Efficacy of oral versus intravenous hypertonic saline in runners with hyponatremia.

Objectives: To determine more conclusively whether intravenous (IV) administration of 3% saline is more efficacious than oral administration in reversing below normal blood sodium concentrations in runners with biochemical hyponatremia.

Design: Randomized controlled trial.

Methods: 26 hyponatremic race finishers participating in the 161-km Western States Endurance Run were randomized to receive either an oral (n=11) or IV (n=15) 100mL bolus of 3% saline.

Characteristics of 161-km ultramarathon finishers developing exercise-associated hyponatremia.

This study sought to identify runner characteristics or symptoms that could distinguish those finishers developing exercise-associated hyponatremia (EAH) from those not developing EAH in a 161-km ultramarathon. Of 310 finishers, 207 (67%) underwent postrace blood studies. Twelve (6%) finishers had EAH (blood sodium range 131-134 mmol/L).

The effect of physiology and hydration beliefs on race behavior and postrace sodium in 161-km ultramarathon finishers.

Purpose: To determine if beliefs about physiology and rehydration affect ultramarathon runners' hydration behaviors or if these beliefs increase the risk for exercise-associated hyponatremia (EAH).

Methods: Participants of the 2011 161-km Western States Endurance Run completed a prerace questionnaire, prerace and postrace body-mass measurements, and postrace assessment of serum sodium ([Na⁺]).

Results: Of 310 finishers, 309 (99.

Urine dipstick analysis for identification of runners susceptible to acute kidney injury following an ultramarathon.

This study examined whether urine dipstick testing might be useful to predict the development of acute kidney injury after an ultramarathon. Participants in the 2011 161-km Western States Endurance Run underwent post-race blood and urine dipstick analyses. Of the 310 race finishers, post-race urine dipstick testing was completed on 152 (49%) and post-race blood also was obtained from 150 of those runners.

Demographic characteristics of 161-km ultramarathon runners.

Despite considerable recent growth in ultramarathon running, little is known about the characteristics of the participants. This work documents demographic characteristics of 161-km ultramarathoners. Surveys were completed by 489 of 674 runners entered in two of the largest 161-km ultramarathons in North America in 2009.

Factors related to successful completion of a 161-km ultramarathon.

Purpose: Despite increased 161-km ultramarathon participation in recent years, little is known about those who pursue such an activity. This study surveyed entrants in two of the largest 161-km trail ultramarathon runs in North America to explore demographic characteristics and issues that affected race performance.

Methods: All entries of the 2009 Western States Endurance Run and the Vermont 100 Endurance Race were invited to complete a postrace questionnaire.