Sure, they're great for some, but these workouts are hiding something. Consider yourself warned


Infomercials make every exercise program look amazing, and there's no doubt they can work for the folks they fit-if you love a program enough, you'll stick with it, get results, and maybe even see your before-and-after mug gracing the screens of late night.

But those half-hour call-now sessions hide things, too: little inconveniences, pseudo-scientific babble, and just plain weird stuff that every consumer should be aware of before paying shipping and handling. Consider these your public-service warnings for six popular programs-they may not be deal breakers, but at least you'll know the full story before you fork over your cash.

Insanity Workout


Disclaimer: Your downstairs neighbors may be the ones to go crazy.

Insanity is, in many ways, amazing: It reproduces the at-home intensity of P90X, but with shorter workouts (35 minutes versus more than an hour for P90X) and without expensive equipment like dumbbells and pull-up bars-basically, the barriers to entry have been smashed, and replaced with intervals of pushups, squats, and LOTS of jumping.

That jumping can be worth every hop: In a study from 2006, researchers from Western Michigan University and UT-Arlington found that a six-week plyometric (jumping) regimen improved athletes' agility compared to those who stayed flat-footed. And while you may not need to juke away from a defender, that agility can help you when you're trying to avoid a pothole while running, or when you need to weave through a crowded concert to find your friends in the front row. Plus, the pounding of plyos can also increase bone density.

But that pounding is also the rub: The up-and-down slamming of so many jumps can, with the wrong form, increase the risk of ACL injury, which is already 8 times more prevalent in women than in men. See a doctor before you start this program to be sure your knee is tracking correctly. And then go downstairs and talk to your neighbors-Insanity's high flying might melt away fat, but it may also land you in a meeting with your landlord over all that thumping on their ceiling.

Hybrid Spinning Class


Disclaimer: Those aren't pushups. Concentrate on your cycling.

Somewhere in the middle of your Spin class, while you're sweating through your shirt (good) and your quads are on fire (good), your instructor might tell you to get out of the saddle (good) and start performing "pushups" on your handlebars.

Not good: Those aren't pushups. Your position only allows you to press a tiny fraction of your body weight, and the fact that it's all upper body ignores the pushup benefits to your core, butt, and legs. The range of motion is restricted, too, which science says isn't good: In a study published in 2010 in the Journal of Strength & Conditioning Research, scientists found that a decrease in range of motion was associated with a decrease in muscular recruitment.

So concentrate on your pedaling. And when you get home, work on your upper body while your post-workout shower warms up: Drop and do a set or two of full-range, total-body pushups before you hop in and clean off.



Disclaimer: Your legs and butt will shrink (and maybe not in the way you want).

The workouts of Tony Horton's DVD series have created a legion of abs-wielding self-photographers, but those pictures are usually taken from the waist-up. For many women, a hard tush and strong legs are as important as wicked shoulders and chest. And the schedule of P90X may not be ideal for achieving those results.The trouble is frequency: In both the "Classic" and "Lean" schedules of the program, legs are only trained with weights once per week (on day 5), and even then, it's combined with a pulling-heavy back routine. Science shows you need more: In a 2003 study from Arizona State University, researchers determined that beginning exercisers had the best strength development responses by training a muscle group three days per week; advanced exercisers got the best results from two training sessions per muscle group per week. So if you want better legs and butt, supplement your X routines with some SQ&L-squats and lunges.



Disclaimer: Not all gyms are created equal.

There's no question that for the right kind of person, the frenetic pace and screaming encouragement of a CrossFit workout can be transformational-scores of women have grown stronger and more confident from these ultra-competitive spaces.

But you want all those shouts of goodwill because you're doing the exercise correctly-with the skill required to do the highly-technical Olympic lifts that make CrossFit so great, not just because you muscled a weight up by any means necessary, setting yourself up for injury, or at least not for strength. (Want an extreme example? Google "The worst weightlifting video in the history of weightlifting videos.")

It's all in the gym (or, in CrossFit parlance, "box") that you choose. Most locations will help you learn the strict form necessary to perform cleans, snatches, squats, ring dips, and other exercises in ways that will keep your shoulders, knees, and back safe. Look for a box where the instructors have a complete health and fitness background-certifications from nationally recognized groups like NASM, NSCA, or ACE, as well as degrees in physiology or kinesiology. And see if the box you're looking at has an On-Ramp program: These starter courses will drill you in the more complicated movements of CrossFit using light weight or virtually weightless PVC pipe, so when there's weight on the bar, your body will know how to move (and you won't wind up on Tosh.0).

The Tracy Anderson Method


Disclaimer: You WILL gain muscle (and you may get some weird looks in the process).

The low- or no-weight dance-like moves of Gwyneth's famous trainer are supposed to target oft-missed muscles-the gluteus medius, which can help keep your knees from caving in and causing injury, and the lower trapezius, which is missed by many shoulder programs and can keep your scapula safe.

Anderson targets these (and all) muscles without much weight so you don't get "bulky" (she espouses a three-pound limit on load). It should be noted that science doesn't back up this claim: In a study from 2010, Canadian researchers found that exercisers who performed low-load, high-volume exercise (that is light weights, high repetitions) increased protein synthesis more than those who did heavy weights for low reps-and more protein will eventually lead to bigger (read: "bulkier") muscles. However, as a woman you're unlikely to develop excessive bulk, so the muscle gain will likely be subtler than it sounds.

Still, in order to increase intensity with these light weights, Anderson's method requires you to increase the speed of your movement-resulting in a lot of flailing motions that don't look so graceful when done by non-dancers. So unless you want your neighbors to call in the men in white coats, draw the curtains when you pop in Tracy's discs.