Gear for Your Ear! Fast & Slow Songs Can Both Speed You Up on the First 800m of a 5K. Plus: Calm Songs Increase Vagal Tone & CNS Activity, Fast Songs Spike You Up!

One of the runners in the study (original image from Bigliassi. 2014)

Music-related interventions have been widely used in sports and exercise; and despite the fact that you've read about respective studies here at the SuppVersity before I thought the publication of a recent study from the Center of  Physical  Education  and  Sports at the State  University of Londrina was a good reason to address the issue once more.

It goes without saying that there are numerous external factors which determine the optimal workout music, as well as how and when to use it. Against that background, it should be obvious that the following study outcomes are not entitled to be "universal".
Just think about personal preferences, for example. A classic fan is probably not going to work out listening to music by Dr. Dre... well unless he's boxing, maybe! A thought that takes us to another important factor: Who knows if the same music that helps you to lift harder will also make you run longer and vice versa?

Why is this important? Well, in the study at hand, the exercise of choice was running. An exercise type the authors considered particularly fit for their study, because it's "a common physical exercise worldwide, due to its own features (low cost and availability for practice) and high aerobic benefits". Moreover, previous research has demonstrated that music can aid running by acting in parallel to exercise. It was thus logical to try to expand our still incomplete knowledge of the effects of music on exercise performance - albeit this time in a long term study with many degrees of freedom:

"Acoustic gear" - (Re-)Read my previous research summary from 2013 | go ahead

"This study was divided into 3 stages that were performed in the course of 30 weeks. In the first stage, all participants were interviewed separately before the experiment. At this time, they gave their anthropometric measures (weight and height), personal information (age, time of continuous training, number of running competitions and training volume), and answered the Eysenck personality questionnaire (EPQ), which gives possible stratifications according to personality, checking whether music could act differently in accordance with personal features."

The subjects had to select 30 motivational songs (10 – slow speed tracks, 10 medium speed tracks and 10 fast speed tracks) and the only provided information was to select songs capable of increasing their vigor and motivation to accomplish a severe aerobic physical exercise (when the number of tracks did not achieve the required number, they were asked to choose other songs to complete the playlist). The song stratification was performed initially via specific software solutions and thereafter by the examination of an expert musician.
In the second stage, all participants were called in to the laboratory, where they had to fill their questionnaires and to perform a neuroimaging test involving listening to a variety of songs. This technique was conducted to demonstrate how self-selected songs could act in emotional areas of the brain and how the subsequent activation of specific brain correlates with physiological assessments and the effectiveness of motivational music in inducing emotional consequences and downstream metabolic / ergogenic effects. All-in-all, the present study evaluated five experimental conditions:

• PM: Motivational songs, ranging from 110 – 150 bpm, applied before 5 km of running; 
• SM: Slow motivational songs, ranging from 80 – 100 bpm,applied during 5 km of running;
• FM: Fast motivational songs, ranging from 140 – 160bpm, applied during 5 km of running; 
• CS: Calm songs condition – calm songs applied after 5 km of running; 
• CO: Control condition, without intervention. 

The CO trial was considered the baseline, all other trial were compared to. The CO trial was performed in a silent environment to allow the subjects to focus exclusively on their body signals.

Figure 1: Parasympathetic tone during recovery (in min on x-axes) after control trial (no music) vs. calm music (left) and motivational music (left | Bigliassi. 2014)..

As you can see the 15 amateur runners (24.87 ± 2.47 years;78.87 ± 10.57 kg; 178 ± 07 cm; 24.92 ± 2.79 kg/m²; 4.85 ± 1.85 years of training; 7 ± 3.49 weekly training hours; 5.67 ± 2.85 competitions) had a significantly reduced parasympathetic tone during recovery, when they trained with motivational music (low parasympathetic tone = "spiked up").

Slow or fast? Does it matter or is it just about music in general?

The calm music (Figure 1; left), on the other hand, led to an increase in parasympathetic tone, as you would expect to see it in someone who meditates or "chills" as the kids like to call it ;-) Now that sounds great for weed-heads, but from a performance perspective it was obviously as detrimental - interestingly, though, not much more detrimental than not listening to music at all.

Figure 2: Effects of control (CO), motivational (PM), slow (SM), fast (FM) and calm (CS) music / songs on fatigue, tension, vigor, and 5k times (in s) - the effects are visible, but not significant (Bigliassi. 2014).

The most important and yet unquestionably somewhat disappointing observation Bigliassi et al. made is however the statistical non-significance of the the visible time-differences in Figure 2. 

If we investigate, why the visible advantage was "no advantage" in the strict sense (i.e. it was statistically non-significant), we will obviously get back to what I said initially: Inter-individual differences and preferences loom too large to make any generalizable recommendations with respect to the optimal workout music.
References:

• Bigliassi, Marcelo; León-Domínguez, Umberto; Buzzachera, Cosme F.; Barreto-Silva, Vinícius; Altimari, Leandro R. "HOW DOES MUSIC AID 5 KM OF RUNNING?" Journal of Strength & Conditioning Research: Post Acceptance: July 15, 2014.