They're not only losing power and speed, but beating themselves up needlessly.The two key moves to effective carving (whether to carry more speed across the bottom of a halfpipe or to arc big turns across the hill) are punching the gas and stomping the breaks.
You need to implement these moves from the ground up, which means taking all that arm-waving and torso-twisting out of the equation. Think of a tightrope walker holding a balance pole: Keep your upper body quiet and let the movement start in your feet, ankles, and knees.
Starting with your toe-side turn, rock onto the balls of your feet. As soon as you feel that edge engage, drive toward the edge with your ankles and knees as if you were pressing down on a huge gas pedal with both feet. Don't wait; floor it right away. In racing we say, "Get it done above the gate. It means you should load the board at the top of the turn, and then ride the sidecut through—and enjoy. At the end of your toe-side turn, shift your weight forward from the tail of your board. Lift your toes toward your face and grind on your heels like you're slamming on the brakes. As you pressure your heels, sink into the turn, dropping down into a squat position so you can use your quads as shock absorbers. Keep your upper body still and upright. Like the toe-side turn, pressuring that edge early will set you up and let you ride through the belly of the turn with maximum power and ease. Once you feel the power, you'll be hooked.
Age: 31 Height: 6 feet 3 inches Weight: 220 pounds Home Area: Aspen/Snowmass, CO Accomplishments: 2002 Olympic bronze medalist, 1997 U.S. Open Champion, six-time U.S. National Snowboarding Champion. Worst Learning Experience: "Twenty years ago, in my duct tape—fortified moon boots, I took my wooden Burton Performer (which had no edges) onto the hardpack at Mount Bachelor, Oregon. I saw stars after the first crash—and after the second one, too. I can't remember if I saw them on the 10 crashes after that. I guess I was concussed. I was lobotomized by the time I figured out that there was just no way to ride without edges. I've never forgotten how important good edging is to riding well.