The rising popularity of boutique fitness studios (think Pure Barre and Orange Theory) has us all itching to discover fresh and fun ways to work out . The problem though, is that boutique studios tend to charge a pretty penny. A single class can set you back more than 30 bucks; and many yoga studios have drop-in fees around $20. But you don't need to spend a fortune to score a great sweat sesh. Some of our favorite brands—from Lululemon to Nike—are offering free fitness classes in-stores and online, so you can breathe new life into your usual routine for no cost at all.

Lululemon Athletica

Since the company opened its first store in 1998, it has grown from a yoga-based brand to one that caters to all sorts of active pursuits. But in keeping with Lululemon's core mission, locations across the country offer complimentary in-store yoga classes. The stores partner with local studios that send in a certified instructor each week to teach an open-level class. And many locations collaborate with other types of fitness studios too, so they can offer additional classes. Some stores even facilitate a weekly run club.

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Sweaty Betty

Sweaty Betty's #GetFit4Free community initiative includes in-store classes in select locations, as well as online videos of classes, including boxing, HIIT, barre, even boutique classes like Barry's Bootcamp and Body by Simon—so you can do these super-intense workouts right in your living room, for free! Check out the offerings on Sweaty Betty's YouTube channel too.

Nike

What can't Nike do? In addition to providing us with some of our favorite high-performance gear, the brand also makes fitness accessible to anyone willing to put in the sweat. Most major cities across the country have a Nike+ Run Club, which offers a series of workouts aimed to help improve your running game, whether you're a newbie or a seasoned athlete. Expert coaches and pacers teach classes for speed training, long runs, HIIT, full-body workouts, and more. Be sure to also download the free app Nike+ Training Club to access workouts you can do anywhere.

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The North Face

If you gravitate toward more outdoorsy activities (say, hiking, climbing, or running) head to The North Face for their Mountain Athletics Training programs. The free sessions are held twice a week in Washington, D.C., Boston, Chicago, New York, and San Francisco at 6:30 p.m.—rain or shine. They are designed to get you closer to your goal, whether that's building endurance, becoming a stronger skier, or summiting a 14er.

R.E.I.

Much like The North Face, R.E.I. offers programs designed to facilitate your adventures in your activity of choice, from paddling and cycling to climbing and snow sports. You can search by location or activity to find free classes, outings, and events run by experts.

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Athleta

The brand's flagship location in New York City has a full schedule of free classes every day from 9 a.m. until the evening; and Athleta stores nationwide offer free classes—such as yoga, Core Fusion, and pilates—on weekends. Use the Athleta store locator to look up retailers and class schedules near you.

November Project

It's not a retail brand, but the November Project is an incredible resource for people looking to get fit and join a community—all for free. It is a worldwide movement that holds members accountable for sticking to their outdoor workouts (no matter the weather). Currently, there are 21 groups in the U.S. All you have to do is find the nearest one and show up! "We welcome everyone and anyone regardless of age or fitness level," the site explains. "Our members range from professional athletes and Olympians to recent couch potatoes that decided to do something about their fitness."

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Your local running store

Many local shops organize weekly group runs and cross-training workouts that you can attend at no cost. One of the bigger networks of running stores, the Running Specialty Group, offers various events. Check to see if there is a store in your area and stop by to find out what they're up to.