Most surfers are content to ride down the face of a wave, but that isn’t enough for John Florence. He performs back flips and twists.  The surfer from Oahu’s North Shore, known as “John John,” was on a bodyboard at age 3. At 13, he became the youngest surfer to compete at the Vans Triple Crown of Surfing, a series of three competitions in Hawaii. At 19, he won the 2013 competition. This year’s competition began Nov. 12 and continues through Dec. 20. Mr. Florence’s aerial maneuvers, many of which reference skateboarding tricks, are often described as the future of surfing.  Just as trail runners and football players worry about coming down on an ankle wrong, so do surfers. “When you’re doing airs on a surfboard you come down on your board and the water pressure from the wave against your ankle can lead to some serious tweaks,” Mr. Florence says. He suffered two injuries filming his new movie, “View From a Blue Moon,” which premiered in eight cities world-wide Nov. 11 and will be released on DVD/Blue Ray, iTunes and additional digital platforms, Dec. 1.  The film, shot in Hawaii, Tahiti, South Africa, Western Australia and Brazil, took nearly three years to finish. On the first trip for filming, Mr. Florence landed an aerial move awkwardly and twisted his left ankle, tearing ligaments. He was out of the water for three months.  Despite going stir-crazy from being on land so long, Mr. Florence says rehabbing his injuries has made him a stronger surfer. Two days after the first injury, Mr. Florence flew to Costa Mesa, Calif., to start working with a physical therapist, Mark Kozuki, owner of Elite Performance Physical Therapy.  “I thought I was strong,” Mr. Florence says, “but during the rehab, Mark assessed my overall core strength and stability, and we found a lot of weak links.”  Before the injuries, Mr. Florence’s workout entailed surfing every day, but not much formal training and stretching. Mr. Florence has his sights on winning a World Surfing League Championship title. Currently, he is ranked 15th on the world tour.  Mr. Kozuki says a lot of rotational athletes—surfers, golfers, tennis players—tend to twist one particular way, which leads to muscle imbalances and overuse injuries. Surfers have either the left or right foot forward on the board and due to the position of their feet, when they face forward, their body is relatively twisted in the same direction as their stance.  Mr. Kozuki uses Redcord, a suspension exercise system similar to a TRX that was developed in Norway to help detect musculoskeletal imbalances. The system uses body weight for resistance. Mr. Kozuki has Mr. Florence perform a side plank, with his hip and legs suspended in the Redcord straps. “Sometimes in side plank, the glute muscle on the outer edge of the hip, the glute medius, is prone to being weak,” explains Mr. Kozuki. “Performing the pose while suspended isolates the glute medius and stimulates the muscle.”  Mr. Florence’s other core strengthening exercises include holding a bridge pose until his muscles start shaking, then lowering slowly back down and repeating. He performs squats with both legs and with one leg on Dyna Discs, which are circular inflated pads that create an unstable surface. He then balances on the Dyna Discs while Mr. Kozuki throws a medicine ball back and forth with him.  Mr. Kozuki said many exercises focus on “deep core” muscles. Mr. Florence will lie on his back with his knees bent and bring one leg up to tabletop position and then slowly lower it down to the ground, then bring the other leg up to tabletop position and back down. Then he’ll bring both legs up to tabletop position and back down to the ground. The idea is to isolate the core muscles so they do the work, not the lower back.  Mr. Florence says he has always avoided fast food, candy and soda. On the road, he seeks out home-cooked meals, rather than dining in restaurants. When he’s surfing, he starts his day with a small bowl of oatmeal. When he’s out of the water, he’ll have eggs with avocado, spinach and kale. He snacks throughout the day on trail mix and fruit and he eats an early dinner, often pasta with chicken and vegetables.  Mr. Florence owns, by his estimate, close to 90 surfboards of all shapes and sizes. He says he gets the majority of his gear from sponsors. He uses a Tiger Tail massage roller when he travels. The Roadster model retails for $27.95  “I pick a couple of songs, and I’ll listen to them throughout an entire competition,” Mr. Florence says. “My music taste changes drastically, but the core of what I listen to is Pink Floyd, Led Zeppelin and Black Sabbath.”  Write to Jen Murphy at workout@wsj.com
‘John John’ Florence, who has completed his film ‘View From a Blue Moon’ was sidelined by ankle injury. He began a physical-therapy regimen that not only repaired damage but aimed to prevent future harm.