Music makes jogging easier. Lots of runners say so, but now a German researcher at Dortmund's Technical University has proved it and comes up with the reason.
Yves Cloos splits the effects of music on sport into three factors. Music boosts endurance, although only in the mid-range of strenuous activity and not during all-out exertion.
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Music alters how exertion is experienced. Cloos has discovered that listening to music leads joggers to underestimate their level of exertion. And finally runners simply feel better when they jog to music.
Based on a survey of more than 500 people, along with experiments on runners and cyclists, he discovered that those taking exercise while listening to music felt that they had been active for less time than was the case without music.
It remains unclear precisely why music has these three effects, although a likely explanation is that runners have their attention distracted and they no longer notice the passage of time, Cloos says.
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He denies that this could be a reason to fear that people taking exercise could overextend themselves. As soon as joggers begin to exert themselves more strenuously and approach their limits, their pain threshold takes over.
"There is no danger of over-exertion," he says.
The obvious question is, what type of music should the jogger choose.
"People should ask themselves how motivational they find the rhythm or the melody, and to what extent the music chosen supports their movements. Do I run faster or slower?" Cloos says.
Joggers are frequently told to take into consideration the beats per minute in the music, with rates between 120 and 140 suitable for joggers.
But the researcher is sceptical, pointing out that the jogger can also run at two beats per pace.
"It's fine as long as I have the impression that the music fits," he says
Melody is also important. "The better I know the song the more attractive it is. A song in a cheerful major key does not necessarily motivate better than one in a moody minor," Cloos says.
The words can also have an effect through causing associations, although they tend to be pushed into the background by rhythm and melody.
And variety is essential.
"Joggers get used to their songs. They then lose their positive effect," Cloos says.