Marietta Gilman, 28, was an aerobic dance instructor for various studios in Los Angeles until one bounce too many cost her a torn hamstring muscle.
Now Gilman teaches her own system of "low impact" aerobics at the Voight Fitness Center in Hollywood. It gets the heart going, as well as the spirits, without the jarring bounce, pound and kick of traditional aerobic dance.
Often called "non-compressive," "lite" or "soft" aerobics, the move away from the high intensity and "feel-the-burn" mentality of aerobic dance is catching on quickly in the fitness field.
Even Jane Fonda's new tape has been considerably "softened." And for good reason: The impact of landing on the floor with as much as three times their own body weight has proven too much for a lot of people's feet, knees and backs, leading to thousands of injuries.
Seeking a safer way to exercise, many aerobics instructors are turning to new techniques. Gilman uses a combination of martial arts and dance. She strives to keep things close to the ground, using several large muscle groups simultaneously and striding patterns across the floor.
Weights, Rubber Bands
Other studios, like Body Express in Hollywood and Elan in Brentwood, have incorporated light weights and big rubber bands into their classes.
"We found that with the bouncing style of aerobics, momentum took over and we weren't really working so much," explained Linette Savage, author of "Muscle Aerobics" and instructor at the Exercise Co. in Sherman Oaks. "Low impact requires a lot more work."
Even the YMCA in Hollywood has added "Lite Weight Aerobics" to its schedule. "We don't want instructors pushing all the people in their classes to the same level," said Woody Cox, health and physical education director for the Hollywood YMCA.
Initially, aerobic dance was designed as a fun route to cardiovascular conditioning. The idea was to raise the heart rate to a target that fit a person's age and general condition. By increasing the heart's pumping capacity, it grows stronger. Aerobic dance was not intended as a "I-can-kick-higher-than-you" contest.
In fact, Lorna Francis, a San Diego State physical education lecturer, maintains that high-intensity aerobics may be self-defeating.
"When dancers exceed 75% of their maximum heart rate they might get some additional cardiovascular benefit, but they increase their chances of injury dramatically," explained Francis. "It comes down to the law of diminished returns."
And surprisingly, if you are looking to lose weight through aerobics, as most people are, Francis advises sticking to the low-intensity variety. It is a more efficient fat burner, where a high-intensity workout burns off carbohydrates, she said.
The National Injury Prevention Foundation and San Diego State University recently conducted a survey of 135 aerobic dance instructors in Southern California.
They found more than 76% of the instructors incurred or aggravated at least one injury through aerobic dance.
"Our second most frequent patients are aerobic instructors," said Dr. John Pagliano, a Long Beach podiatrist who served on the medical crew for the Italian Olympic Track and Field team.
Aerobic injury, many experts agree, depends on three things: floors, shoes and technique.
"Floors should not be too hard, nor too soft," warned Francis. A suspended wooden floor is considered best. Wood over cement is virtually the same as pounding on bare cement.
Shoes should not be too soft.
Instructors and technique are a more subtle and subjective matter.
Also look at your own body, warned Dr. Allen Selner, a Sherman Oaks podiatrist who specializes in sports medicine. "Bio-mechanics," the structural faults inherent in each individual's anatomy, contribute substantially to injuries.
One of Selner's patients, Barbara Bau, 51, has been an instructor with Jacki Sorensen's Aerobic Dance in Granada Hills for four years. She developed severe pain from "pronated" ankles--ankles that pointed toward the floor instead of to the sides. Selner removed scar tissue, then designed inserts called orthotics that correct the way her foot lands on the floor.
The Jackie Sorensen program is "perfectly safe," said Bau. "I had a genetic problem that needed correcting."
"Techniques that work well on one surface might not work on another," commented Dr. Alan Strizak, an orthopedic surgeon with the Sports Trauma and Athletic Rehabilitation Center in Fountain Valley. "The low-impact, side-to-side moves can be disastrous to people who are wearing traditional running shoes built for moving forward and backward."
There are some exercises, said Francis, that have been proven to be "contraindicated" (poor as far as the anatomy is concerned). Straight-legged leg lifts for the abdominal muscles are stressful on the back, neck and promote "lordosis," or sway back. And they do little for the stomach.
Sit-ups more than 20 degrees from the floor endanger the back and any stretch that is not static, but bouncy in nature, is contraindicated.
What is the bottom line for aerobic safety and effectiveness? "People should scrutinize their fitness instructor the same way they would scrutinize a teacher for their kids," warned Karen Bauer, executive vice president of the National Injury Prevention Foundation.
But even with the availability of low-impact aerobics, experts claim some things stand between exercisers and improved safety.
One is a licensing system for fitness instructors--a State Senate Bill (SB14) currently pending.
But the biggest stumbling block might be the exercisers' own belief in "pain."
"Aerobics shouldn't make you sore. But some consumers, especially men, think they have to be sore to get the benefit," commented Strizak. Added instructor Gilman, "People are going to have to realize exercise doesn't have to hurt to be beneficial."