The leg extension and leg curl work opposing sides of the upper thigh. Use them as part of a comprehensive lower body workout.

Once the darling new star of the gym, stair steppers may have lost ground to the newer design of elliptical machines. Still, you can usually find at least a couple of them gathering dust in the corner.

Sometimes, all you need is a pair of shoes, some open space and a little motivation to get a good workout. But it can be fun to try out cool new fitness tools and keep your gym bag fully stocked with odds and ends you might need before, during and after your workout.

Barbell squats are a highly effective exercise, as the movement "activates the body’s biggest muscles" and is the best overall exercise, according to kinesiology professor Stuart Phillips, Ph.D. Though effective, you may grow weary of performing the same exercise all of the time.

The Centers for Disease Control and Prevention reports that nearly one-third of the U.S. population is obese. Resistance training can be an important part of a balanced exercise plan, decreasing your risk of obesity and some factors, such as total cholesterol, associated with chronic diseases.

The Smith machine overhead press works your shoulders and triceps. A substantial piece of equipment, the Smith machine is not available in every fitness facility or home gym. If your workout calls for Smith machine overhead presses, you can perform barbell or dumbbell shoulder presses instead.

The BOSU balance trainers are versatile exercise tools that are shaped like half-circles, featuring a curved side and a flat side. You can stand, sit, lie or lean on the device, which produces different challenges, depending on whether you put the flat or the curved side on the floor.

Biceps, triceps and forearms are the main muscles of your arms that need strength training and conditioning. A variety of bicep curl, forearm curl and bench press exercises can provide an optimum workout for these muscle groups and thereby improve your upper body strength.

Unless you want to send your fellow gym members scrambling to get out of the way, you have to secure your weights to the barbell. None of the clamps or collars are hard to figure out, but if you're not sure if you're attaching them correctly, ask.

Cross training simply refers to participation in a variety of workouts or training regimens in addition to your specialty. Cross-training shoes, then, must provide support during activities such as jogging, bicycling, weightlifting and sprinting.

The idea of toning muscles and shedding unwanted pounds, without increasing the intensity of your workout, sounds too good to be true.

Smartphones, like the iPhone, can be convenient tools to help you manage your weight loss. You can download a variety of applications — many of which are free — that help track the calories you take in from food, as well as tracking the calories you burn through exercise.