Mirror, Mirror: Looking good at the gym, and later

Here we are, four days into the new year, and you're going hard on your resolutions: eating healthier, meditating, and, of course, working out. You dream of a tight core and doing the Broad Street Run.

How can fashion help you?

This month, apparel companies are introducing their spring collections of workout gear aimed at keeping us stylish before, during, and after we cycle.

To stay fit and focused, we need to hit the gym in between grocery shopping, picking up dry cleaning, and having cocktails. A simple T-shirt and yoga pants just won't do. So companies such as lululemon, Athleta, and Under Armour are producing collections that rival those on New York's runways.

Think bold-colored, body-hugging tanks layered under racer-back tops with empire waists or long-sleeved T's and pants - boot-cut and skinny versions - that mold to our bottoms better than a pair of Lucky Brand jeans.

"People want versatility in their clothing so they can go on with the rest of their activities," explained Tracy Byrnes, senior manager of innovation for Athleta, the women's athletic apparel brand owned by Gap Inc. that opened a specialty shop on Walnut Street late last summer.

Layering is key, Barnes said, as she pointed out Athleta's Contender skirt - a pair of running pants attached to a miniskirt that looks like a leggings/miniskirt combo.

The company also sells tights in denim hues that can double as jeggings.

Lauren Boggi, owner of the Philadelphia-based Lithe Method workout franchise, introduced Lithe Wear in the spring. Boggi created the 12-piece line of slightly goth workout wear that includes leather leggings (not exactly sure what it would feel like running in those) and lace capris.

"A lot of times I have meetings after work and if I'm teaching in my leather leggings all I have to do is wash my face, change my shoes into heels, and I look great," Boggi says. "Nobody can tell the difference."

To help you get your workout on at the dawn of 2012, we've compiled a list of must-have pieces from apparel manufacturers that will help you look fantastic as you work on being fit.

Athleta

Byrnes said the Athleta customer is all about CYA - covering your assets - after a workout. Hence the Contender skirt ($74). "It's a skirt with a capri and it's connected to one garment," Byrnes noted. It's not only cute, it features a removable water-resistant pouch, to keep cash dry, as well as mesh behind the knees for breathability and mobility. Out running early in the morning or at night before daylight savings time? This piece has reflective detailing. www.athleta.com

Under Armour

Known for keeping athletes toasty in cold weather, Under Armour introduced a new sports bra, the ArmourBra ($57.99). The bra is engineered to help athletes keep their assets together, and we can see the racer back under tanks and dresses. "We tailored the bra to each woman with a band and cup-size coding system," said Adrienne Lofton, Under Armour's senior director of women's marketing. "Each size features a gel back, closure system, and is constructed to be the ultimate in support and shape." www.underarmour.com

Lithe Wear

The Lithe Method is about keeping your body toned through dance and cheerleader moves. So it's no wonder that the clothing, by local designer Bela Shehu, is sleek. Leather leggings ($95) are wickable and tanks such as the Mojo Vented Top ($95) can be layered under sports bras or under blazers. www.lithemethod.com

lululemon athletica

The best thing about lululemon gear is that it allows for maximum movement. That's very important when you are running in below-freezing weather. Brrrr . . . . One of the first companies to blend lifestyle with workout needs, lululemon wrote the book on functional fashion. We love their red Scuba hoodie ($108) because it's both aerodynamic - check out the deep hood and high collar - and warm. Best feature: thumbholes to keep sleeves down and hands toasty. We also must mention the emergency hair tie on the zipper. A ponytail always trumps a bird's nest, especially on the track. www.lululemonathletica.com