Three exercises from "Core Advantage" recommended by Allison Westfahl that, performed together, offer a well-rounded core workout.
Time Trial Final Sprint. This exercise will help you extract every ounce of strength and stamina from your core by teaching your core to hold still while your arms are sliding back and forth. Grab two small hand towels for this exercise. Fold the towels a few times, and place one under each elbow while you are in a plank hold. Without moving your lower body or rocking your hips, slowly slide your right forearm forward 3 inches while pulling your left forearm back 3 inches. Continue to slide your forearms back and forth, being sure to keep the rest of the body as still as possible. Hold this position for as long as you desire. Remember to breathe.
Competition Check. This exercise improves balance, stabilization and intramuscular coordination of core muscles; it also decreases the risk of crashing when looking over your shoulder on your bike. Start in a push-up position with shoulders directly over your hands and your tailbone slightly tucked. Keeping your hips low, pick your right foot up off the ground and start to bring your right knee in toward your right elbow while you simultaneously turn your head to look at your knee. This should create a crunch on the right side of your body. Return to starting position and repeat on the right side for the
Musette. This exercise improves rotational strength and stabilization with an emphasis on the internal obliques. Start in a seated position, your knees bent and heels lightly touching the ground. Lift your chest and feet to knee height, pull your shoulder blades down and together and keep your neck neutral. Make a fist with your left hand pushing into your right palm, keeping both hands in the center of your chest and 6 inches away from your body. With your legs held steady, twist your upper body (still pushing that left fist into the right palm) as far to the right as possible. When you reach your twisting limit, push your left fist into your right hand with as much force as possible for 15 seconds. Come to center and switch sides, this time making a fist with your right hand and pushing it into your left palm.