I just replied to an email the other day about it from a reader.
“At 70 kgs weight and 85 grams of protein a day, can I increase muscle mass and boost my strength using kettlebells? How would I notice improvement in my muscle mass and strength?
“Will KB workouts alone be enough to build muscle mass and strength? There are some very conflicting insights on it on online forums.”
First, here’s what I said to this gentleman -
“Yes you can increase strength, but muscle will be harder . The current recommendation for building muscle is 1.6g/kg of bodyweight. How would you notice improvement? You wouldn't. You'd measure it objectively through your training log, a tape measure, and body composition measurements.
Yes. Resistance builds muscle and strength, regardless of the implement/ tool . The key is knowing how to organize your program to do so. Many, if not most people don't know how to do this - especially with kettlebells, so they say "kettlebells don't develop muscle" or "you can't get strong using kettlebells" or "kettlebells are an endurance / conditioning tool.””
Second, before we get to the “not knowing how design” part we have to consider the fact that there are many different reasons for muscle growth.
At the very least, we have the following:
Mechanical Tension and Mechanotransduction: Mechanical signals from resistance exercise are main stimuli for hypertrophy. These signals activate mechanotransduction pathways, which convert mechanical stress into cellular responses, encouraging protein synthesis and muscle growth (Wackerhage et al., 2019; Bamman, Roberts and Adams, 2018; West et al., 2010).
mTORC1 Signaling: mTORC1 is a pivotal regulator of muscle protein synthesis and ribosomal biogenesis, facilitating the growth of muscle fibers. It is activated by mechanical overload and nutrient availability, particularly amino acids (Wackerhage et al., 2019; Roberts kettlebell et al., 2023; Schiaffino et al., 2020).
Ribosomal Biogenesis: The rise in ribosome production enhances the muscle's ability to assemble proteins, supporting hypertrophy (Roberts et al., 2023; Bamman, Roberts and Adams, 2018).
Hormonal and Growth Factor Influence: While systemic hormones like growth hormone and testosterone have modest direct impact post-exercise, local growth factors such as IGF-1 affect muscle adaptation and growth (West et al., 2010; Schiaffino et al., 2020).
Metabolic Stress: Metabolic stress from resistance exercise, such as that generated by blood flow restriction, can also drive hypertrophy, although the exact metabolites involved are not well characterized (Wackerhage et al., 2019; Schoenfeld, 2010).
Third, the kettlebell, compared to the barbell or a dumbbell, possesses at least one unique property:
The offset handle.
The fact that the kettlebell balances on the back of your wrist or turns inside your palm and around your hand, landing on the back of your wrist…
And that causes your muscles and joints to engage more , increasing the tension both on your joints and muscles. Which, according to at least some of the aforementioned “hypertrophy mechanisms,” stimulates muscle growth.
Plus, the fact that you can swing the kettlebell through your legs and quickly elongate the muscles of your posterior chain (called “fast eccentrics”) and engage your abdominal musculature making it harder to breathe…
Also triggers a few more of those “hypertrophy mechanisms” depending on how you program your workouts.
Which actually gets us to “how to program your kettlebell workouts for muscle growth.”
I’ve found there are three basic , but reliable ways:
1- Program off a 5RM using the combined lifts, like the Clean + Press and Front Squat.
2- Program off a 10RM, also using some of the combined lifts, like the Clean + Press or Clean + Push Press.
3- Using Double Kettlebell Complexes and Chains like these.
Again, at the end of the day, it’s not that hard to build muscle using kettlebells. You just have to be
A - Willing to do the work.
B - Be smart about the work you’re doing.
Stay Strong,
Geoff Neupert.