I just responded 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 enhance my strength using kettlebells? How would I notice improvement in my muscle mass and strength?
“Will KB workouts alone be sufficient to develop muscle mass and strength? There are some highly conflicting insights on it on online forums.”
First, here’s what I told this gentleman -
“Yes you can increase strength, but muscle will be tougher. The current recommendation for increasing muscle is 1.6g/kg of bodyweight. How would you perceive improvement? You wouldn't. You'd track it through your training log, a tape measure, and body composition measurements.
Yes. Resistance develops muscle and strength, regardless of the equipment . The key is knowing how to structure 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 explanations for muscle growth.
At the very least, we have the following:
Mechanical Tension and Mechanotransduction: Mechanical signals from resistance exercise are primary 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 critical 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 et al., 2023; Schiaffino et al., 2020).
Ribosomal Biogenesis: The rise in ribosome production supports the muscle's ability to produce proteins, promoting 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 encourage hypertrophy, although the exact metabolites involved are not well characterized (Wackerhage et al., 2019; Schoenfeld, 2010).
Third, the kettlebell, unlike the barbell or a dumbbell, does have at least one unique property:
The offset handle.
The fact that the kettlebell rests on the back of your wrist or rotates inside your palm and around your hand, landing on the back of your wrist…
And that forces 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 move the kettlebell through your legs and quickly lengthen the muscles of your posterior chain (called “fast eccentrics”) and compress your abdominal musculature making strength it more difficult to breathe…
Also involves a few more of those “hypertrophy mechanisms” depending on how you program your workouts.
Which actually transitions us to “how to program your kettlebell workouts for muscle growth.”
I’ve realized there are a few simple , but guaranteed ways:
1- Program off a 5RM using the double lifts , like the Clean + Press and Front Squat.
2- Program off a 10RM, also using some of the double 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 - Determined to do the work.
B - Be intentional about the work you’re doing.
Stay Strong,
Geoff Neupert.