SoulCycle

Instructor Janet Fitzgerald leads a class at SoulCycle, an indoor cycling studio based in New York. Arm weights are part of the class. (Carolyn Cole / Los Angeles Times / November 23, 2011)

I'm an outdoorsy type, and you won't get me on a stationary bike unless there are a few inches of snow on the ground. But I've pedaled my way through enough indoor-cycling classes to know that instructors need to be engaging and entertaining to keep you coming back.

Which brings me to SoulCycle. It's a hot name in fitness, and it's on its way to Los Angeles. This 5-year-old New York City-based chain of indoor cycling studios became famous for merging upper-body exercises with traditional stationary bike workouts. Throw in some candlelight, a whiff of aromatherapy to cover the B.O. and charismatic instructors shouting encouragement over upbeat dance music and you've got a cardio class with a devoted following.

Some of SoulCycle's followers are folks you may have heard of, including Brooke Shields, Chelsea Clinton, Anderson Cooper and Tom Cruise, according to media reports. What's more, actress and talk show host Kelly Ripa gushed about the place in an on-air segment last year: "This class, SoulCycle, is more than an exercise class. It really is an inspirational class that is as good for your brain as it is for your body." With buzz like this, it's not surprising classes sell out within minutes of being posted online.

SoulCycle is emphasizing the primary thing I've highlighted to my clients and readers: the importance of finding an exercise you love and embracing it with fervor. And it appears to be working. The company has expanded well beyond its Manhattan base. Studios are slated to open in West Hollywood in January and in Brentwood in the spring, with more California locations to follow.

Exercise adherence is all about feeling the love, so what's not to love about SoulCycle?

Plenty.

SoulCycle takes an enthusiastic approach to exercise that I want to endorse. But I give this company a failing grade for exercise physiology and biomechanics. The whole idea of working one's upper body while pedaling a stationary bike is not only counterproductive, it can be physically detrimental over time, according to several experts I talked to.

Unfortunately, neither of the co-founders, Julie Rice and Elizabeth Cutler, is an exercise physiologist or a certified cycling instructor. (Before opening SoulCycle, Rice was a Hollywood talent manager and Cutler sold luxury real estate.) Rice told me they worked with an exercise physiologist to create the routines, but that still doesn't erase my concerns about safety or efficacy.

Rice and Cutler rented an old dance studio in 2006 and made a point of hiring dancers and actors to teach the cycling classes after attending an unaccredited nine-week SoulCycle training program, Rice told me. I browsed through the instructors' head shots on the company website, and most of them look like they could star in a soap opera or an episode of "Glee" (not that I'm in the habit of watching either).

Elements of the classes are scripted — from the lighting to the music to the instructors' performance. "Every class is a mini production," Rice said. "People with a theatrical background can bring value to that production." The laudable goal is to help people see exercise as more than a means to an end and actually enjoy the class while they are taking it.

These classes are based on the theory that it's a good idea to include upper-body exercises in an indoor cycling class, and therein lies my problem with their approach. According to Rice and the many SoulCycle videos posted on YouTube, class participants do push-ups on the handlebars, high-repetition lifting with 1-pound weights and a bunch of abdominal twists, crunches and working of core muscles — all while pedaling. (I haven't been to New York to take a SoulCycle class myself.)

This type of hybrid exercise drives Jennifer Sage crazy. Sage has a degree in exercise science, spent 12 years as a Master Instructor for Spinning (a trainer of trainers), wrote a book on proper indoor cycling technique and serves as executive director of the Indoor Cycling Assn. in Eagle, Colo. She's been railing against this kind of workout for years.

I'm on Sage's side. I think a bicycle is no place to attempt an upper-body workout.

Let's talk specifics about what's wrong with this practice, starting off with calories.

I consider caloric burn to be just about the least important thing exercise does, but it's still worth mentioning. "I think the incorporation of weights and core probably are burning more calories than your regular run-of-the-mill class," Rice told me.

Sage thinks differently. "You're probably going to burn less calories because your power output is going to drop," Sage told me.

I agree. I know that when Rush's Alex Lifeson is ripping out a righteous guitar solo on my iPod and I (stupidly) let go of the handlebars to play along on an air guitar, my leg power decreases significantly. You need a firm grip on the handles to create maximum pedaling power. Replacing this lost power with a variety of upper-body movements isn't going to compensate, thermodynamically speaking.

But that's a minor issue. Lean bodies are made in the kitchen anyway.

So let's examine the training effect of this upper-body workout. To build muscular strength and size, you need to activate your larger, fast-twitch muscle fibers, and this requires heavy lifting. If you can lift a weight more than about a dozen times, you've switched to the smaller, slow-twitch fibers; you're getting an endurance workout.

On the videos I've seen, the slight angle at which SoulCycle has participants do push-ups and core work makes the resistance too light to activate the fast-twitch fibers. As for the use of weights, I'll just quote Sage: "Lifting a 1-pound weight isn't going to do anything. It's useless."