Kettlebells, which come in varying weights, are often thought mistakenly to be the preserve of strongmen and extreme athletes.
Steve Cotter, a former Kung Fu competitor and the founder and director of the International Kettlebell and Fitness Federation, said part of the problem was that the kettlebell was marketed as a hard-core tool that implied intensity.
"It prevents beginners from giving it a shot," said Cotter in an interview. But the San Diego-based author of Kettlebell Training: 95 exercises for strength, toning, stamina and weight loss said novices should not be deterred.
"If you only have 30 minutes a day to commit to exercise, the kettlebell is an all-in-one, hand-held gym," he said.
Start off slow
The key to kettlebell training, Cotter added, is incremental progression. He recommends starting off with light weights, using one or two basic moves like the swing, during which the exerciser moves the kettlebell between the legs like a pendulum, forward and up and then back and down.
Normal, healthy women might begin with an eight-kilogram kettlebell, he said, while men can start with 16-kilograms.
"It sounds pretty heavy, but it's not the same approach as a dumbbell because you're swinging it, relying on inertia," Cotter explained. "It's more on the endurance side."
Because the center of mass extends beyond the hand, the kettlebell allows for ballistic, or fast, swinging motions that combine cardio-respiratory, strength, and flexibility training.
The result is an all-around, functional fitness workout that mimics everyday activities such as shoveling snow or working in the garden, he said.
Full range of motion
Amy Dixon, who teaches Kettlebell Power, a group class at an Equinox Fitness center in Los Angeles, said the workout is beneficial because it puts the body through so many ranges of motion.
"Your body is completely integrated, so you're moving everything," said Dixon, the creator of "Raise Some Bell - The Ultimate Kettlebell Core Workout" DVD.
She calls it "one of the best pieces of equipment that's been around for centuries."
For Richard Cotton, spokesman for the American College of Sports Medicine, the appeal of the kettlebell is its practicality.
"Kettlebells are inexpensive. They don't take up a lot of space, and they enable a variety of exercises," Cotton said. Unlike free weights, which tend to be linear, kettlebells work across all planes, he explained.
"I think they're here to stay among a wide population ... I could even see senior kettlebell workouts, so long as they take it easy," said Cotton, who advises people to progress slowly, starting with light weights.
Cotter stresses that there's nothing mystical about working with kettlebells. But lifting with the back is incorrect, he said. The back should be flat, with creasing at the hips.
"There's no boredom to it," he said. "Every workout can be different, and it feels almost like dancing."