The Efficacy of Kettlebell Training
What are Kettlebells?
The best way I can describe a kettlebell is that it looks like a heavy metal ball with a handle attached to it. I read about them about 12 years ago when a man from Russia named Pavel was making the scene in the personal training circles. He was amazingly strong and he used kettle bells almost exclusively for his training. This actually makes sense, for the Russian strongmen from the 1700's were the ones who developed them. They have since gained in popularity here in America as of late. Many gyms have them, and there are a number of small studios that use only kettlebells for their training programs.
The Claims of Kettlebell Training
Kettle Bell proponents claim that the workout can have the same benefit as doing a 30 minute strength training program followed by a 30 minute aerobic program. In effect, one can build as muscle and burn as much fat with only 20 minutes of kettlebell training that it would take for one hour of strength training and aerobic training combined. Are the claims true? The American Council On Exercise (a certifying body for personal trainers) set up a study to find out.
To analyze the effects of a kettlebell workout, ACE recruited 10 volunteers who were experienced with kettlebell training. The researchers started by putting the volunteers on a treadmill to determine oxygen consumption, heart rate, and rate of perceived exertion (how hard the exercise felt to the volunteer at certain heart rates). The researchers then had the volunteers do a five minute kettle bell VO2 max snatch test to establish a baseline of their specific kettlebell fitness. This was used to see what size kettle bell the volunteers needed to use for the workout. The protocol went like this:
- Fist minute: 8 reps at a rate of one snatch every 7 seconds.
- Second minute: 12 reps at a rate of 1 snatch every 5 seconds.
- Third minute: 15 reps at a rate of 1 snatch every 4 seconds.
- Fourth minute: 20 reps at a rate of 1 snatch every 3 seconds.
- Fifth minute: The subject went all out, performing as many snatches as they could until fatigue.
Meanwhile, heart rate and oxygen consumption were measured during each stage, and blood lactate levels were checked three minutes after the completion of the test.
The number of snatches each subject completed during the final minute of the test determined the number of snatches they would be asked to perform during the actual kettlebell testing. As an example, if a subject completed 24 snatches for the final minute, this number was divided by 4 and they were required to complete at least six snatches during each timed 15 second period of the 20 minute kettle bell workout. This protocol determined the baseline. The real workout was done on another day.
The real workout was executed as follows: after a warm-up, the subjects would do 15 seconds of one arm snatches with the dominant arm, rest for 15 seconds and then do another 15 seconds of one arm snatches with the other arm. The workout continued like that (15 seconds of work followed by 15 seconds of rest) for 20 minutes followed by a cool down.
Throughout the workout, researchers monitored each subjects heart rate at 60 second intervals, followed by a blood lactate test which was taken immediately after the workout (the reason for the blood lactate test is to determine how much work was done anaerobically).
Here is what the researchers learned. For the 20 minute workout, the subjects burned about 272 calories. A closer look showed that the subjects burned 13.6 calories a minute aerobically, and another 6.6 calories anaerobically. This amounted to a total of 20.2 calories a minute. The average heart rate for the duration of the workout was 86 to 99% of the kettle bell HR max for for all subjects. In real numbers, the heart rate averaged 164 beats per minute.
The researchers were impressed. The intensity, in their words, equalled running a six minute mile pace. The only thing one of the researcher could compare it to was cross country skiing uphill at a fast pace. The researchers concluded that it was much more effective than a conventional weight training program because it uses whole body movements done very quickly. All in all, kettle bell training proved to be a very efficient way to get a productive workout in a short amount of time.
My Two Cents Worth
Personally, I am impressed with the study. It was unbiased. They used volunteers that had training experience so that the learning curve variable was taken out of the equation. The researchers established a baseline level of fitness and intensity of the volunteers, and used heart rate, VO2 max, and blood lactate level testing to see what really goes on with the body. Then they pushed the volunteers...and recorded what happens.
As for the results? Ditto there too. This study did show that kettlebell training done with the proper intensity is very effective, especially compared to a conventional strength training program. Like other productive exercise programs, this particular workout that was designed by ACE with the kettlebells included 3 important aspects:
- An elevated heart rate for a prolonged time.
- A good amount of work above the anaerobic threshold.
- Forcing the body to utilize the fast twitch fibers.
A program like that will always make the body stronger, healthier, and more shapely. I do not use kettle bells in my programs. I prefer barbells, dumbbells, functional training machines and bands. But from the results of the study, kettlebells can be a useful tool in your exercise program. If the idea of swinging kettlebells jazzes you to push your workouts harder, then go for it. Just remember this: like all exercise programs, start off with lighter resistance and polish your form before you do the hard work. If need be, hire a trainer with experience using kettlebells.
Source: Fitness Matters, Volume 16, Issue 1. January/February 2010. A publication from The American Council on Exercise.