Fitness trends come and go — does anyone remember mini-trampolines? — but my continuing interest in them has no bounds. What's hot and what's not for 2011? Is Pilates going the way of the Hula Hoop? Is modern technology killing off full-service gyms? Or is "C U @ Zumba class@6" responsible for the upswing in small group exercise?

Crystal ball gazing is not an aerobic sport, but it's extremely popular with fitness organizations, so let's review some of their hard-core predictions for the coming year:

ACE — the American Council on Exercise, the largest nonprofit fitness certification, education and training organization in the country — is spinning a very optimistic outlook for 2011. Consumers are sensing an economic upswing, according to an ACE survey of more than 2,700 fitness experts. This is motivating adults (and youngsters!) to get to the gym and spend more time with personal trainers.

Since ACE is an organization that certifies personal trainers, I must warn you that this prediction is entirely self-serving. That's OK. Sometimes trends can be motivational. You start exercising — finally! — because you think all your pals are getting serious about fitness and you don't want to be left behind ... (as in big behind.)

ACE also predicts for 2011:

— STRESS REDUCTION THROUGH FITNESS. Consumers are getting wise to stress and the terrible toll it takes on your body. In 2011, more gyms and clubs will offer classes and strategies to help their clients handle stress in healthy ways.

— SMALL-GROUP WORKOUTS. Small-group sessions grow every more popular for three good reasons: They save people money; they allow people to socialize; and they keep people motivated, especially older adults badly in need of a high five.

— TECHNOLOGY BECOMES A SUPPORT RESOURCE. Online interactive classes will not proliferate in 2011, says ACE. Why? Because there is "a desire for human contact with fitness professionals." Social networks like Facebook and Twitter will grow in popularity because they serve as motivational tools and online support systems.

The American College of Sports Medicine (ACSM) is another large organization of health and fitness professionals, also in the business of making fitness predictions for 2011.

The one that got the most attention this year? The fall of Pilates. For the first time in years, Pilates did not get a mention in ACSM's top 20 trends, prompting George State University fitness expert Walter R. Thompson to say he's not at all surprised.

"Pilates requires some specialized training," says Thompson, who claims he felt all along that Pilates was "more a fad, than a trend."

Pilates is passe? I can't help but think Thompson is posturing. Pilates is a fantastic way to train your body and your mind, and develop core physical strength. If it's passe, I give the trend toward kettle bell training less than a year.

Here are two more of the ACSM fitness predictions for 2011:

— MORE FITNESS PROGRAMS FOR OLDER ADULTS. This is neither a fad nor trend — it is a no-brainer. Aging baby boomers have more discretionary dollars to spend than younger people, and they want to live forever and a day. (These aging boomers are also suffering rising numbers of sports and exercise injuries, which just goes to show you that some fitness trends are bad news.)

— MORE BOOT CAMP. This trend is a shoe-in. Military-type fitness training is high-intensity, and incorporates cardiovascular, strength, endurance and flexibility drills in indoor and outdoor settings. It's not for everyone, but what is?

And finally, here are some predictions for 2011 from the Preston Institute of Fitness Forever & Lifelong Energy (PIFFLE):

— In 2011, sugary colas and their fake sugar equivalents will be sweetly taxed, driving consumption way down. In spite of the beverage industry outcry, thinking adults will cheer.

— Physical education and recess will return to all public schools, and yoga and meditation classes will be required for graduation.

— Bicycling tax credits will be given to adults who bike to work. Students who bike to school will win time on their cell phones, otherwise locked up.

ENERGY EXPRESS-O! WHY FITNESS CLUBS ARE ON THE MAT

Up to 45 percent of fitness-club members quit in any given year, and thanks to all those flat-screen TV's and iPods, the attrition rate is growing.

"Now everybody's plugged in. In the '70s, they came for community. Now, they come and disassociate from everyone in the club. It's killing the health club." — fitness consultant Jonathan Fields

Marilynn Preston — fitness expert, personal trainer and speaker on healthy lifestyle issues — is the creator of Energy Express, the longest-running syndicated fitness column in the country. She has a website, http://marilynnpreston.com and welcomes reader questions, which can be sent to MyEnergyExpress@aol.com.