They started with frog jumps, moved on to bear crawls, and finished up with a weight-lifting exercise that required an “angry gorilla chest.”

The athletic contest with a bit of a zoo theme was Seaside CrossFit’s first kids’ competition, held Friday evening at the Kendrick Road gym. Thirty kids, ages 6-12, from CrossFit Cynergy in Hanson, CrossFit 508 in Plainville and Seaside battled it out through three “WODs” (workouts of the day) designed for kids’ fitness and enjoyment.

The enjoyment was obvious. While some of the older competitors wore the game faces of adult CrossFit competitors, most of the athletes went through their paces with smiles on their faces. Several spent their time between heats busting out dance moves, demonstrating cartwheels and staging an informal competition jumping off the gym’s 20-inch boxes.

CrossFit is a fast-growing exercise program designed to promote total fitness by incorporating elements of calisthenics, weightlifting, aerobic training, gymnastics and more into short, intense, varied workouts.

Seaside CrossFit was founded by Jenn and Matt Christopher of Marion in 2011 in their Marion garage. After rapidly outgrowing expanded quarters in Marion, the “box” -- as a CrossFit gym is known -- moved to the Wareham industrial park in 2013. With the move came the expansion to offering kids’ CrossFit classes.

Similar to adult CrossFit, the kids’ classes feature a range of exercises, several of which were on display Friday. Weightlifting was hefting a 15-pound “training bar” overhead for the older kids, a length of lightweight plastic pipe for the younger ones. Then there was the bear crawl (using arms and straight legs) around orange traffic cones, the CrossFit signature “burpee” (a combination of pushup and jump) and the frog jumps for distance.

Adult Seaside athletes served as “judges” – a role that appeared to be more about keeping order and providing encouragement than ruling whether a particular exercise was done precisely correctly.

Standing on the podium at the end of the evening were Seasiders Noah Thornell of Mattapoisett (second place, 6-7-year-old boys), Caroline Houdelette of Marion (first place, 6-7-year-old girls), Hailey Lawrence of Marion (second place, 6-7-year-old girls), Logan Leblanc of Marion (first place, 8-9-year-old boys), Alec Arsenault of Mattapoisett (second place, 8-9-year-old boys), Ava Sepulveda of Marion (first place, 8-9-year-old girls), Elizabeth Houdelette of Marion (third place, 8-9-year-old girls), Liam Houck of Marion (first place, 10-12-year-old boys) and Emma Thornell of Mattapoisett (third place, 10-12-year-old girls).