"What's cool about these sites is if you don't live in a city and have access to good classes, these give access to top instructors," Bergen says.
Use free smartphone apps • There are many apps designed to help you get in shape. Bergen recommends apps including Tabata Trainer, a $1.99 interval training app focused on high intensity short bursts of exercise; Yog, a free app that helps you plan a run with anyone anywhere in the world in real time; and Nike Training Club's free app that features 100 strength workouts. Prevention magazine also has an app for the iPad called Flat-Belly Express for $2.99.
Check stores, parks departments and local recreation centers for inexpensive classes • Stores such as Lululemon, Reebok and Nike stores often offer free yoga and other classes. Senior programs at the YMCA or YWCA can also be good options. And state and national parks often offer exercise classes. "There are tremendous facilities all over the country," says Dr. Michael Joyner, an exercise researcher at the Mayo Clinic in Rochester, Minn.
Use outdoor gyms • In a growing trend around the country, some parks have outdoor fitness equipment. These so-called "adult playgrounds" can be accessed for free. The outdoor fitness equipment can include seats with bike pedals, chin-up bars, elliptical trainers, leg-press machines and other weather-proof equipment.
Check with your employer • Many companies are beefing up the incentives they offer employees to get in shape. Check with your employer to see if you can get gym membership discounts, free nutritionist visits, health coaching and other perks.
Walk or run • Walking is the easiest and cheapest workout there is. And it works, says Bergen, with Prevention magazine, who suggested signing up for a 5K to get motivation to stick with it.
"Walking is an amazing workout," Bergen says. "If you can do five to ten minutes two or three times a day, it can make a huge difference in your energy level."