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Martin D. Hoffman

Participation in ultraendurance sports has been increasing in recent years. This participation growth has been associated with an increase in research focused on such events. While the total amount of research related to these sports remains relatively small compared with other sports, the research growth is encouraging. New sources for research funding for ultraendurance sports should advance the science. In addition to continued opportunities with observational studies, promising areas of investigation remain for experimental studies and research that uses ultraendurance-sport environments as models for studies relevant to wider populations. Insight into the breadth of research opportunities in ultraendurance sports can be gained by reviewing the abstracts published online in the International Journal of Sports Physiology and Performance from the annual Medicine & Science in Ultra-Endurance Sports Conference that took place this year in Chamonix, France.

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Martin D. Hoffman

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. Mean CV in speed was lower (P < .01) for the winners (12%) than for the other top-5 finishers (14–15%). CV in speed was related (r = .80, P = .006) to finish time for the fastest 10 finish times at the WSER. Multiple linearregression analysis revealed mean CV in speed for the top-5 runners to be related to maximum ambient temperature (coefficient =.14, P < .05) and calendar year (coefficient = –.086, P = .034).

Conclusions:

Mountain trail running is characterized by wide variations in speed, but the fastest times are achieved when speed fluctuations are limited. This is generally accomplished by the winners remaining relatively close behind the lead runners before taking the lead in the middle half of the race, and then avoiding slowing as much as the other top runners in the latter race stages. Variations in speed increase with high ambient temperatures, and the small decrease in segmental speed variability among top runners across the nearly 30 y of this study suggests that the best runners have improved at pacing this race.

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Martin D. Hoffman and Kevin Fogard

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.

Results:

There were 500 respondents among the 701 race entries (71.3% response). Finish time was found to have a significant (P <.01) negative association with training volume and was generally directly associated with body mass index. Among nonfinishers, the primary reason for dropping out was nausea and/or vomiting (23.0%). Finishers compared with nonfinishers were more likely (P <.02) to report blisters (40.1% vs 17.3%), muscle pain (36.5% vs 20.1%), and exhaustion (23.1% vs 13.7%) as adversely affecting race performance, but nausea and/or vomiting was similar between groups (36.8% vs 39.6%). Nausea and/or vomiting was no more common among those using nonsteroidal anti-infammatory drugs (NS AIDs), those participating in the event with higher ambient temperatures, those with a lower training volume, or those with less experience at finishing 161-km races. Overall use of NSAIDs was high, and greater (P = .006) among finishers (60.5%) than nonfinishers (46.4%).

Conclusions:

From this study, we conclude that primary performance-limiting issues in 161 -km ultramarathons include nausea and/or vomiting, blisters, and muscle pain, and there is a disturbingly high use of NSAIDs in these events.

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Martin D. Hoffman and Carol A. Parise

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.

Results:

Men and women up to 38 y of age slowed by 0.05–0.06 h/y with advancing age. Men slowed 0.17 h/y from 38 through 50 y and 0.23 h/y after 50 y. Women slowed 0.20–0.23 h/y with advancing age from 38 y. Top-performing men under 38 y did not slow with increasing age but slowed by 0.26 and 0.39 h/y from 38 through 50 y and after 50 y, respectively. Finish number was inversely associated with finish time for all 3 cohorts. A 10th or higher finish was 1.3, 1.7, and almost 3 h faster than a first finish for men, women, and top-performing men, respectively.

Conclusions:

High-level performances in 161-km ultramarathoners can be sustained late into the 4th decade of life, but subsequent aging is associated with declines in performance. Nevertheless, the adverse effects of aging on performance can be offset by greater experience in these events.

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Martin D. Hoffman and Thomas M. Myers

Symptomatic exercise-associated hyponatremia (EAH) is known to be a potential complication from overhydration during exercise, but there remains a general belief that sodium supplementation will prevent EAH. We present a case in which a runner with a prior history of EAH consulted a sports nutritionist who advised him to consume considerable supplemental sodium, which did not prevent him from developing symptomatic EAH during a subsequent long run. Emergency medical services were requested for this runner shortly after he finished a 17-hr, 72-km run and hike in Grand Canyon National Park during which he reported having consumed 9.2–10.6 L of water and >6,500 mg of sodium. First responders determined his serum sodium concentration with point-of-care testing was 122 mEq/L. His hyponatremia was documented to have improved from field treatment with an oral hypertonic solution of 800 mg of sodium in 200 ml of water, and it improved further after significant aquaresis despite in-hospital treatment with isotonic fluids (lactated Ringer’s). He was discharged about 5 hr after admission in good condition. This case demonstrates that while oral sodium supplementation does not necessarily prevent symptomatic EAH associated with overhydration, early recognition and field management with oral hypertonic saline in combination with fluid restriction can be effective treatment for mild EAH. There continues to be a lack of universal understanding of the underlying pathophysiology and appropriate hospital management of EAH.

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Carol A. Parise and Martin D. Hoffman

Background:

Even pacing has been recommended for optimal performances in running distances up to 100 km. Trail ultramarathons traverse varied terrain, which does not allow for even pacing.

Purpose:

This study examined differences in how runners of various abilities paced their efforts in the Western States Endurance Run (WSER), a 161 km trail ultramarathon in North America, under hot vs cooler temperatures.

