.

To demonstrate, Jordan lets us each choose a machine (treadmill, exercise bicycle, rower) and puts us through the paces: a warm-up, then 24 minutes alternating between comfortable and challenging exercise in three-minute intervals. Three such sessions a week, plus two sessions of weight training, is enough to keep an adult fit and energetic. And, yes, there are plenty of exercises you can do without a gym. "Damn, there's the last of my excuses," sighs the person next to me.

Complementing the fitness and food experts, Loehr moves on to why we should bother. He begins by praising stress. It is essential to fitness and inevitable in life, but it's important to remember to incorporate rituals of recovery. Tennis players look at their strings between points; executives can roll their shoulders every hour. And stress needs to have a purpose to be useful.

Armed with logs and workbooks, we're pushed to figure out that purpose. A "life engagement audit" helps to identify priorities; evaluations prepared by others prior to the program can spotlight areas of disengagement.

One person, for example, thought she was a supportive boss but found out that her colleagues believed she could do better. It does feel squishy, but, like the rest of my group, who are beginning to bond over the nutrition bars, I can sense the method here - to use the energy boost provided by better diet and exercise as tools to achieve larger goals, such as balancing work and family, or simply enjoying life more.

So what do companies get from this fairly expensive trip ($3,750 per person) down the path of self-realization? It isn't obvious what the payoff is, but Steve Altmiller, CEO of the San Juan Regional Medical Center in Farmington, N.M., is such a believer that he has not only sent dozens of staff members to Orlando but has also established an in-house program based on Corporate Athlete principles. He credits it with helping to retain employees.

A more energized workforce, he notes, is also less likely to make mistakes. And he has noticed a boost in morale: "At least once a week I have an employee thanking me for it," he says. Procter & Gamble (Charts) has sent hundreds of people to the course - including CEO A.G. Lafley.

Kirk Perry, a VP at P&G, and 80 members of his team completed the program. Perry says a six-month follow-up found that 80% "had some specific, measurable improvement in their lives."

A survey of eight members of my group - including two who paid their own way - was uniformly positive. "The program was concrete: 'If you do this, then you will have results.' And it worked for me," says Tee Persaud, an Orlando lawyer who lost ten pounds and lowered his cholesterol.

The Starbucks (Charts) gang of five, who took the course together, report a generally more positive outlook and one member whose waist is slimmer by two belt notches. "We're definitely more in sync," says one of them, Brent Hayward. The last time the crew went out to dinner, he says, they all watched one another's menu choices.

While I kept resisting the squishiness - and like others, wished Loehr had not read the personal statements, even anonymously, that the group sent before the course - I also came away with respect for the approach. On the days when I follow the food guidelines, I no longer suffer a midafternoon slump. And I did appreciate the opportunity for structured self-examination. Have I turned into a full-fledged Corporate Athlete? Let's just say I'm still in training.