Why does Naruto run with his arms back? The physics behind it, explained

The Naruto fanbase is infamous for having discussions about various elements in the series. One such topic that plenty of anime and non-anime fans have discussed is the way Naruto runs in the series. Pretty much all shinobis run in a similar manner, and there is an explanation for it.

We can understand running from a physics standpoint and explain the mechanism for the way these characters run in the series. Additionally, we can also speculate on other reasons for it from a production standpoint.

Popular YouTube channel Because Science conducted a test in which they spoke about the shinobi running in depth. This article will refer to data used in the aforementioned video to help readers understand the science behind the protagonist’s method of running in the series.

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Understanding the effects of drag on the Naruto run

Understanding why the protagonist and other shinobis ran a particular way (Image via Studio Pierrot)

Drag is a very important term in fluid dynamics that will help us understand the reason for Naruto’s alteration in the way he runs; it is a force that acts in a direction opposite to the relative motion of the object in a fluid. This is a big reason why airplanes, cars, and bikes are shaped in a manner to mitigate drag, by reducing drag, the object can travel faster and utilize energy more efficiently. This applies to running as well. The formula to calculate the force of drag on any object is as mentioned below:

D = Cd×A×0.5×ρ×V2

In the abovementioned formula, Cd is the coefficient of drag, A is the area on which drag is acting, ρ is the density of the surrounding fluid, and V is the velocity of the object on which drag is acting. Based on this formula, it is understood that drag is directly proportional to two main variables -- exposed area and the velocity of the moving object. In fact, drag increases exponentially as the speed of the object increases.

The exposed area is significantly lower for the protagonist compared to a regular runner (Image via Studio Pierrot and Freepik)

Essentially, what Naruto Uzumaki and other shinobis are doing is reducing the drag by tucking in slightly and pushing their hands behind. This drastically reduces the area which in turn reduces the drag acting on them. This isn’t a practical way of running and therefore, works only in anime. By leaning forward and dropping their hands behind, the movement is not efficient and can impede balance since they’re leaning over their center of gravity.

Now that we have explained the physics behind the Naruto run, let’s understand one other possible reason for the way most shinobis run in the series.

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Another possible reason for the Naruto run

It is noteworthy to mention that the series didn’t really provide an explanation for this run. However, if we take a look at this from a production standpoint, this is certainly easier to animate compared to the way humans actually run. In this method, the hands are behind, which means, only the legs need to be animated.

Given the sheer volume of fights in the series, animating the arm swing with every stride they take would be extremely tedious. This could be another reason why Masashi Kishimoto made most characters run in the Naruto series in a very particular manner.

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