Do Kettlebells Actually Make You Stronger?

What does science actually say about strength training with kettlebells?

If you’re going to look at any kind of training such as kettlebell training, you need to know if it’ll do what you want it to do. While I do think that your enjoyment should play a factor, as previously noted, I also think you need to understand what will happen if you engage in a given training modality.

With barbells and dumbbells, even with calisthenics, people already generally know what to expect. If you lift weights, you’ll get stronger and can get bigger muscles. Similarly with calisthenics.

But kettlebells are different animals. Despite having been around for centuries, few people really understand what they can really do.

That includes me.

So, as part of this ongoing quest to figure them out, let’s look and see if they can really make you stronger.

First, let’s note one important thing. These are weights. Biology and the principle of progressive overload tell us that if used correctly, you will get stronger regardless of what form that weight takes.

But let’s be honest here. That’s not really enough. We want specifics. I mean, kettlebell training suggests more than the shape of the weight. It also suggests how they should be used.

That means we need to know if that methodology will yield specific results. In this case, will such a system make you stronger?

That’s a good question, so I looked at a handful of studies.

Perhaps the most famous study that looked at kettlebell training for strength gains decided to take a look at kettlebells and compare them to Olympic weightlifting. It found that progress was much more noticeable from a strength and power standpoint with Olympic weightlifting.

But there’s a problem with this study. Josh Henkin, writing for Dragon Door’s website–it should be mentioned that Dragon Door sells kettlebells and a lot of kettlebell-focused publications–took a look at the study and offers his take on the problem with the above-mentioned study by Otto et al.


What has the research TRIED to show us? Well in one study by Otto et al. (1), the effectiveness of kettlebell training versus weightlifting was put to the test. The impact of these two forms of training were measured by vertical jump performance, strength, and body composition. 

The results? Both showed improvements, but weightlifting was showed to be far more effective especially in performance of the back squat and power clean. Get rid of those kettlebells right?! Well, not so fast! 

In the study, researchers compared the use of a 16kg kettlebell to that of loads of 106kg (35 pounds vs. 232 pounds for our metric challenged friends) used by the weightlifting group. Now I am one of the first to say that weight is not all equal, but even THIS is a bit much. Why weren’t two 48kg kettlebells used instead? I mean that would have been still 10kg lighter and I think would have been a much more interesting comparison. 


Imagine what could be found with even a more challenging load of 32kg for more trained males rather than the 16kg weight that is used as a great baseline of kettlebell training. This is where I am always confused by coaches saying tools are tools and weight is weight. If this is true, how come the same amount of weight used wasn’t even close! 

It’s an interesting point Henkin makes. After all, 106 kg is 233.2 lbs. That’s some fairly heavy weight to move, especially in an explosive manner. Meanwhile, the 16 kg kettlebell is considered by some to be an entry-level weight (more on that below).

After all, this study used young men age 19-26 with at least one year of resistance training experience. In other words, they weren’t rank beginners, so why the disparity in weight?

Yet despite that, the actual study in question does report an improvement. It just argues that it’s not as good of an improvement as it would be if they’d used a much heavier weight in barbell form.

However, not all the data is negative.

For example, we have an experiment by Wade and colleagues. She and her fellow researchers looked at kettlebell training for Air Force personnel by dividing them into three groups. One trained with just the kettlebell, one with the kettlebell and added a run, and one just engaged in the Air Force PT program.

What they found was:

Results: Twenty subjects completed the study. There were no statistically significant changes in 1.5-mile run time between or within groups. The 40- yard dash significantly improved within the KB swing (p ≤ .05) and KB + run group (p ≤ .05); however, there were no significant differences in the traditional PT group (p ≤ .05) or between groups. Maximal push-ups significantly improved in the KB + run group (p ≤ .05) and trends toward significant improvements in maximal push-ups were found in both the KB (p = .057) and traditional PT (p = .067) groups.

Now, understand that the subjects were engaging in a one-handed swing. They weren’t adding in calisthenics movements, yet there was apparently some improvement, though not statistically significant.

Despite this, the two kettlebell training groups had an improved maximal pushup performance to some degree, seemingly more than the PT group.

Now, one would expect subjects engaging in PT training–typically a replication of the testing itself–to show improvement on maximal pushups, but the kettlebell groups?

For one thing, the researchers actually used progressive overload.

KB weights were selected based on proper technique execution and were progressively increased based on participants’ technique and perceived effort throughout the study. Male subjects in the KB group and the KB + run group began the study using 8kg to 12kg KBs and finished the study using 12kg to 18kg KBs. Female subjects began the study using 6kg to 8kg KBs and progressed to 10kg to 14kg KBs the final week of the study.

I’d like to note that these weights still tend to be on the low side for recommendations. In Enter the Kettlebell, Pavel Tsatsouline recommends most men start with a 16 kg kettlebell and move from there to a 24 kg one before progressing to a 32 kg kettlebell.

