The community suggests that there is no strict or universal minimum duration for a run to be beneficial, as consistency and total weekly volume are far more decisive than the duration of a single session.

noli's read

Current science, notably through studies on metabolic and cardiovascular health (cited in JAMA or by WHO guidelines), confirms that the benefits of exercise are cumulative, rendering the idea of a minimum threshold for general health arbitrary. For running performance, research on exercise physiology (specifically work on mitochondrial adaptation) suggests that longer durations (45-60 min) optimize certain hormonal and enzymatic mechanisms, though this remains a matter of efficiency rather than a binary effective/ineffective distinction. The idea of a 45-minute threshold for 'Zone 2' is an extrapolation from cycling physiology and lacks direct evidence for the amateur runner. Evidence based on accelerometry data indicates that there is no critical threshold, contradicting older recommendations that required 10-minute blocks. The community is converging toward a pragmatic approach: avoid analysis paralysis and prioritize regularity over realistic durations rather than seeking a hypothetical physiological minimum.

the sources

1. 1r/AdvancedRunning