Physiologic alterations and predictors of performance in a 160-km ultramarathon.
Extreme endurance running has become a popular endeavor amongst elite athletes and novices alike, with over 750 annual ultra endurance events. These competitions are 160 km (100mile) long and it is not uncommon for over half of all competitors to fail to finish. Even healthy asymptomatic individuals demonstrate impaired cerebral blood flow, renal insufficiency, severe electrolyte imbalances and acute cardiovascular impairment during these competitions.
The authors of this study hoped to describe physiologic alterations in runners competing in these endurance events and determine the utility of blood pressure and weight assessment in runner performance. This study looked at 91 participants in a specific 100 mile race. One of the most interesting findings was that greater intracompetition weight loss was not associated with impaired performance but may actually be associated with better performance. Not only did athletes who lost >5% prerace weight have a better finish rate (87%) but they also had faster times at 80km and 160km, than participants who lost less weight. It was also noted that the presence of a narrow pulse pressure (<25mmHg) at 80km mark suggested increased likelihood of failure to finish and this could be a marker of runner fatigue. > From: Landman et al., Clin J Sport Med 22 (2012) 146-151. All rights reserved Lippincott Williams & Wilkins.
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