Effects of Weightlifting vs. Kettlebell Training on Vertical Jump, Strength, and Body Composition
A review of:
Otto WH, Coburn JW, Brown LE, Spiering BA, Effects of Weightlifting vs. Kettlebell Training on Vertical Jump, Strength, and Body Composition, J Strength Cond Res. 2012 Feb 15. [Epub ahead of print] [http://www.ncbi.nlm.nih.gov/pubmed/22344061]
Not surprisngly, each reached similar conclusions, but with emphasis on slightly different things based on their own experiences and biases.
I was quite interested to post about this because I feel I can approach this from a slightly different angle: that of a (low level it must be said) kettlebell sport athlete as well as a trainer versed in the World Kettlebell Club (WKC) methods.
What The Study Is About
The title pretty much says it all for this one.
The researchers observed (rightly so) that there is scant evidence (at least on this side of the Iron Curtain) on the effects of kettlebell training.
So they set out to quantify the effects of kettlebell training in comparison to that of traditional weightlifting methodology.
What Was Tested
The following were tested both pre-intervention and after 6 weeks of twice weekly training sessions using either kettlebells or barbells:
- Body mass
- Vertical jump
- Back Squat
- Power clean
- % Body fat
There is potentially a problem here, which the authors inadvertently noted. Weightlifting has been shown to have a positive effect on vertical jump, which makes sense when you look at the direction force is being applied – vertically.
One of the purported benefits of kettlebell training, is the fact that you can swing it between your legs. This means the forces are primarily horizontal. There wasn’t really any testing of horizontally applied strength and power – important because it is becoming increasingly recognised that power productin is vector (or directionally) specific.
A good (and simple to administer) test to include would have been the broad jump, this would have at least given a little more balance to the testing procedure.
What Was Done
A group of young men (19-26 years old), with at least a year of resistance training experience were randomised into two groups: kettlebell and weightlifting (it was noted that none had any extensive experience with kettlebell training or weightlifting).
The weightlifting group performed 3 exercises, using 80% of a pre-determined 1RM:
- High pull
- Power clean
- Back squat
Whilst the kettlebell group also performed 3 exercises, using a 16 kg kettlebell:
- Accelerated swing
- Goblet squat
Each group went through the testing procedure before undergoing 2 training sessions per week for 6 weeks, with at least 72 hours between sessions.
The first 3 weeks subjects performed 3×6 (swings/high pulls), 4×4 (accelerated swings/power cleans) and 4×6 (goblet squat/back squat). The next 3 weeks the sets/reps changed to 4×6, 6×4 and 4×6 respectively.
Subjects were told to eat their normal diet throughout.
It’s really interesting that the authors selected the exercises they did. I would have liked to see them include a kettlebell snatch there as a comparison to a power clean, rather than an accelerated swing. I feel this would give a few more benefits, as there is a catch phase, just as there is with the power clean (although the eccentric component is much less).
The BIG issue, which is pretty obvious, is the loading used. When you are testing strength, and you only allow one group to use a 16 kg kettlebell, whilst the other is using 80% of their 1RM, there is a bit of a problem.
Without having a degree in exercise science, you could probably work out that lifting something heavier will make you stronger.
The other issue, which is where I feel having experience with the WKC will help is in the programming.
Kettlebells aren’t really designed for low rep training. Sure, you can do it, just as you can swing a dumbbell and do high rep Olympic lifts, but you will be short changing yourself by using the tool inappropriately.
There is a reason powerlifting uses the barbell bench, and not the dumbbell bench. It isn’t practical to keep using bigger and bigger dumbbells.
The same applies with kettlebells. The Russians worked this out long ago, and realised that for sport, doing as many repetitions as possible was the most appropriate goal.
Now sport training is not necessarily athletic preparation, or general fitness training, but the lessons should filter down.
The power of kettlebells is in their use in high repetition ballistic lifts (swings, cleans, snatches, jerks). Sure they can be used for other applications, but outside their primary purpose, their is always compromise.
It would have been nice if the study had tested something like high repetition swings, snatches and heavier goblet squats, and then seen if there is any maximal power and strength carryover from that.
It could have also tested the effect of low rep weightlifting (as it did) on power and strength endurance carryover.
I feel that it would have given us some more useful information – is one methodology more of an ‘all rounder’ than the other?
What Was Found (Results)
Both the kettlebell and weightlifting groups significantly (P<0.05) improved their vertical jump, power clean and back squat. The weightlifting group improved their back squat significantly more than the kettlebell group. Body mass and body fat did not change.
As it is, it basically told us what we already knew: you need to lift heavy to build strength and power, power is vector specific, using light weights doesn’t build strength as effectively as heavy weights and that without change to diet, exercise alone has minimal impact on body composition.
What This Means To You
As I have talked about in the past, I feel a blend of weightlifting and kettlebell training offers superior all round benefits, and unless you are training for a very specific sport, you would be wise to include them both in your training.
It is good to see a growing body of research on kettlebell training, but until the body of research is more complete, I advise deferring to experienced coaches, after all, empirical evidence should never be completely discounted.