For kettlebell practitioners, there are two types of swings. The two-arm is sort of the entry-level swing while the one-handed is the more advanced move.
However, many people who use a kettlebell never seem to progress beyond the two-handed stage. After all, the one-handed swing is a logical progression if you’re looking to do cleans, snatches, high pulls, or any number of other exercises.
If you’re just looking to get fit, though, is one better than the other?
For example, if you’re a competitive powerlifter who isn’t really looking to do much of anything beyond taking on a little better conditioning, then your needs are very different than an underweight individual desperately trying to gain some strength and maybe some muscle.
Your needs matter.
For me, my needs aren’t exactly straightforward. I’m a barbarian who is trying to lose weight, gain strength, and maybe build some muscle along the way. That means I need the best “bang for my buck,” so to speak.
It also means that I need the swing variation that will give me the most physiological adaptation, both from a muscular standpoint and from a cardiovascular one.
Let’s start with looking at the muscular aspects of the one-handed swing versus the two-handed version.
Luckily, this we have a study that’s already looked at that to some degree. In “Core Muscle Activation in One-Armed and Two-Armed Kettlebell Swing,” Anderson et al looked at how muscles respond to each variation. While I can’t read the entire paper just now, here’s an important bit from the abstract:
For the upper erector spinae, the activation of the contralateral side during 1-armed swing was 24% greater than that of the ipsilateral side during 1-armed swing (p < 0.001) and 11% greater during 2-armed swing (p = 0.026). Furthermore, the activation in 2-armed swing was 12–16% greater than for the ipsilateral side in 1-armed swing (p< 0.001). For rectus abdominis, however, 42% lower activation of the contralateral side was observed during 1-armed swing compared with ipsilateral sides during 2-armed swing (p = 0.038) and 48% compared with the ipsilateral side during 1-armed swing (p = 0.044).
Later in that same abstract:
In conclusion, performing the kettlebell swing with 1 arm resulted in greater neuromuscular activity for the contralateral side of the upper erector spinae and ipsilateral side of the rectus abdominis, and lower activation of the opposite side of the respective muscles.
So, there’s a much greater activity on the side with the weight, which isn’t overly surprising.
What is interesting are the percentages and how we can use them.
For example, they found that the contralateral side–the side with the weight–had much higher activation with the one-handed swing. While the ipsilateral side had lower, that’s less of a concern. Why? Because we’re not going to just train with a single hand. In order to maintain balance, you do swings with one hand, then switch to the other regardless.
So with so much higher neuromuscular activation, this seems like a no-brainer. One handed it is.
However, there’s a certain degree of caution we have to maintain here. After all, Anderson and company only looked at 16 subjects. That’s few enough that statistical noise could enter the discussion. It’s possible that these subjects were activating muscles in unusual ways due to somewhat unique biomechanical issues that would have been drowned out in a larger study.
I’m inclined to think that’s unlike due to the P-values for these studies being ridiculously low. That’s the measure we use to see if a difference is statistically significant, and these P-values are definitely significant, enough that I’m inclined to accept the study on face value.
Other considerations, however, are less scientific and more practical.
For example, doing one-handed swings requires an athlete to do swings with one hand, then switch and do an equal number of swings. This increases the time required for training. For some, this is probably not a huge deal, but for others, it’s a problem.
Another issue is that the one-handed swing is a bit more technical. While it’s a skill that I think every kettlebeller should learn as it’s a progression toward more technically difficult movements like the snatch and the clean, it’s still a bit trickier. That means some may well find it intimidating. It’s not difficult, but people can be freaked by the unknown.
Either of these are valid concerns that would color someone’s thinking.
For me, my swings will be shifting to one-handed swings.
While most cardiovascular studies tend to look at the two-handed swing, there are more neuromuscular requirements for the one-handed with little evidence of a reduction in cardiovascular requirements. In other words, I’ll likely get as much cardio work done, if not more since I’ll be having to switch hands and do a like number of swings.
If someone were to ask my advice, I’d tell them to start with the swing until they’re comfortable doing swing movements, then transition toward the one-handed swing. In time, use that technique to fully embrace movements like the clean and press and the snatch.
Now, that’s not to say that’s the One True Way. If you’ve read this site, you know I don’t believe in the One True Way for anything. I think there are many pathways toward success and kettlebells are no different in that regard.
However, something else I know is that after looking at the data, I can’t help but believe that two-handed swings, for me, are nothing but a waste of time.
After all, I already know how to do a one-handed swing, so why am I taking a path that uses less neuromuscular activation when I’ve got the time to do the one-handed swings in the first place?
But again, that’s just me.
Luckily, science says this is a smart approach, so that’s something to keep in mind, right?