Size 2 to 4
Petites should look for clothes that are cut a certain way and don't look like they're hanging on them. People may not really think about it, but jackets and shorts can even be cut too long. And if the short looks too long, then it's just not going to look right.
A streamlined Asics jacket is shorter in length and hits at a good place on your body. It also folds up into a fanny pack so you can carry it with you wherever you go.
The FitnessFit shorts are lycra cotton and are the perfect cut for smaller women. They are a shorter short, so you won't get the long, baggy look and they also have an adjustable drawstring. If you're having a day where you need then a little looser, you can size them to fit.
The Lululemon Athletica Pirouette sports bra is designed for a women with smaller chests and also specifically for a low-impact workout. It's lined but sports bras have different levels of support, and this is a lower level.
The Pump Energy shoe by Reebok is adjustable. If your feet are narrow, pump it up and make it really cushioned. If you're wider, you can let the air out so it's sized to fit you. While you're wearing it, if you think you want it tighter, just adjust it as needed.
A nice accessory is a pink MP3 player by Creative. You can download up to 1,000 songs and videos, including workout videos, so they're easy to take along with you.
Size 6 to 8
The Adidas TechFit Tank top is designed with special technology to keep your muscles in place while you're working out, with the goal of helping them from becoming fatigued. The front of the tank has bonding strips that provide a flattering fit.
The pants by KOS USA have a V-shaped waistband, which elongates your torso and makes you look really long and lean. A lot of people don't like wearing shorts and these are a nice option.
The CW-X Firm Support Bra is designed for a high-impact workout like running, so it holds you in so you don't get any bounce.
The Ryka running shoes are designed for people with high arches. If you have that problem, you need support in a shoe, especially when you're exercising.
The Adidas Performance Adistar Curve Watch is designed to give you easy access to your distance and time when you're running.
Size 8 to 10
A sporty tank has a built-in bra, and the knot and cutout in back is a great fashion detail. The color is terrific, too; generally a light color on top and black on the bottom is very slimming. The cotton spandex pants have a bootleg cut for a flattering fit. They also contain a Coolmax insert to help wick moisture away.
The Saucony Omni sneaker stabilizes and straightens your foot when you run, and the shock absorber heel provides cushioning. The liner is antimicrobial and keeps moisture from building up so your feet stay dry.
And you may not ever really think about your water bottle, but the Amphipod Hydra form water bottle has a zippered section for storing your stuff (keys, ID). It's designed in the shape of a handle so you can easily grip and hold it while you're running.
Size 10 to 12
A tank-top by Champion features a built-in underwire bra for extra support and comfort. It's for women who have bigger chests, because you're putting an enormous strain on the chest when you exercise, so you want to ensure that you're firmly in place. You could wear the tank alone, since it does have that support, but you wouldn't want to do a high-impact activity like running. It's great to wear alone for something like yoga.
The Goddess Sports Bra 2000 is helpful if you're big in the bust. It has a good fit and evenly distributes the weight. Also, the straps are individually adjustable, so you can really get it to fit the way it should.
The skort (a skirt with shorts underneath) is hugely popular right now, a big trend in workout clothes. It minimizes the hips and gives you a flattering fit, and even in the back it covers up anything you might be self-conscious about. And it's so cute, after the gym you can run errands, etc.
The Nike Air Zoom Haute+ and it works wirelessly with an iPod Nano. A special chip in the shoe top communicates with the Nano and tells you how many calories you're burning, how far you've gone, etc.
Sunglasses are a common accessory for anyone exercising outside; you should wear them to protect your eyes from UV rays. The Adidas Adilibria sunglasses have three settings so that they'll fit perfectly snug on your nose and you don't have to worry about them falling off.