Shriek 2: New findings on the effects of grunting using martial arts

I broached the subject of whether grunting (read: shrieking) while striking a tennis ball negatively affected the opponent’s reaction time.

In short, it did, à la the first manuscript to address this issue (Sennett and Kingstone, 2010).  One major point that was discussed involved whether grunting was simple distraction versus an audio overlay.  Elaborating:

  • Simple distraction – where the grunting noise directly detracts from the opponent’s ability to concentrate and track/predict ball trajectory.
  • Audio overlay – where the grunting noise is too loud for the opponent to hear the ball being struck, thereby removing audio-spatial information which would allow the opponent to better track/predict ball trajectory.

If after “audio overlay” you thought: “I’M BATMAN” with Christian Bale-like severity because you were convinced you could echolocate like a bat, close enough.  It works in a similar fashion.  If you are a non-believer in the importance of audio cues in tennis, don earplugs and belligerently challenge your most reviled opponent.  Report the score you lost by in the comments section below.

Keep the ideas of simple distraction and audio overlay in your mind, as we will revisit them in a moment.

What we now know about grunting

Fast forward to today.  We now have some evidence for both the positive and negative effects of grunting.  It can:

  • Increase the force and velocity of forehands and serves.
  • Straight up distract the opponent.  A newer study reports that Maria Sharapova’s grunt wreaks mild havoc on an opponent’s judgment of her service velocities.

Now, the most recent Sinnett, Maglinti and Kingstone (2018) study actually challenges the audio overlay theory directly, providing analyses through not the sport of tennis, but of mixed martial arts (MMA).

Why MMA?  You might ask.  Let’s delve into their violence laden study to find out.

The new findings

The dynamic trio report that in folks who are MMA competent, grunting increased the force of the kick.  This agrees with the evidence we now have that grunting increases the forces/velocities of serves and forehands.

Unfortunately, their study also found grunting distracted opponents from being able to best judge whether a kick was being aimed high or low, leading to fewer study participant payouts due to deaths.

I kid, it was probably simulated.

This then argues in favor of grunting being a pure distraction, as there is no equivalent of an audio overlay in an individual trying to kick you.  And this, is the reason they chose to utilize MMA as the sport through which to argue this concept.

Sadly, this leaves the issue of grunting as clear as a Louisiana bayou.  Because as the trio note in their study, this begs the question of whether grunting can be considered cheating or not.  On the one hand, there is clear evidence for grunting increasing stroke force/velocities but on the other, evidence for distraction.  One then cannot help but take a step further and wonder whether sex-based differences in grunting and distraction also exist.  Thoughts?

Left: increased serve velocity in a grunting bi-pedal canine. Note significantly (p < 0.001) larger semi-circumferential action markings directed toward the opponent as compared with follow through.  

Right: post opponent grunting effects in a bi-pedal canine as evidenced by decreased pixellation + loss of accoutrement.  Note equivalent non-significantly different tri-directional semi-circumferential action markings.


Other types of cheating: Regardless of where you fall on the grunting debate, this certainly has to be cheating.

1 thought on “Shriek 2: New findings on the effects of grunting using martial arts

Comments are closed.

%d bloggers like this:
search previous next tag category expand menu location phone mail time cart zoom edit close