Sports psychologists point to a few factors that make a track work:

• Tempo match — the beat fits the pace of your activity, so your movements lock onto it
• Personal meaning — a song tied to a good memory beats a "correct" workout song
• Steady rhythm — predictable beats sustain effort better than busy, shifting ones
• Lyrics — empowering words add a mental push that pure instrumentals miss

Researcher Costas Karageorghis, a leading voice on music and exercise, calls the right track a "legal drug" for performance.