If you're an exercise enthusiast who keeps up with all the latest trends, you've probably heard about CrossFit and its WOD, RXs and AMRAPs. • Beyond the shorthand lingo, CrossFit is known for delivering faithful followers trimmer, firmer, stronger bodies prepared for demands that range from carrying groceries to carrying a limp body away from enemy fire. • Since its beginnings in California more than 20 years ago, the CrossFit craze has spread to more than 9,000 locations worldwide with a loyal following among mostly young and middle-aged adults, many of them in the military or first responders including police officers, firefighters and paramedics. • Now CrossFit is becoming popular with a new crowd: children, even those in preschool. Although much less intense than the adult version, it promises to prepare kids for competitive sports and vigorous pursuits like mountain climbing. • At age 9, Luke Bernstein is convinced that CrossFit has improved his baseball game. • "I'm a pitcher and it has really strengthened my arm. I can hit better and throw better," the St. Petersburg boy said. • For the Bernsteins, CrossFit is a family affair. Luke expects to graduate to grownup CrossFit before too much longer — after all, his 13-year-old brother moved up this year to the adult program, where he works out beside their dad at CrossFit StPete, a box that offers programs for adults and kids.
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So how does CrossFit work? Let's start with a few basic terms:
• You call the place where you work out a ''box,'' not a gym.
• Your routine is known as the WOD, or workout of the day. Some are "hero workouts" dedicated to soldiers, firefighters and police officers killed in the line of duty.
• If you see AMRAP next to an exercise it means you are to do as many rounds (or repetitions) as possible.
• RX means to perform an exercise exactly as written.
In CrossFit, all members of a particular box do the same basic WOD, with the intensity scaled to their abilities, but the WOD changes daily. Members are expected to support and encourage each other.
Workouts may feature bursts of cardio, core and strength training, stretching, jumping, climbing and maybe even a little gymnastics, all emphasizing proper form and safety. The time it takes you to complete the WOD is usually posted on the wall or a website to add a spirit of friendly competition to the experience.
Kids get a WOD of their own. While most boxes don't have formal programs for kids (check crossfit.com and call ahead to find one near you), CrossFit StPete offers twice-weekly sessions scaled for young bodies. For instance, children may do 10 situps, whereas adults might be instructed to do as many as they can for a minute or two.
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At a recent session at CrossFit StPete, the children's activities, which seemed more like games than exercises, were focused on improving strength, balance, coordination, concentration, problem-solving abilities and self-confidence.
CrossFit StPete, which is preparing to move to a larger facility at 4001 35th St. N, has offered CrossFit Kids since 2009, making it one of the longest-running children's CrossFit programs in Florida. Meghan Dorman, 32, a certified CrossFit trainer, took a special course to become certified to teach CrossFit Kids.
On a recent Thursday afternoon, 11 children, ages 5 to 12, gathered on the red cushioned floor mats. A handful of adults — some, parents of the children — worked out on the other side of the box (a converted warehouse) with trainers.
A few family members, mostly grandparents, watched from a nearby picnic table.
Coach Meghan, as the kids call her, warmed up her charges with squats, situps and "Supermans" before taking them outside to start the WOD. Once back inside on the mats, it was time for a formal lesson on how to do a handstand from a squatting position. Some kids tumbled down right away, while others got close to pushing their feet toward the ceiling.
As Dorman helped one youngster find his balance, another child decided to play coach for a young friend.
In 45 minutes they worked on strengthening legs, arms, hands and core. They ran sprints, practiced broad jumping, worked on coordination and balance, and negotiated an obstacle course. They tried the handstand over and over. They all pushed themselves to be a little bit faster, jump a little farther.
Jennifer Lockwood, 33, has been doing CrossFit with her husband for about a year and a half, and her lean figure shows it. She likes the supportive atmosphere.
"People who are finished with their workout will gather round and stay late to encourage you until you're finished," said the Pinellas Park woman, whose three boys are all in CrossFit Kids.
Like the other kids at a recent session, Ethan, 10, Ephram, 8, and Evan, 5, all say the classes are fun, but rope climbing is their favorite activity. Ethan and Ephram are doing better in sports since starting CrossFit, their mom says.
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Bill Campbell, an associate professor of exercise science at the University of South Florida, said the CrossFit Kids exercises all sound good because they build strength, bone density, balance and coordination.
But his advice for parents would be to check out how well trained their child's coach is. He thinks instructors, especially those who work with children, should have a college degree in exercise science in addition to certification from a major organization such as the National Strength and Conditioning Association.
"Research demonstrates that the likelihood of injury drops when people who are credentialed in the field run the programs," Campbell said. "There are plenty of instructors who do a great job, but there may be some who have no business instructing adults, let alone children."
Whether you take your kids to a CrossFit box or let them loose at the local playground, Campbell is a fan of combining fun and fitness. "Anywhere they can run, jump, climb, crawl. I love that," he said.
Irene Maher can be reached at email@example.com.