Jess McClain, the American course-record holder from the 2026 Boston Marathon, relies on a carefully curated 33-song playlist to fuel her marathon training. The playlist serves as more than background noise—it functions as a performance tool that helps her maintain rhythm, pace, and mental focus during long runs.

McClain's approach aligns with research showing music's measurable effects on endurance exercise. Studies consistently demonstrate that tempo and beat synchronization can reduce perceived exertion, improve running economy, and enhance motivation during aerobic workouts. The strategic use of music can lower heart rate variability at given intensities, allowing runners to work more efficiently.

For marathoners, playlist construction matters. Tempo matching becomes critical. Songs with beats per minute (BPM) between 120 and 140 typically align with sustainable marathon paces, helping runners unconsciously maintain goal speed without constant watch-checking. McClain's 33-song selection likely balances this range to support different training phases—easier base-building runs versus tempo work and race-pace efforts.

Beyond the biomechanics, music provides psychological benefits marathoners need. Long training runs demand mental resilience. A familiar playlist creates structure within the monotony of distance running. Songs trigger positive associations and emotional responses that combat the mental fatigue that accumulates over 18-22 week training cycles.

McClain's dedication to playlist curation reflects how elite distance runners optimize every training variable. While genetics and structured coaching form the foundation, marginal gains compound. A well-designed playlist that maintains cadence, reduces mental strain, and sustains motivation across months of training represents the kind of detail-oriented approach that separates elite marathoners from recreational runners.

The Boston Marathon course record holder treats music as equipment, not entertainment. For anyone training for a marathon, this underscores an overlooked truth: what you listen to during training