Einstein's parents didn't try to enhance their baby's intellect with infant stimulation cards, nor did Schwarzenegger's mom and dad enroll their toddler in a wee workout program to maximize his strength. Yet today's parents are encouraged to think their toddlers will grow up flabby of brain and body if they don't start them on one of the myriad of baby boosting programs that promise to get children on the road to Harvard or the Olympics before they cut teeth.

Although the better baby movement started by focusing on how to maximize children's intellectual development, the near-cult status of fitness for adults has prompted the infant enhancement movement to go physical -- complete with baby workout videotapes.

What Jane Fonda has done for the thighs of the nation, "Baby BodyWorks" and "Baby Dynamics" hope to do for the diaper set. Both feature maternal-looking instructors who run an amazingly compliant series of children through an array of follow-along exercises.

A major difference between the tapes is that "Baby Dynamics" targets exercises for three distinct age groups -- birth to 6 months, 7 to 12 months and 12 to 18 months. (There is a Baby Dynamics Vol. 2 for children 18 months to 3 years.) "Baby BodyWorks," however, presents one set of exercises geared to babies 4 weeks to 12 months -- which means that the exercises are very gentle. This is fine for a month-old baby, but a 6-month-old of our aquaintance who enjoyed "Baby Dynamics" wouldn't sit -- or lie or stand -- still for "Baby BodyWorks."

Billed as a "motor skills fitness program for infants and young children" hosted by "motor skill development expert" Linda Westin, "Baby Dynamics" opens by congratulating parents for "giving your child a head start on developing all the physical motor skills he or she will use forever as well as promoting communication and bonding between you both."

These skills, the tape assures us, "are not just acquired. They are learned and developed just like reading and writing." Exercises in each of the three age groups are broken down into five areas: Flexibility, eye-hand/eye-foot coordination, balance and perception, locomotor and strength and agility. Each exercise should be done two to three times at least three times a week, the tape says, leaving the unspoken implication that if the child skips a day, it could lead to serious repercussions.

But fortunately, after the pedantic intro, the tape is downright fun. The infant exercises for birth to six months are simple, relaxing activities like face stroking and leg flexing. The crawler activities for 7 months to 1 year are imaginative, using common household items as props -- like a rattle on a ribbon for eye-hand coordination and a wooden dowel the child can hold for a supported sit up. The year-old activities for kids up to 18 months are tougher, including one that uses a low balance beam (a 2-by-4 will do) that the child walks on while holding the parent's hand.

Two favorite giggle-provokers are kickball, in which you pick the baby up by the waist and help him kick a ball around the room, and superbaby flying, in which you lie on your back with your legs bent in the air and support the baby on your shins while gently raising and lowering your legs.

"Baby BodyWorks" presents six major areas: warm-up, arms, legs, on the tummy, massage and family play. With names like "fun on the pillow" and "dual arm raises," the exercises are simple and nicely demonstrated. But unless the exerciser is quite small, they're not very challenging.

Two disappointments are the massage section, which is five minutes of watching someone rub lotion on a baby, and the family play section, which is five minutes of watching folks sit around doing sit-ups with an infant.

Without the "giving your baby a headstart" hype, these programs would be enjoyable. The emphasis should be taken off peak performance and put back on fun.