It is my opinion that kettlebells are one of the most over-utilised pieces of equipment I see in a coach’s arsenal. Kettlebell can certainly be used effectively to increase strength in a novice, but so can almost any weighted object. What is more concerning is the amount of strength and conditioning programmes now utilising the kettlebell as a means for overload in advanced athletes. Combat sports in particular seem to have a strong affinity for the cannon-ball shaped implements.
So, what exactly is my issue with kettlebells about?
They are poor at loading the lower body
The most common exercises that kettlebells are used for are of course, kettlebell swings. The problem here is that unless the person doing the swing has a very low strength level, they are unlikely to get much of a strength adaptation from the kettlebell.
Think about it this way: the heaviest kettlebell in most gyms is usually no heavier than 40-50kg. Realistically, any lower body exercise you are going to do with a kettlebell is going to be some variant of a squat or deadlift. After just a few months of training, most people would be capable of doing reps with that weight in the squat and the deadlift.
But what about single leg work like lunges and single-leg RDLs? That leads me to my next point.
Dumbbells do (almost) the exact same thing
For almost every useful exercise I can think of doing with a kettlebell, you could also just save your money and use dumbbells instead. Lunges? Hold a dumbbell. Bench presses? Dumbbell. The list goes on.
I would even argue that kettlebells present a unique problem for upper body pressing because if you are pressing heavy weight, the bell will dig into the bones of your wrist and forearm. Why make yourself more uncomfortable for no extra benefit? Any pain being experienced during an exercise is only going to take away from the focus you should be spending on moving the weight with perfect technique.
What are the benefits of kettlebells?
One interesting feature of most kettlebells is the handle. They tend to be a lot thicker than those on dumbbells or barbells. For this reason, kettlebells may be a good option for grip training.
I have also read anecdotal reports from coaches claiming that kettlebell curls seem to be particularly good for high levels of bicep activation because they reinforcing good technique. One rationale given for this is that if you try to use a swinging motion (one of the most common technique errors in curls), the bell will bang into your arm. Maybe a useful approach?
Credit: Cressey Sports and Performance YouTube page
Additionally, I have found bottoms-up kettlebell presses to be a good tool for teaching correct vertical pressing biomechanics. The reason being because in order to successfully press the bell overhead, the forearm must be perpendicular to the ground and the wrist must be stacked directly over the elbow. However I would only use this exercise as a warm up because its inherent instability makes it too hard to load for strength training purposes. In an extreme case where a new trainee just couldn’t figure out how to press overhead effectively, I would consider using this as a training exercise.
I am not sure why, but this is an exercise that has become very popular. It seems to be something to do with the ‘functional’ appeal of getting off the ground in a position that is hard to stabilise and makes your core muscles feel strained. However training also has to be specific, and the Turkish Get-Up is not a similar movement to most sporting actions. Aside from this, there is a reasonably large amount of training literature that suggest heavy compund movements such as squats, deadlifts, pull-ups, etc. are superior for trunk muscle activation than light, stability-based exercises such as these. Exercises also have greater transfer to a range of sporting movements such as jumping and sprinting. It is not necessarily an exercise without merit, it just is not as functional or sport specific as it is often promoted to be.
In summary, kettlebells are poor instrument for increasing strength in non-beginners, and present few advantages over dumbbells. Do not mistake for claiming that kettlebells are useless, it’s just that their usefulness is overstated in the mainstream training media. The positives of kettlebells are that they have some highly specific uses such as grip training, and as a teaching tool for the curl and overhead pressing.