Think of that first canoe paddle of the year: Your arms and shoulders often start to ache long before you tire of the scenery. Right now is your last chance to ensure that you won’t be sore come your first endeavors of summer. The key to countervailing gratuitous pain lies not only in getting your arms ready, says Traverse City personal trainer Doug Petersen, but also in developing a strong core. The core – think torso – is the body’s center of power, made up of the abdominal muscles and the lower back. Since your arms and legs are both anchored to the core, this part of the body is really the origin of movement. Having a strong core musculature means you’ll be able to stabilize the spine and more effectively move the body without injury.

"When your core is weak, you compensate by using only upper body strength," Petersen says. If you can depend on your core as well as your arms he says, "You’ll be thinking less about lower back pain or sore shoulders." In the end, having upper body strength is important, but a strong abdomen and lower back will let you stay out paddling for hours longer. Likewise with water-skiing, windsurfing, and sailing – all rely on the power of strong arms, but with a strong core you will enjoy improved balance and overall coordination. Even runners can benefit from core strength: it will be easier to hold proper running form – your arm swing, gait and stride – longer.

To get a strong core, you need to engage your trunk in movement and build muscle in the abdomen and lower back. The most empowering news is that if you begin training now, you will have the strength when – and where – it matters.

Here’s a simple routine to get you started on a stronger core:

Push Ups work the chest, shoulders, triceps, upper and lower back.

Traditional: Keep your arms perpendicular to your body and your back perfectly flat. Concentrate on drawing the belly button to the spine, and breathe throughout the push up. Keep your face aimed at the floor.

Modified: Lower your knees and cross your ankles. Keep a flat back and breathe throughout the push up. Do 3 sets of 15 to 20 with a minute rest between.

Crunches work the rectus abdominis and obliques. In order to strengthen your core, you can do a multitude of abdominal exercises. To get started, Petersen recommends the crunch.

The classic: Cross arms on your chest, lift shoulders and upper back straight up off floor without bending at the hip. Do 2 sets of 20 to begin.

Back DipS work triceps, chest and shoulders. A great exercise, though not recommended for those with a pre-existing shoulder problem.

Dip it: In a stable chair, begin with your thumbs under your rear and slide off the chair. With your feet straight ahead, dip down close to the chair, keeping the length of the arm from the shoulder to the elbow parallel to the ground. Do 2 sets of 10.

Emily Betz Tyra is associate editor at Traverse, Northern Michigan’s

Note: This article was first published in March 2002 and was updated for the web February 2008.