Analysis Of Factors Affecting The Probability Of Finishing The Western States 100-mile Endurance Run: 2353: Board #241 May 28 2:00 PM - 3:30 PM

Wegelin, Jacob1; Hoffman, Martin D. FACSM2

Medicine & Science in Sports & Exercise:
doi: 10.1249/01.MSS.0000355518.30915.22
D-39 Free Communication/Poster - Ultra Endurance: MAY 28, 2009 1:00 PM - 6:00 PM ROOM: Hall 4F
Author Information

1Virginia Commonwealth University, Richmond, VA. 2University of California Davis Medical Center and VA Northern California Health Care System, Sacramento, CA.


(No relationships reported)

PURPOSE: Determine factors associated with finishing the Western States 100-Mile Endurance Run (WSER).

METHODS: Name, age, sex and finish or drop-out information was obtained for each runner starting the WSER from 1986 through 2007. Generalized linear mixed-effects models were computed to assess the degree to which the probability of a starter finishing a race was related to starter's sex, age, previous WSER experience, and to ambient race day temperature. Separate relationships between age and probability of finishing were computed in the lower quartile (18-38 years), interquartile (38-50 years) and upper quartile (>50 years). WSER experience was categorized as never previously started, started in the past and finished each run started, started in the past and finished at least once and dropped out at least once, and started in the past and never finished.

RESULTS: There were a total of 8282 starts and 5276 finishes from 1986 through 2007. Yearly finish rates ranged from 51% to 80%. There was no effect of age across 18-38 years, but from 38-50 years an increase in age was associated with decreased probability of finishing and the association was stronger for >50 years (both p<0.001). Specifically, men were 46% more likely to finish at age 38 than 50, and 6 times more likely to finish at age 50 than 72. Men and women 18-38 years of age had no difference in probability of finishing, but women's probability of finishing decreased more quickly than men's across ages 38-50 (p=0.01). Specifically, 50 year old men were 70% more likely to finish than 50 year old women. Over age 50, the decrease was parallel for men and women. New starters since 1986, and those who had finished every race they started since 1986, were 28% more likely (p<0.001) to finish than those who had ever dropped out of the race since 1986. Increased ambient temperature was associated with a decreased probability (p=0.026) of finishing. Starters who had previously dropped out of the race were more likely (p=0.036) to drop out in high temperatures than those who either had always finished or had never started since 1986.

CONCLUSIONS: Factors adversely associated with finishing the WSER include increasing age, being female >38 years of age, having previously dropped out of the race, and higher ambient temperatures.

Supported by the Ultra-Endurance Exercise Research Foundation

©2009The American College of Sports Medicine