You may be under the impression that you need to join a gym if you want to take exercise seriously. Although gyms offer a wide variety of equipment as well as personal trainers to assist you, don't be discouraged if you can't afford a gym membership. Plenty of low-cost alternatives are available to help you get fit.

If you're just getting started and are looking for real fitness bargains, here are some low-cost exercise products you can buy for the home or take with you when you travel:

• Dumbbells. Dumbbells are small, hand-held weights that you can use to strengthen your upper body. They come in a variety of sizes, from about 2 pounds all the way up to 50 pounds.
• Jump-ropes. They're lightweight and easy to pack, so you can take this cardiovascular workout on the road.
• Resistance tubing and bands. Used for strength training, these lightweight, portable bands come in varying degrees of resistance, depending on your fitness level. You can also change the level of resistance by changing the way you hold the band. You can do a variety of upper and lower body exercises with resistance equipment.
• Exercise videos. Recreate the feel of a health club aerobics class in your own living room. Many videos are good for improving strength and flexibility, too. Before buying a tape, check the instructor's credentials. If it's a celebrity's tape, do certified fitness instructors serve as advisors to ensure that the workout is safe and effective? Pick a tape that matches your current fitness level so that you don't get discouraged by exercises that are too hard or too easy. If you can, borrow the video from your library first to see if you like it.

If money is particularly tight, use ordinary household items rather than purchasing equipment you can't afford:

• Fill empty milk, water or dishwashing-detergent bottles with water or sand and secure the top with duct tape to create an inexpensive set of adjustable weights. By adding more water or sand to the jugs, you can adjust the weights as your fitness level changes. Use your household scale to check the weight. These weights are good for upper body exercises and as added resistance for lower body workouts.
• Canned goods come in a variety of sizes and are easy to hold in your hand as weights. You can also take a pair of tube socks and put an 8-ounce can in each. Tie the socks together, creating a 1-pound bag that you can use as an ankle or hand weight.
• Bags of cereal, potatoes and frozen peas come in sizes from one to 10 pounds. You can use them for a variety of exercises, including chest presses, calf and shoulder raises, leg extensions, and squats or lunges.

If you feel the need for a specific piece of equipment or a class, don’t go with the first one you see. Shop around.

• Think twice about your needs. If you want to do step training — an aerobic exercise resembling stair climbing — do you have to have the $1,500 home stair stepper? Or would a fitness step or low, sturdy step stool and some step aerobic videos do the trick at a fraction of the cost?
• Buy used equipment. Look in your local Yellow Pages for stores that specialize in used sporting goods and exercise equipment. Check your local newspapers and office, store or college-campus bulletin boards, and you'll frequently find barely used exercise equipment for sale. The same goes for online auctions. A word of caution about buying online, though — make sure the cost of shipping won't put the item out of your budget.
• Check out your local recreation department. They frequently offer discounted fitness classes to local residents. If you live in a college town, see if their fitness center is available to members of the community. It often is, at a price much more reasonable than a privately owned gym. If you're an alumnus of the school, you may qualify for an even better rate.
• Share costs with a friend. Trade exercise videos with a friend so that neither of you gets bored doing the same workout over and over again. Another option: Some personal trainers will let you split the cost of a session with a friend or two.

You don't necessarily need special equipment for a cardiovascular workout. With a little foresight, activities you take for granted can become part of your exercise routine.

• Step it up. Walking is a free activity you can do almost anytime. If the weather is bad, walk briskly around the mall or even a local museum. Take the stairs instead of the elevator. Sneak in extra steps whenever you can by parking farther away from stores or work. One investment you might want to make, though, is in a good pair of walking shoes.
• Play with your children. If you have children, you have willing exercise partners. Don't just watch them play. Join them for a game of tag or kickball. Or walk them to the park rather than driving.
• Don't hire extra help. Shovel the snow yourself in the winter and don't hire anyone to mow the lawn in the summer. You'll get some exercise and save the cost of having someone else do these chores.

Just because something is "natural," affordable or easy doesn't mean it works or is safe. Some fitness products aren't worth buying, no matter how low the price. Save your cash and avoid:

• Herbal supplements — or other products — that claim fitness benefits overnight.
• Trendy exercisers that focus on one body part, such as abs or thighs. There's no such thing as spot reducing.
• Thigh creams and other products that promise to take inches off without diet and exercise.

Remember, exercise can do you a world of good. But it won't if you focus more on the trappings than the actual physical activity. Don't get caught up in memberships or purchases you can't afford. Concentrate on your fitness goals, and act on them through means consistent with your purse strings.