Martin D. Hoffman · The International Journal of the History of Sport 2010 · retrospective longitudinal cohort study · n=9815 individuals (32352 finishes)

Historical Analysis of Participation in 161 km Ultramarathons in North America

Cited 259 times in the scientific literature.

Level 3 - non-randomized controlled study

Non-clinical longitudinal historical database analysis (graded by design analogy, not clinical CEBM)

OpenAlex W2100643880 · doi:10.1080/09523367.2010.494385 · record verified 2026-08-31

What was done

Race results from 100-mile (161 km) ultramarathon competitions in North America were compiled from 1977 through 2008 to examine participation and demographic trends over time.

What was found

The dataset included 32,352 finishes by 9,815 unique individuals. Both the annual number of races and total finishes increased exponentially over the study period. Finishes by runners over 40 years of age rose from less than 40% prior to the mid-1980s to 65-70% since 1996. Female participation increased from virtually none in the late 1970s to nearly 20% since 2004 (p < 0.0001). The average annual number of races completed per individual rose to 1.3.

Why it matters

This study documents the multi-decade growth and demographic shifts in extreme endurance running in North America, showing substantial growth driven by older runners and women despite remaining a niche sport relative to shorter distances.

Limits

The analysis is restricted to race finishers of North American 161 km events, omitting non-finishers, shorter ultramarathon distances, international races, and underlying health or training variables.

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