OK, you have less than a week until Halloween, and you still don't have a costume. Don't worry -- for a fit beauty like you, looking festive and fabulous is a piece of (low-fat, sugar-free) cake!

Seek your inner athlete (doesn't matter if you actually play the sport) and put together a fun, fitness-focused costume using the suggestions below.

Marathon Runner
What You Need: Short little shorts, knee socks, a headband, tennis shoes and an old race tee (ask friends and family, or check your local Goodwill).
Bonus: A Walkman (an iPod will do, but I think the old school Walkman is a lot more fun) and a water bottle (fill it with whatever you like!).

Yoga Instructor
What You Need: Yoga pants (stuffed with newspaper) and a tank, socks (also stuffed), a box to wear around your waist. Cover the box in a fabric or paint that looks like a yoga mat and cut a hole in the middle for your waist. Sew (or pin) your stuffed yoga pants to the back of your top, then bend the legs up over your shoulders so you look like you're in some crazy-flexible pose. Pin or sew the socks to the bottom of the pants to give yourself feet.
Bonus: Calming yoga music coming from your phone or a portable stereo.

Aerobics Instructor
What You Need: Hey, the '80s are back, right? Go with Jazzercise-worthy workout clothes -- leotards, baggy tees, leggings, leg warmers, whatever floats your boat.
Bonus: Big bangs and a ponytail secured by multiple scrunchies.

Boxer
What You Need: Silky shorts, a little tank or sports bra, and an official looking hoodie (ideally with your name or nickname on the back -- get creative!). Also, use your regular black and purple eyeshadow to create a black eye.
Bonus: If you don't own boxing gloves, hand wraps are cheap and give a similar effect. Make sure to threaten to punch out anyone who cuts in front of you at the punch bowl!

Basketball Player
What You Need: Long, baggy shorts or tear-away warm-up pants, a jersey or warm-up shirt (ideally with a name and number on the back), tennis shoes.
Bonus: Rent some painters stilts (practice ahead of time) and wear your warm-up pants over them so you seem to be seven feet tall. A friend of mine did this a few years back, and it's still one of my favorite costumes ever!

What's scarier than finding a costume at the last minute? Halloween candy to someone on a diet!