But when Liam picks up two five-pound dumbbells and waves them around like stuffed animals, or does rapid-fire sit-ups, it becomes abundantly clear that he has an extraordinary gift.
In short, he's strong as a bull.
"A lot of the TV stations wanted to do the 'World's Strongest Boy' type of stories," Dana Hoekstra said. "They weren't interested in the science behind his condition ... and I wasn't going to put him on some kind of freak show."Liam's amazing strength, the result of a rare genetic condition called myostatin-related muscle hypertrophy, has made him something of a global media darling.
"A lot of the TV stations wanted to do the 'World's Strongest Boy' type of stories," Dana Hoekstra said. "They weren't interested in the science behind his condition ... and I wasn't going to put him on some kind of freak show."
Myostatin-related muscle hypertrophy, or muscle enlargement, is an extremely rare genetic condition. It promotes above-average growth of the skeletal muscles without harming the heart or causing any other negative side effects.
Scientists discovered the condition in the 1990s in Belgian Blue cattle, an unusually muscular breed. The first human case was documented in 2000, in a German boy, but wasn't reported in medical literature until 2004.
Experts have said the condition is so rare in humans, scientists don't know how many people have it.
For Liam, the result was having 40 percent more muscle mass than other children his age. He is terrifically strong, quick as a rabbit, has the metabolism of a gerbil and almost no body fat.
His amazing strength and the rarity of his condition has generated international media attention. The Chronicle's 2005 article was published in newspapers around the world and distributed widely on the Internet -- a recent Google search for Liam Hoekstra produced 14,800 hits.
His mother, Dana Hoekstra, said she's not surprised by all the media interest.
"Liam is everything a lot of us want to be -- all muscle, no body fat and he gets to eat whatever he wants," she said.
After The Chronicle featured Liam in a 2005 article, he has been the subject of a Japanese television documentary on rare medical conditions. A British documentary crew is coming in February to film Liam in action and the National Geographic Channel is considering doing a segment on him as well.
"All the Grand Rapids TV stations wanted to do a story on Liam, we've been contacted by three national stations in the U.S. and programs in Japan, England, Belgium and Argentina," said his mother, Dana Hoekstra. "We've been contacted by Entertainment Tonight, Good Morning America and the Maury Povich show."
Dana Hoekstra and her husband, Neil, have turned away at least a dozen television news crews that wanted to do stories on their boy wonder.
The Discovery Channel sent a producer to meet with the Hoekstras but decided not to do a documentary on Liam because his tremendous strength was not evident to the naked eye, Dana Hoekstra said.
Liam's strength is not evident until he participates in an activity that requires raw power, such as sit-ups or chin-ups.
"He's amazing at doing sit-ups because his abdominal muscles are so strong," said his mother, who is a physician's assistant. "When he does sit-ups you can see how he is stronger than other kids his age."
The Hoekstras put Liam in a gymnastics class earlier this year to provide an outlet for his abundant energy.
The 30-pound boy thrives in strength-related activities. But Liam struggles with his balance and is less flexible than other children his age, said Phil Bishop, the head coach at Cassell Gymnastics and Dance in Norton Shores.
"He's very strong -- I think he'll eventually be a great athlete," said Bishop, who works with Liam once a week.
Bishop pointed out the major difference between Liam and other three-year-olds in his class as the children did chin-ups. Two other children in the class struggled to pull their chins up to the bar; Liam performed the task with ease.
With a little assistance from Bishop, Liam then hoisted his torso above the bar, locked his elbows and held his position.
"That's where you see the difference; he has tremendous upper body strength," Bishop said.
Dana Hoekstra said the parents of other children at the preschool Liam attends initially feared the boy would be a danger to other kids.
"The other parents asked me if Liam would hurt their kids," Dana Hoekstra said. "I told them he doesn't know his own strength."
Liam is slightly smaller than average for his age but is projected to reach a height of around five-feet, nine-inches tall by the time he's done growing. His mother said his muscle condition will become evident when Liam begins adding weight and lifting weights in his teen years.
"When he starts working out with weights, he will build muscle much faster than other kids," his mother said. "Then it might look like he's on steroids."
The Hoekstras, who are devoted University of Michigan fans, dream of their son playing football someday for the Wolverines.
They were unaware of Liam's condition when they adopted him at birth. They believe he inherited myostatin-related muscle hypertrophy from his biological father, who reportedly possessed tremendous strength.
Liam's condition is more than a medical anomaly.
Scientists are studying other people with myostatin-related muscle hypertrophy in an effort to understand the mysteries of muscle growth and deterioration. Research on adults who share Liam's condition could lead to new treatments for debilitating ailments, such as muscular dystrophy and osteoporosis.
Experts have said the ability to manipulate myostatin in the human body could also become a hot commodity among athletes looking to gain an edge, perhaps illegally, on the competition.
Dana Hoekstra said she is eager to see how Liam develops. "Once he figures out his strength, it should be quite amazing."
by Jeff Alexander | The Muskegon Chronicle
|Video: Liam Hoekstra leaves a strong impression|