Music and running
Evidence: moderate
Music is a real but small aid, and the effect is mostly on how the run feels rather than how fast you go. It lowers perceived effort and lifts mood at easy and moderate paces, and largely stops working once you are above threshold. Useful for easy volume and motivation, not a meaningful enhancer for hard racing, and a genuine safety and rules issue near traffic and in competition.
Pooled across 139 studies, music produces a small benefit to performance, a modest reduction in perceived exertion, and its largest effect on how the effort feels (Terry et al. 2020). The effect on heart rate is negligible, which is the tell: music changes perception and mood, not the underlying physiology.
That perceptual lever has a ceiling. Music lowers perceived effort at low-to-moderate intensities by roughly a tenth, but the effect fades above the anaerobic threshold, where the body’s own signals crowd out the distraction (Karageorghis & Priest 2011-2012). So music helps most exactly where running is already easy, on recovery and steady runs, and least in the hard efforts that decide races. Matching cadence to a track’s tempo (synchronous music) squeezes out a little more, including a lower oxygen cost, and faster tempos help more than slow ones. The mechanism is dissociation, pulling attention away from fatigue, which connects to the attentional strategies in mental training.
Music before a run is a separate, modest tool: it raises power output and lifts pre-exercise mood, useful as part of a warm-up, though it does not carry over to lower perceived effort once running (Delleli et al. 2023).
Safety and rules
Two caveats are not marketing fine print. Headphones reduce awareness of traffic and approaching hazards, and a case series links pedestrian headphone use to injury and death; it cannot quantify the risk, but the mechanism is plausible enough to warrant caution near roads, with bone-conduction or open-ear designs a sensible compromise (Lichenstein et al. 2012). In competition, many governing bodies restrict audio devices, banning them for athletes competing for awards, medals or prize money even where recreational runners may use them (USATF and World Athletics).
The honest summary: a worthwhile motivator for easy and steady running and a mood-lifter on a dull day, with effects that are small, perceptual, and concentrated below race intensity. It is not a substitute for fitness, and how much any runner gets from it varies (individual variation).