Anyone who’s ever hefted a dumbbell or laced up a running shoe understands that music, on some level, makes the process more enjoyable. That’s why tunes and training are a hit combination: there are playlists, classes and even entire fledgling genres promising to help you push for the burn. Broadly speaking, there are two ways music can help you mid-workout. First, by helping you dissociate from any discomfort you’re experiencing and, second, by improving the quality of the training itself. The former seems to work especially well for long, slow efforts. “Let’s say you’re going on a run,” says Dr Matthew Stork, a research scientist who studies the effects of music on training, “and there are lots of what we call ‘interoceptive’ cues happening – your muscles are sore, your heart rate’s going up, you’re sweating, and so on. Music shifts your attentional focus away from those things, reducing your perceived exertion.” But you might not even need anything tuneful on your headphones for these effects to kick in. “The introduction of other common audio formats has really shaken up our knowledge of how we think about music and exercise,” says Dr Christopher Ballman, associate professor of kinesiology at the University of Alabama. “There are individuals now who will perform better listening to podcasts or even audio books – these help people dissociate from discomfort.” As you up the intensity, the unpleasantness becomes tougher to ignore – but here, music might help you to push through. “What we’ve found in supermaximal tests – where volunteers are basically pushing themselves as hard as they possibly can – is that power output goes up with music,” says Stork. “In those efforts, it seems to be more beneficial as a motivational tool. Think about a piece like Darude’s Sandstorm – we’ve seen that just the anticipation of the beat drop can influence how ready you are for exercise.” As for how music can actually improve your workout, improvements in technology have made this easier to quantify. “We now know that music influences not just our heart rate, blood pressure and breathing rate, but also electrical activity in the brain,” says“A good analogy might be that if you’re running and every time you get to a junction, you encounter a green light, that would be the same as working out synchronously with music – if you’re listening to music out of time, or don’t have any music at all, it’s like constantly stopping at red lights. You’re juddering along, out of pace.” For cardio-style workouts, an optimal workout tempo is 120-140BPM (beats per minute) for most people, where it’s likely to match the heart rate they experience. At the same time, at least one study suggests that we spontaneously modify our cadence to match the tempo of the music we’re listening to, suggesting that differently paced tunes might help runners or rowers change their pacing. Rhythm is also important. “A predictable, not-too-complex musical rhythm seems to work best,” says Karageorghis. “Classical music and rock, for instance, are often characterised by rallentandos and accelerandos – basically, slowing down and speeding up – which isn’t very good if you’re trying to synchronise your performance with the beat.” Rhythmic workouts, rock and classical music also share what researchers call “iconic cues”. “These are basically a way of conjuring imagery through the nature of the music,” says Karageorghis. “So if you take something like Beethoven’s Eroica Symphony, that might conjure images of transcendence and overcoming adversity – whereas a piece like Eye of the Tiger has a guitar riff that comes at you like a boxer’s jab and encourages you to match that intensity.” You’d also expect Survivor’s masterful wordplay to play a part – but the role of lyrics is one of the least well-understood elements of music’s effects. “In a study that we’ve recently completed, but not yet published, we asked volunteers to pick their favourite music for a weightlifting effort, then asked them to listen to either a regular or instrumental version,” says Ballman. “We didn’t really see any differences in actual performance, but people enjoyed the session more and were more motivated, if they were listening to the lyrical version.” “During our formative years, we tend to form quite secure bonds with certain music and lyrics that we personally find meaningful,” says Karageorghis. “And so a particular song can be very individual, but there can also be pieces of music that through peer group influence or sheer cultural impact can have a powerful bearing on our psychology. It’s really about matching the person to the situation, the intensity and the mode of exercise.” All of this brings us to the crucial point that playlists, personal trainers and spin instructors often miss: workout music works much better if you actually like it. “To get the most out of your training you need to actually like what you’re listening to,” says Ballman. “We’ve published around 15 papers now, which show that if you don’t like the music being played, you perform worse – in some cases worse than you would with no music at all.” In fact, maybe the most important thing music can do is make the entire experience of working out more enjoyable – independent of any personal bests you set or aching legs you experience. That’s crucial, because enjoying workouts might be the best way to make them a permanent part of your life. “Until fairly recently, scientists were trying to apply a form of science known as cognitivism to getting people engaged in physical activity – asking them to think about the benefits,” explains Karageorghis. “But there’s a scientific movement towards promoting hedonism as a more modern approach to getting people to habitually engage in physical activity – the core of that is fundamentally making sure they enjoy what they’re doing and music can play a huge part in that.” With this in mind, maybe the best thing any coach can do is cater to their clientele: not just to hype them up, but to keep them coming back. It’s an approach that’s paying off for a new breed of music-centric fitness classes that tailor their tunes to the work rate required. “You have to know when to go slow and when to go high,” says Sophie Ritchie, creator of ballet-inspired workout Disco Barre. “We play a mix of underground disco, house, boogie, funk, pop, Balearic, Italo and acid – if you can do it right, people forget how hard they’re working.” Other trainers take recommendations directly from their trainees. “My clients are all of a certain age and my playlists tend to be based on music from when they were younger,” says Feel Good Fitness coach Susannah Simmons. “It helps motivate them and also gets conversation going – while newer music tends to have the opposite effect. It’s important to remember it’s about them, not you.” So you just need to find a class that lets you listen to Metallica’s One and you’re sorted? Perhaps not: some research suggests that overfamiliarity can mute the buzz any one song gives you. “I look at familiarity with music as a sort of inverted-U principle,” says Stork. “You’re probably not going to get to an optimal state to work out from hearing a piece of music once or twice, but once you’ve heard something on the radio a thousand times, it’s not going to elicit the same emotional response any more. So there may be a kind of sweet spot.” There’s one final wrinkle here, which is the question of whether there are times it’s better to turn off the music – or leave the headphones at home entirely. “If your goal is to keep an easy pace or complete a recovery run, music could get in the way,” says Brady Holmer, a researcher at examine.com and sub-three-hour marathon runner. “Headphones can remove the feedback from your steps and your breathing rate, so you might not perceive effort correctly. Listening to songs that motivate you or with a tempo that’s too fast can also push you to run faster than you’d like. I save my music playlists for hard or fast workouts and listen to podcasts or audiobooks – if anything at all – for my easy runs.” For most workouts, then, keep things fairly simple: choose music you like, keep the rhythms simple and the tempo moderately high. Save a few favourite songs for tougher efforts – in theory, you’ll come to associate them with the fun and endorphin rush of a good workout. Above all, remember that maybe the most powerful thing music can do isn’t push you to do a bit better in one individual workout, but keep you coming back again and again.