Video by Erin Wisdom

"Round" and "fit" generally aren't terms considered to be closely related.

For that reason, it seemed like it would be fun and somewhat ironic to identify round objects that can go a long way in keeping you from developing - or in helping you shed - a shape like theirs. And as it turns out, there are several that not only provide good workouts but also won't break your bank account.

One of the most obvious is the stability ball, which ranges in price from about $10 to $25.

"The funny thing is, they call this a stability ball, but it's anything but stable," says Bob Boyles, a certified strength and conditioning specialist and the owner of Body Image Personal Training. "It requires muscles to keep it stable ... Your core area has to be really good, or else you'll fall off."

Cody Bradford, assistant manager at AEC Family Fitness, adds that another benefit of the ball is how it allows for multitasking - developing core strength "plus whatever you're doing with it, like weights or bands."

This multitasking-type workout can take the form of using dumbbells or doing crunches while sitting or lying on the ball, doing squats with the ball braced between your back and a wall and, really, anything else you can think of.

"It's kind of up to your own imagination," Mr. Boyles says.

Another piece of equipment that's very versatile - not to mention round - is the kettlebell, which looks somewhat like a bowling ball with a handle on top (or like a tea kettle; thus the name). Mr. Boyles has a set of 10, ranging in weight from 10 to 82 pounds, that cost $1,500. But kettlebells on the lighter end of the spectrum are available individually from stores like Wal-Mart, Target and Dick's Sporting Goods, often for less than $50. They can be incorporated into squats, lunges, windmills and a number of other exercises.

"Their shape allows you to utilize the weight for explosive, fast movements, so you're getting a cardio and overall strength workout," says Mr. Bradford, adding that using the same amount of weight in dumbbell form for this kind of exercise can be awkward.

Another advantage to working out with kettlebells is that they're good for using in functional exercises - ones that engage the entire body and cause it to move like it does in everyday activities.

"When you grab a weight and fling it around, it requires the whole body to work," Mr. Boyles says. "Everyone's always looking for a unique way to train, and once you get to the point where you're swinging them around, you're thinking, 'This is pretty neat.'"

Even some of his very in-shape clients have been surprised by how fatigued they become through the swinging, lifting and squatting of kettlebell exercises, he adds, which is something Jason Atkinson has found to be the case. Mr. Atkinson usually weight-lifts at the Wesley Center but comes to Mr. Boyles' gym periodically just to work with kettlebells.

"As with anything, your body gets used to using regular bars and doesn't make any more gains," he says. "(Kettlebells) are good for changing things up, and I think they're something that's getting more attention."

Medicine balls are another option, Mr. Boyles says, that are good for explosive throwing or pushing movements and are especially appropriate when working out with a partner. They're versatile, too, and can be incorporated into push-ups and core exercises. They vary in price according to weight; 2-pound medicine balls are available for as little as $15, for example, while 30-pound medicine balls can cost about $80.

A cheaper piece of equipment that can provide quite a workout is an exercise wheel, Mr. Boyles says. Available for as little as $10, the small, plastic wheel with handlebars on either side works muscles in the abdomen, arms and back when you stretch out from a kneeling position until your upper body is parallel to the floor, then roll the exercise wheel back until you're in your starting position again.

Lifestyles reporter Erin Wisdom can be reached at ewisdom@npgco.com.