Susan Harmsworth has redefined the luxury spa for hotels like the Four Seasons and The Peninsula. Here, she talks about why masseuses are like chefs and what it's like to collaborate with Alain Ducasse.

Susan Harmsworth, founder of the England-based company Espa, has been instrumental in the transformation of spas from no-frills health farms to luxurious retreats. Since its debut in 1993, Espa has created innovative spas for top hotels around the world. Recently, Harmsworth and her staff have been especially busy, completing the Gianfranco Ferré spa in Milan, and the hotel spas at the One & Only Reethi Rah in the Maldives, The Peninsula in Hong Kong and the G in Galway, Ireland.

Here, Harmsworth—a frequent traveler and an avid wine collector— discusses why some spas make a powerful impact on their clients' well-being and some don't, and why great chefs have so much in common with massage therapists.

How have spas evolved over the years? There have been enormous changes since I started out in the industry, as a writer covering beauty and women's issues for Vogue and Nova in the 1960s. In those days spas were much more clinical. At the European clinics, or the original English "health farms," you used to go for a minimum of seven or 14 days. And you'd suffer and starve. It was all under very strict supervision.

Spas are offering custom treatments nowadays. How do Espa therapists decide on the best treatment for each person? At our spas, we train all the therapists to look at your body shape and how you speak, how fast you walk. The therapists put questions to you like, "Do you like dry heat? Do you like humidity? Do you like cold? What kind of food do you like?" This way they get a whole view of you as a person, so they can better treat you. Then we "mood-set" your treatment room. Your olfactory senses are different day to day, so we do smell tests to see what mood you're in. We do color tests too, to see if you might prefer a calming green environment, for instance, or an energizing orange one. We try very hard not to jar any of your senses. We have heated blankets available for the beds, but some people can't stand that, because they're "hot" people. We design rooms in a way that allows us to instantly change the temperature. And the rooms are well-ventilated, to avoid any lingering smells in the treatment rooms; you need fresh air.

Which Espa treatments do you consider the most innovative? At the Mandarin Oriental Hyde Park in London, we offer something called the Orient Joint Release (Life Dance Ritual is our other name for it). It's a rocking, shaking, two-hour treatment that works on the whole body. It includes a foot massage, a head massage and a ritual of stretching the body and rotating the joints to release bad energy. Four-handed massage, with two therapists working on a client simultaneously, has become very popular worldwide now, and it's usually quite basic, but our version isn't basic. Our therapists start at opposite ends of the body. The idea is to confuse the brain so you don't know what's coming next—because people who have regular spa treatments tend to anticipate movement. With our technique, as the movements proceed, they really do have a releasing effect, because your body is not adjusting for it.

What role does the staff play in keeping guests happy? Spa staff have to be well-trained and caring. We train our staff to get in the habit of walking slowly in the treatment areas. In certain cultures, that's bloody difficult. Imagine in Moscow, trying to calm them all down. Hoteliers tend to think, "Oh that's the spa over there. The staff is always calm because nothing ever happens." But actually we're stressed out since we're taking on everyone else's stress.

What role do chefs play in your spas? I'm dealing with Alain Ducasse at the minute. I'm doing the spa at his Tuscan inn, L'Andana. He's talking about doing little, er, I don't know what he would like to call them, but delicacies of some sort tied to local ingredients. We've got rosemary, citrus and olive oil and all the obvious things in Tuscany. And he wants to do little gourmet bits and pieces to match the treatments we'll be using. For instance, he's doing a soy-milk panna cotta with seasonal fruits for clients who have a facial, and a lavender tart for those having a hot-stone massage—and he's doing infusions of rosemary, thyme, wild fennel and lemon balm.

I'll tell you what's very interesting, from a food-and-wine point of view: Chefs and spa therapists are amazingly compatible! Take chef David Nicholls at the Mandarin Oriental Hyde Park; his fiancée is one of my trainers. My spa director at The Peninsula in Hong Kong is engaged to a chef. I've got loads of trainers who are either married to or living with chefs. They just tend to be very similar people who have a passion for ingredients. I can't remember where I was recently, but it was a very male environment and the chefs couldn't wait for all the therapists to arrive.

I understand you're a wine lover. I collect wine. I buy wines at Corney & Barrow or Berry Brothers & Rudd in London and also at auctions. My father was a Francophile, so I was sent to spend a summer in France at the age of 12, which for my generation was unusual. I went to the Haute Savoie, to stay with a family who owned a hotel and to learn French. And my father was an absolute winey, so I grew up drinking wine; I think it must have been from about age 12, because in those days they used to think the odd little bit of wine was good for children. As I got older and I went to live in the States for a few years, I always had wine in my life. I went New World when I was in America, and I've tried a lot of Australian wines. I love trying new wines, but I've gone full circle, back to French wine. I still like the old names: Drouhin, Bouchard Père, Jadot.

How do you stay healthy and sane when you're traveling constantly? I always travel with Bose headphones, cashmere socks and a pashmina. Besides that, I try to stay calm. I'm a very easy traveler. If the plane's late, I take it very much in stride. I often don't eat, but I will have a glass of wine before I go to sleep. I drink masses of water. On a long-haul flight, I try to work a third of the time, sleep a third and play a third. I quite like to work on flights because it's one of the few times you can be creative and read properly. I really dread the day when they get BlackBerrys to work in-flight; that's already happening. When I arrive, I sleep when I feel I can; I'll often sleep for a few hours, even if it's 9 p.m. If I grab a couple of hours here and there, I find I get back on schedule better that way. My average stay is two days, so it's no good trying to adjust to a time zone. Also, stretching is important when you've been on a plane. I believe you should move as quickly as you can once you're off—walk or go to the gym.

What are you working on now? We have a big year ahead of us, with 20 openings. We've got the Hotel Metropole in Monte Carlo coming up soon. It's dramatic: a glamorous hotel, refurbished by Jacques Garcia and with Joël Robuchon as chef.

The spa has dark-wood floors and lovely [Italian glass] Bisazza tiles. It's very moody and beautiful. And we've got the Bulgari Bali, designed by Antonio Citterio, which opens in October. It's an amazing site on a cliff. The spa pavilion is an antique Javanese hand-carved joglo house [a traditional teak Indonesian building].

Are there any spa trends you find annoying? I'm not into marketing gimmicks. In our industry those are very prevalent. With all due respect to marketers, they tend to think every spa has got to have a signature treatment, something to hang its hat on, so they dream up something that sounds wonderful but actually has no physiological benefit. A chef wouldn't do that—at least not a good one. He'd say, those things don't go together, don't be ridiculous, they can't all be on the menu.

What trends do you foresee? We'll probably see more destination spas where there's no TV, no telephone, no electricity. I think that approach is going to make a comeback. We might even see places where people have to build their own fires—something that addresses the need for grounding, because we're so technologied out. But the spas are going to have to be at such a high level. Reethi Rah's the start, although it's also a glamorous resort. I think retreats will come back. Some of these shifts have to do with spirituality, or whatever you want to call it. Not religion, not therapy—but the spa has got to have a soul. A difficult subject, that one.

Jeremy Wayne, F&W's U.K. correspondent, is the restaurant editor of Tatler.