I'm a square. I'm a stable and predictable exerciser, and I thrive on routine. This makes me reliable and so set in my regimen that I'm likely to never see progressive results. I keep doing the same things (running and walking), and because of this, I might just live my life at a fitness plateau. There's a fix for this, says Linda Shelton, a fitness expert who spoke last weekend at the American College of Sports Medicine's Health and Fitness Summit in Atlanta. There's a fix, in fact, for the pitfalls of all five fitness personality types Shelton has identified.

Squares. If you're a square, you cling to the pattern of your workout routine. "Instead, a square should try to take baby steps toward sprinkling in new activities weekly that switch up their routines while still giving them the familiarity of the old program," says Shelton.

Rectangles. These folks also like order and routine, but they are more flexible. Rectangles should join hiking or running groups, or take group fitness classes instead of exercising alone, Shelton advises.

Triangles. The most competitive of the personality types, triangles are task-oriented, and they thrive on repetition -- this helps them monitor their progress and celebrate their successes. Shelton says triangles need to train with an event or goal in mind, like a mini-triathlon or half-marathon. They should also work out with an equally competitive partner.

Circles. Circles, the most common type, are social butterflies, who rarely work out alone. "Circles sometimes talk the entire way through a workout; they're not really there for exercise so much as camaraderie," says Shelton. "They need a nurturing trainer who will motivate them, yet not push too hard, or to exercise in a group setting."

Squigglies. Squigglies are the most outgoing and least-structured fitness personality. They hate routine, and if they aren't enjoying what they're doing, they quit. They need varied workouts, says Shelton, so they can maintain an interest in exercise.

Did you know you have a fitness personality? Shelton says everyone has one. She also reports that most people fail to stick with an exercise regimen because they are not exercising according to their personality. Knowing your fitness personality, she says, is key. When you know what suits you, you're more likely to enjoy exercise and stick with it.

Think about it and tell us: What's your fitness personality?