Question: How are kettlebells different from other weights?

A kettlebell is a medieval looking thing that closely resembles a cannonball with a thick handle. Their exact origins are a bit cloudy but the two prevailing theories are that the kettlebell originated either in the Scottish Highlands or back in the 1700s in Russia when the word first appeared in a Russian dictionary. But, as these things often do, the kettlebell has recently had a resurgence. And proponents of the modern-day kettlebell phenomenon claim that it provides enormous improvements in strength, balance, and cardiovascular fitness in a shorter period of time.

The strength and balance aspects are easy. Kettlebell exercises generally involve compound movements, which engage multiple muscle groups, and are preformed quickly. Any strength training has the potential to improve balance but the fast, swinging movements of a kettlebell workout would logically challenge your balance even more.

But what about the claims of weight loss and cardiovascular health? What does science say?

It appears that science agrees with these claims, for the most part.

An independent study conducted by the American Council on Exercise tested the efficacy of kettlebells in delivering the aerobic workout that they promise. The study produced interesting results. An intense 20 minute workout burned around 400 calories both aerobically and anaerobically, roughly equivalent to running a 6 minute mile. The subjects' heart rates also skyrocketed to working at an average of 93 percent of their maximum. To put this in perspective, the typical workout is done at about 70 percent. The researchers concluded that the kettlebell swing workout (detailed in the study) meets the industry recommendations for improving aerobic capacity which means that it is an effective form of strength training that will also help people to lose weight. It should be noted that all of the subjects were trained and experienced with the use of a kettlebell.

But always remember: there is no such thing as a magic bullet. Kettlebell promoters make some outrageous claims like kettlebells can increase running speed and provide dramatic improvements in strength and body composition in "just minutes a day!"

That sort of language should always send up red flags.

Kettlebells can be a very beneficial training tool when used to supplement, not replace,other forms of strength training. The movements involved in kettlebell workouts are fast and dynamic with lots of room for injury if  your form isn't perfect and if your muscles are weak. Kettlebells should be worked up to using other forms of strength training and you should start slow, at a low weight.

The American Council on Exercise recommends women starting at 8 to 15 pounds and men using 15 to 25 pounds. As the exercise becomes easier, increase reps and decrease recovery time between sets. If that's still too easy then, and only then, should you increase the weight of the kettlebell.

Click here for more information on the study and kettlebell exercises.