Your gym should have a selection of kettlebells and dumbbells, because they are both incredibly useful pieces of training kit, but is one superior to the other?

Well, that depends what you’re trying to achieve:

• Improve explosive power
• Enhance Biomechanics
• Gain strength
• Build muscle

You see, the different benefits to kettlebells and dumbbells are not so much about the equipment itself (they’re just pieces of iron), but rather the exercises they enable you to perform. The odd shape of kettlebells works very nicely with explosive, athletic movements like the kettlebell clean, which lend themselves well to the majority of contact sports, whereas barbells and dumbbells are built for handling heavy loads.

Let’s get into the science.

Table of Contents

• Kettlebells vs Dumbbells: Explosive Power
• Kettlebells vs Dumbbells: Biomechanics
• Kettlebells vs Dumbbells: Gain Strength
• Kettlebells vs Dumbbells: Hypertrophy
• How To Get The Best Results…
• Who Is Russ Howe PTI?

Kettlebells vs Dumbbells: Explosive Power

Originating in 1700s Russia, kettlebells (‘Girya’) are renowned for their odd shape.

It is this odd shape which helps them to excel at fast movements which utilize a lot of momentum, making them a highly effective tool for building explosive strength!

Athletes are able to mimic lots of the movement patterns they’ll perform in their chosen sport because the focus is on speed and power. That’s why you’ll typically see MMA athletes, baseball players, and footballers incorporating kettlebell movements into their training programs, and the superior grip placement of the bell makes it ideal for this type of training. (1)

Alongside the benefits of increased sports specificity, a 2012 study published in the Journal of Strength and Conditioning Research found that kettlebell training produces similar increases in explosive power output to to traditional weight training – but with significantly less load on the joints, making it a solid choice for athletes looking to steer clear of injury. (2)

Winner: Kettlebells

Kettlebells vs Dumbbells: Biomechanics

Athletes who pay no attention to exercise biomechanics get injured more often.

A good example of this can be seen by looking back at the WWE wrestlers of the 1980s and 1990s.

Most of those guys trained exclusively like bodybuilders in order to look good and sell tickets, only to wind up riddled with injuries. This happens because the majority of classic bodybuilding movements take place in the sagittal plane (up and down, back and forward), but most sports, and some would argue life itself, use the transverse plane (twisting, catching, etc).

This is where kettlebells really excel.

For instance; a 2013 study from Denmark which used EMG to track muscle activation in the hamstrings found that kettlebell swings activate the semitendinosus (medial hamstring) more than the biceps femoris (lateral hamstring). The semitendinosus plays a greater role in running, so while you could effectively train your hamstrings to look good with either kettlebell swings or a seated leg curl, swings are a much better choice for someone following a sprint-based training program. (3, 4)

They also produce a huge amount of horizontal force. Studies show that horizontal ground reaction forces display greater increases than vertical ground reaction forces when accelerating to high velocity, so this is another reason why kettlebell swings are a fantastic choice for sprinters! (5, 6)

Winner: Kettlebells

Kettlebells vs Dumbbells: Gain Strength

Your overall strength refers to the sheer amount of weight you can lift (your 1RM on a squat, etc).

This is where momentum shifts in favor of traditional barbells and dumbbells because they allow you to load the exercise with far greater resistance, and their shape is built for brute force, making them perfect for gaining strength.

To put this into context, a 2012 study from researchers at California State University, Fullerton compared the strength gains made from a selection of kettlebell-based exercises and barbell/dumbbell exercises. The exercises were chosen due to their similar movement patterns:

All of the participants saw a strength increase, but those using barbells/dumbbells saw the greatest gains.

This included a 15% increase to their squat max (compared to a 5% increase for the kettlebell trainees), a 4% boost to their vertical leap (versus 1% for the kettlebell trainees), and a 10% improvement to overall strength (compared to 4% for the kettlebell trainees). (7)

Winner: Barbells / Dumbbells

Kettlebells vs Dumbbells: Hypertrophy

You can build muscle with either, but the training style which has been shown to maximize results is better suited to dumbbells.

You see, the two best ways to build muscle involve subjecting your muscles to increased resistance and more time under tension.

An increase in resistance is called progressive overload (think gradually increasing the weights on the bar over time). Barbells and dumbbells are perfect for this, because they allow for heavier loads to be lifted. The main drawback with this type of training, though, is that eventually everybody hits a ceiling in terms of how much weight they can lift on any given exercise, so that’s where a second muscle building pathway – time under tension – comes into play. (8)

A 2012 study published in the Journal of Physiology suggested that the sweet spot for muscle growth is 40-60 seconds of continuous tension. (9)

Considering kettlebell-based training is best applied to explosive movements which generate a lot of momentum, dumbbells are a considerably better choice.

Winner: Barbells / Dumbbells

How To Get The Best Results…

As you can see, kettlebells are better than dumbbells at certain things, but not at others.

This is where clever programming comes into play.

You see, I believe every tool in the gym has a purpose. This includes kettlebells, dumbbells, barbells, resistance bands, cable stations, machines, the Smith Machine, bodyweight stations, and more. The real secret to success is learning how to choose the right kit to match your own training goals, and if those goals involve building explosive power and improving biomechanics for sport, then kettlebells would be a great choice for you.

I’ll leave you with the conclusion of a comprehensive 2014 meta-analysis published in the Strength and Conditioning Journal, which looked at the findings of 23 earlier studies on kettlebell training:

“The majority of studies support the use of kettlebells for improving power, but the evidence for using them for improving strength and aerobic fitness is still equivocal. Studies investigating the biomechanical properties of kettlebell training have been more fruitful; researchers have so far found that kettlebell swings in particular have certain features that may make them useful for training athletes.” (10)

References:

1. Vancini R. L., et al. Kettlebell Exercise as an Alternative to Improve Aerobic Power and Muscle Strength. J Hum Kinet (2019).
2. Lake J. P., et al. Kettlebell swing training improves maximal and explosive strength. J Str Cond Res (2012).
3. Zebis M. K., et al. Kettlebell swing targets semitendinosus and supine leg curl targets biceps femoris: An EMG study with rehabilitation implications. Br J Sports Med (2012).
4. Jonhagen S., et al. Amplitude and timing of electromyographic activity during sprinting. Scand J Med Sci Sports (1996).
5. Lake J. P., et al. Mechanical demands of kettlebell swing exercise. J Strength Cond Res (2012).
6. Keogh J. W. L., et al. Transference of Strength and Power Adaptation to Sports Performance-Horizontal and Vertical Force Production. Str Cond J (2010).
7. Otto W. H., et al. Effects Of Weightlifting Vs. Kettlebell Training On Vertical Jump, Strength, And Body Composition. J Strength Cond Res (2012).
8. Krzysztofik M., et al. Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods. Int J Environ Res Public Health (2019).
9. Burd N. A., et al. Muscle Time Under Tension During Resistance Exercise Stimulates Differential Muscle Protein Sub-Fractional Synthetic Responses In Men. J Physiol (2012).
10. Bearsdley C. M. A., et al. The Role of Kettlebells in Strength and Conditioning: A Review of the Literature. Str Cond J (2014).

Who Is Russ Howe PTI?

Russ has been a personal trainer in the UK since 2002, and provided both training advice and full programs on this website since 2011.

His work has been featured in Men’s Fitness magazine, and the content on this website led to him being voted one of the world’s top 50 fat loss coaches by HuffPost.

Russ spends his time coaching men and women inside the legendary Powerhouse Gym, South Shields, and writing training tips for the 114,301 members of his popular free training e-mail (join it below).