Hydration strategies, weight change and performance in a 161 km ultramarathon.

To examine controversies about hydration strategies, participants (383 starters) of a 161 km ultramarathon (maximum temperature 39.0°C) underwent body weight measurements before, during and after the race; and completed a post-race questionnaire on drinking strategies and sodium supplementation use during 4 race segments. Drinking to thirst was the most common (p < 0.

Longitudinal assessment of the effect of age and experience on performance in 161-km ultramarathons.

Purpose: This work longitudinally assesses the influence of aging and experience on time to complete 161-km ultramarathons.

Methods: From 29,331 finishes by 4066 runners who had completed 3 or more 161-km ultramarathons in North America from 1974 through 2010, independent cohorts of men (n = 3,092), women (n = 717), and top-performing men (n = 257) based on age-group finish place were identified. Linear mixed-effects regression was used to assess the effects of aging and previous 161-km finish number on finish time adjusted for the random effects of runner, event, and year.

Pacing by winners of a 161-km mountain ultramarathon.

Purpose: To examine pacing among the most successful runners in the 161-km Western States Endurance Run (WSER) to determine if variations in segmental speed relate to performance, ambient temperature, and calendar year.

Methods: Segmental speed and coefficient of variation (CV) in speed were analyzed for 10 race segments of 24 races from 1985 through 2013.

Results: Segmental speeds did not differ between the eventual winners and lead runners and only differed between the 1st and 2nd finishers in the 2nd half of the race.

Health and exercise-related medical issues among 1,212 ultramarathon runners: baseline findings from the Ultrarunners Longitudinal TRAcking (ULTRA) Study.

Regular exercise is associated with substantial health benefits; however, little is known about the health impact of extreme levels of exercise. This study examined the prevalence of chronic diseases, health-care utilization, and risk factors for exercise-related injuries among ultramarathon runners. Retrospective, self-reported enrollment data from an ongoing longitudinal observational study of 1,212 active ultramarathon runners were analyzed.

Body mass index and its correlates in 1,212 ultramarathon runners: baseline findings from the ULTRA study.

Background: Little is known about the sociodemographics and lifestyle behaviors of ultramarathon runners, and the effects of these characteristics on body weight and body mass index (BMI).

Methods: We cross-sectionally analyzed baseline data of 1212 ultramarathoners on sociodemographics, lifestyle behaviors and BMI from the initial 12-month enrollment period in a longitudinal observational study.

Results: The ultramarathoners were mostly middle-aged men who were more educated, more likely to be in a stable relationship, and more likely to use over-the-counter vitamins/supplements than the general population.

The need for salt: does a relationship exist between cystic fibrosis and exercise-associated hyponatremia?

Salt replacement is often recommended to prevent exercise-associated hyponatremia (EAH) despite a lack of evidence to support such practice. Exercise-associated hyponatremia is known to be a complex process resulting from the interplay of hydration, arginine vasopressin, and sodium balance. Although evidence suggests overhydration is the dominant pathophysiologic factor in most cases, the contributions of sweat sodium losses remain unclear.

Anomalous vertebral artery injured during anterior cervical discectomy: a case report.

Study Design: Case report.

Objective: To describe treatment and injury prevention from discectomy with a newly described vertebral artery anomaly.

Summary Of Background Data: Cervical segment vertebral artery (VA) anomalies of various types are described with the least common type involving erosion into the vertebral body medial to the uncinate process.

Insulin and IGFs enhance hepatocyte differentiation from human embryonic stem cells via the PI3K/AKT pathway.

Human embryonic stem cells (hESCs) can be progressively differentiated into definitive endoderm (DE), hepatic progenitors, and hepatocytes, and thus provide an excellent model system for the mechanistic study of hepatocyte differentiation, which is currently poorly understood. Here, we found that insulin enhanced hepatocyte differentiation from hESC-derived DE. Insulin activated the PI3K/AKT pathway, but not the mitogen-activated protein kinase pathway in the DE cells, and inhibition of the PI3K/AKT pathways by inhibitors markedly inhibited hepatocyte differentiation.