Meanwhile, women start with an 8 kg kettlebell, generally, and progress to a 12 kg one before eventually hitting the 16 kg mark.

In other words, Wade and company actually lowballed it with the weight and still showed significant improvement in maximal pushups. (It probably should be noted that the kettlebell only group also dropped from a mean body fat percentage of 23.2 to 20.7 percent body fat).

For what it’s worth, in mean numbers, both the kettlebell only group and the control group showed improvement in situp performance, though not enough to be considered statistically significant.

Regardless, we clearly see an improvement in strength over a 10-week study period for an exercise not being trained at all by two groups and no real replacement was implemented, though I should remind both you and myself that the kettlebell only group didn’t quite reach the point of statistical significance. Yet they were closer than the calisthenics group, oddly enough.

No, don’t ask me how.

However, Wade and company are far from the only ones to support the idea that kettlebells are useful for strength development.

In a study published in 2013, Manocchia and colleagues noted some interesting things as well.


A significant group × time interaction was found in the bench press. A post hoc pairwise comparison revealed that the magnitude of improvement was significantly different in EXP (39.9 ± 22.6 to 54.1 ± 30.3 kg) as compared with that of CON (54.5 ± 28.8 to 58.2 ± 36.5 kg, p < 0.05). Additionally, a main effect for time was found for the clean and jerk (EXP; 34.9 ± 3.6 to 39.1 ± 3.8 kg vs. CON; 40.1 ± 5.4 to 40.9 ± 5.8 kg, p < 0.05).


Notably, a group × time interaction for the clean and jerk and the back extension approached statistical significance (p = 0.53). No significant changes were observed in any group for the vertical jump (p = NS). The range of weight lifted for the bench press across all the subjects was 45–215 and 20–79 kg for EXP and CTRL, respectively. The range of weight lifted for the clean and jerk varied across all the participants from 30–145 and 9–59 kg for EXP and CON, respectively. 

In other words, they too found increased strength in a pectoralis major-focused compound movement despite not engaging in that particular activity.

The difference, though is, that Manocchia did include push-ups and isometric push-ups on weeks one and two of the study and a kettlebell chest press on week four. of the five-week mesocycle.

Still, for a program that didn’t have a lot of focus on what we tend to think of as a chest movement, that’s pretty significant.

The study also found a 25 percent improvement in clean and jerk strength, though, which is significant all on its own as this runs counter to what Otto and company found.

It’s not just the chest that benefits, either.


The study also found a 25 percent improvement in clean and jerk strength, though, which is significant all on its own as this runs counter to what Otto and company found.

Another study also found that it wasn’t just the chest that beefs up.

A study by Lake and Lauder compared kettlebell training to barbell training in a couple of lifts and found that there was statistically no difference between the training modalities with regard to strength gains.

Again, they were using what many consider to be fairly entry-level kettlebells. They assigned subjects under 70 kgs a 12 kg kettlebell. Those over that weight were given a 16 kg kettlebell. There was no allowance for pre-existing strength levels.

Despite this, the study found sufficient improvement to argue the difference was a wash from a statistical standpoint.

Conclusion

So what we see is that clearly, kettlebells will assist you in gaining strength. This isn’t really in doubt. The one study we have arguing that it’s not particularly effective was poorly designed and put kettlebells at a profound disadvantage, and even then it found that kettlebells were still effective, just not as effective as barbell lifts.

However, let’s also temper some of this a bit (that talking as much to me as anyone else). Wade’s findings for the kettlebell only group didn’t reach statistical significance with regard to strength gains, though further research may help with that as her sample size was rather small.

Mannochia and colleagues used a kettlebell, but they included calisthenics exercises–the pushup and the isometric pushup–along with one pressing movement where the kettlebell was merely swapped for what many would consider a more traditional implement.

Lauder and Lake’s study shows lower-body gains on part with weight training, though, despite low weights utilized, though.

When you take these three studies, plus the criticism of Otto et al, it’s hard to argue that there aren’t at least some strength benefits to be gained from kettlebell training.

That’s not to say there aren’t a lot of questions. For example, just how pronounced a difference are we talking about here? While Lake and Lauder found no difference to speak of, that’s looking at power generation rather than pure strength. There’s a difference.

Otto and company attempted to answer that question, but the aforementioned issues are a serious impediment to taking that research at face value on the subject.

Other questions I have include things such as what is the ideal training protocols for developing strength with a kettlebell? I mean, I could just use it like an oddly shaped dumbbell, but that would eliminate some of the other advantages of the kettlebell.

And none of those touch on the fact that there’s still a whole lot more research to be done, both by me looking at the current literature and by researchers looking to write that literature.

Still, it’s good to know just what this particular bad boy can do, now isn’t it?

Author: Tom

Tom is a husband, father, novelist, opinion writer, and former Navy Corpsman currently living in Georgia. He's also someone who has lost almost 60 pounds in a safe, sustainable way, so he knows what he's talking about.

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