Drills For The Core

One-legged side Bends
"Carrying a heavy load, like a pack for an overnight snowshoeing trip," says Musnick, "is going to challenge your balance even on level ground." Standing on one foot facing a wall eight to 12 inches away, hold a three- to five-pound medicine ball with both hands over your head. Bend your trunk to the right and then return to the center. Do the same toward the leftand when that gets easy, try leaning forward and touching the wall with the ball at ten, 12, and two o'clock. Easy? Speed up the movements. No problem? Try it with closed eyes. Do two to three sets of 15.

Supine Crunch on Balance Ball
To develop important stabilizer musclesthe obliques and transversustake your crunches to the wonderful, wobbly world of the balance ball. Sitting on the ball, walk your feet out until your weight rests on your shoulders or upper back and your hips are in the air. Raise your torso and perform a crunch as you would on flat ground. Do two to three sets of 12 to 20 reps.

Medicine-Ball Toss on Balance Ball
"A lot of injuries from kayaking occur to the rotator cuff," says Musnick. The same holds for cycling. Develop a seated ability to keep your center of gravity. Sit on a balance ball facing a partner and play catch with a medicine ball. Throw two-handed to alternate sides, arms out. Keep a minimum of weight on your toes. Do two sets of 30 to 45 seconds.

One-Legged Overhead Tubing Twist
"We have three planes of motion," says Musnick. "Front-to-back, side-to-side, and rotational. People should think about doing exercises in each of these." Or one that does all three, like this: Secure resistance tubing with handles to a door frame or other anchor about head height. (You can also use weighted cables at the gym.) Hold a handle in each hand and position yourself to create tension on the cords. Balance on one leg, place your arms over your head, and quickly push one handle forward while the other moves back. Focus on rotating your trunk, rather than pulling your arms, to make the twisting motions. Do one to two sets of 30 seconds on each leg.