Physiological responses to body weight--supported treadmill exercise in healthy adults.

Objective: To determine whether the relationships of heart rate, rating of perceived exertion (RPE), and ground reaction forces (GRFs) with oxygen consumption rate (Vo(2)) during treadmill exercise are altered by partial body weight support (BWS) via lower-body positive pressure.

Design: Repeated-measures design.

Setting: Exercise physiology laboratory.

Historical analysis of participation in 161 km ultramarathons in North America.

Participation trends in 100 m (161 km) ultramarathon running competitions in North America were examined from race results from 1977 through 2008. A total of 32, 352 finishes accounted for by 9815 unique individuals were identified. The annual number of races and number of finishes increased exponentially over the study period.

Body composition of 161-km ultramarathoners.

This study compares body composition characteristics with performance among participants in a 161-km trail ultramarathon. Height, mass, and percent body fat from bioimpedance spectroscopy were measured on 72 starters (17 women, 55 men). Correlation analyses were used to compare body characteristics with finish time, and unpaired t-tests were used to compare characteristics of finishers with non-finishers.

The Western States 100-Mile Endurance Run: participation and performance trends.

Purpose: Examine changes in demographics of participants and performance trends at the Western States 100-Mile Endurance Run (WSER) since its inception in 1974.

Methods: Name, age, sex, and finish information was obtained on runners in the WSER from 1974 to 2007. Linear regression analyses, ANOVA, and t-tests were used to examine participation and performance trends.

Ultramarathon trail running comparison of performance-matched men and women.

Purpose: To determine whether women matched with men for age and performance in a 50-km trail ultramarathon performed differently than the men in 80- and 161-km trail ultramarathons.

Methods: Race results from 1990 to 2007 were examined to identify finishers of the Way Too Cool 50-km Race, the American River 80-km Race, and the 161-km Western States Endurance Run in the same year. Matching of women with men for age (mean difference = 1 yr) and 50-km finish time (mean absolute variation = 1.

Pain perception after running a 100-mile ultramarathon.

Objective: To determine if pain perception is affected by an extreme bout of exercise that causes ongoing exercise-related pain.

Design: Repeated-measures design.

Setting: Pre-race registration area and finish area of an endurance race.

The utility of sonography for the triage of blunt abdominal trauma patients to exploratory laparotomy.

Objective: The purpose of this study was to assess the utility of focused abdominal sonography for trauma (FAST) in the triage of hypotensive and normotensive blunt abdominal trauma patients to exploratory laparotomy.

Materials And Methods: Data entered in a trauma registry database were retrospectively reviewed and were correlated with medical records, radiology reports, and surgical laparotomy reports. In the setting of blunt abdominal trauma, hypotensive patients were compared with normotensive patients who underwent FAST.

Effect of blood transfusion on outcome after major burn injury: a multicenter study.

Objective: To delineate blood transfusion practices and outcomes in patients with major burn injury.

Context: Patients with major burn injury frequently require multiple blood transfusions; however, the effect of blood transfusion after major burn injury has had limited study.

Design: Multicenter retrospective cohort analysis.

Evaluation of a theoretical model to quantify the sources of metabolic cost in walking.

Objective: To evaluate the validity of a theoretical model of walking in which the oxygen uptake (V(O2)) is described as a function of speed by an equation in the form y = ax + b, with constant a representing the metabolic cost for performing the walking movement, and constant b representing the sum of the metabolic costs for basal metabolism and maintaining balance and posture.

Design: Repeated-measures analysis of variance was used to analyze our theoretical model. In a human exercise research laboratory, 12 healthy male subjects walked on a level treadmill at speeds of 0.

Visceral intestinal Buerger's disease.

Buerger's disease is a non-arteriosclerotic, segmental, progressive, inflammatory vaso-occlusive disease of unknown etiology. Buerger's disease occurs almost exclusively in susceptible young men who are habitual tobacco users; usually with onset of symptoms before the age of 40 years. Buerger's disease affects both arteries and veins of principally lower and upper limbs and, rarely, of the viscera.