If you're skipping your workout way too often, you're not necessarily lazy - you just might not have the right head for it. In a time when kids and curious weekend warriors are taking DNA tests to find their perfect sport, trainers are customizing workouts to their clients' psychology. According to Linda Shelton, a trainer's trainer in Los Angeles who developed this personality-centric program, everybody is one of five shapes, each of whom require a special workout and teaching style.

If you: are dependable and predictable; a stick in the mud

You're probably an: "L" for Linear, Literal

You respond best to: a consistent non-competitive regimen; workouts alone; a trainer that provides detail-oriented instruction and gives you your space

If you: are laid back and a social butterfly

You're probably a: "C" for Chatty Cathy

You respond best to: Group exercise classes; or activities, like a run-walk with friends, that offer rewards upon reaching a goal

If you are: fiercely competitive and results-oriented; a thrill-seeker

You're probably an: "A" for Ambitious, Accomplished

Your respond best to: goal-driven training, such as preparing for a 5K; keeping a log; training with someone fitter than you

If you: like consensus-building and are broad-minded

You're probably a: "D" for Diverse, Discerning

You respond best to: group classes or non-competitive sports outings, such as hiking, which you help organize and design

If you: are creative and spontaneous and get bored easily

You're probably an: "S" for Spontaneous, Stimulated

You respond best to: constantly changing, think-outside-the-box workouts (circus training one day, boot camp the next)

What Do You Think?