Method:

Temperatures in 2006 (hot) and 2007 (cooler) ranged from 7-38°C and 2-30°C, respectively. Arrival times at 13 checkpoints were recorded for 50 runners who finished the race in both years. After stratification into three groups based on finish time in 2007 (<22, 22-24, 24-30 h), paired t tests were used to compare the difference in pace across checkpoints between the years within each group. The χ2 test was used to compare differences between the groups on the number of segments run slower in the hot vs cooler years.

Results:

For all groups, mean pace across the entire 161 km race was slower in 2006 than in 2007 (9:23 ± 1:13 min/km vs 8:42 ± 1:15 min/km, P < .001) and the pace was slower from the start of the race when temperatures were still relatively cool. Overall, the <22 h cohort ran slower in 2006 than 2007 over 12 of the 14 segments examined, the 22–24 h cohort was slower across 10 of the segments, and the >24 h cohort was slower across only 6 of the segments χ2 2 = 6.00, P = .050). Comparable pacing between the 2 y corresponded with onset of nighttime and cooling temperatures.

Conclusions:

Extreme heat impairs all runners’ ability to perform in 161 km ultramarathons, but faster runners are at a greater disadvantage compared with slower competitors because they complete a greater proportion of the race in the hotter conditions.

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Martin D. Hoffman, Linjun Chen and Eswar Krishnan

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. They appear to gain less body weight with advancing age than the general population. Factors with the greatest effect on current BMI were BMI at 25 years of age and sex, which explained 48% and 3% of the variance. Negligible, but statistically significant direct relationships, with BMI were observed for age, work hours per week, television watching hours per week, and composite fat consumption frequency score. Negligible, but statistically significant inverse relationships, with BMI were observed for running distance during the prior year, and composite fruit and vegetable consumption frequency score.

Conclusions:

While lifestyle decisions were found to impact BMI within this group of ultramarathoners, BMI at age 25 was the strongest predictor of current BMI.

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Martin D. Hoffman, Philip S. Clifford and Frank Bender

This investigation examined the adjustments made in cycle rate and length to velocity changes during roller skiing with the double pole (DP), kick double pole (KD), and VI skate (VS) techniques. Eight cross-country ski racers roller skied with each technique on a flat track at submaximal and maximal velocities while being videotaped from a lateral view. Increases in submaximal velocities were associated with increases in cycle rate and cycle length for KD and VS but only with increases in cycle rate for DP. Maximal sprint velocities were approximately 7% lower (p < .01) for KD than for DP and VS and were associated with increases (p < .01) in cycle rate for each technique combined with decreases (p < .01) in cycle length for DP and VS. The findings indicate that there are differences among techniques in the manner in which cycle rate and length are adjusted to change submaximal velocity, but each technique relies upon an increase in cycle rate to achieve maximal velocity.

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Kristin J. Stuempfle, Martin D. Hoffman and Tamara Hew-Butler

Context:

Gastrointestinal (GI) distress is common during ultrarunning.

Purpose:

To determine if race diet is related to GI distress in a 161-km ultramarathon.

Methods:

Fifteen (10 male, 5 female) consenting runners in the Javelina Jundred (6.5 loops on a desert trail) participated. Body mass was measured immediately prerace and after each loop. Runners reported if they had nausea, vomiting, abdominal cramps, and/or diarrhea after each loop. Subjects were interviewed after each loop to record food, fluid, and electrolyte consumption. Race diets were analyzed using Nutritionist Pro.

Results:

Nine (8 male, 1 female) of 15 runners experienced GI distress including nausea (89%), abdominal cramps (44%), diarrhea (44%), and vomiting (22%). Fluid consumption rate was higher (p = .001) in runners without GI distress (10.9 ± 3.2 ml · kg−1 · hr−1) than in those with GI distress (5.9 ± 1.6 ml · kg−1 · hr−1). Runners without GI distress consumed a higher percentage fat (p = .03) than runners with GI distress (16.5 ± 2.6 vs. 11.1 ± 5.0). In addition, fat intake rate was higher (p = .01) in runners without GI distress (0.06 ± 0.03 g · kg−1 · hr−1) than in runners with GI distress (0.03 ± 0.01 g · kg−1 · hr−1). Lower fluid and fat intake rates were evident in those developing GI distress before the onset of symptoms.

Conclusions:

A race diet with higher percentage fat and higher intake rates of fat and fluid may protect ultramarathoners from GI distress. However, these associations do not indicate cause and effect, and factors other than race diet may have contributed to GI distress.

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Martin D. Hoffman, Kristin J. Stuempfle, Ian R. Rogers, Louise B. Weschler and Tamara Hew-Butler

Purpose:

To determine the incidence of exercise-associated hyponatremia (EAH), the associated biochemical measurements and risk factors for EAH, and whether there is an association between postrace blood sodium concentration ([Na+]) and changes in body mass among participants in the 2009 Western States Endurance Run, a 161-km mountain trail run.

Methods:

Change in body mass, postrace [Na+], and blood creatine phosphokinase (CPK) concentration, and selected runner characteristics were evaluated among consenting competitors.

Results:

Of the 47 study participants, 14 (30%) had EAH as defined by a postrace [Na+] <135 mmol/L. Postrace [Na+] and percent change in body mass were directly related (r = .30, P = .044), and 50% of those with EAH had body mass losses of 3–6%. EAH was unrelated to age, sex, finish time, or use of nonsteroidal anti-inflammatory drugs during the run, but those with EAH had completed a smaller (P = .03) number of 161-km ultramarathons. The relationship of CPK levels to postrace [Na+] did not reach statistical significance (r = –.25, P = .097).

Conclusions:

EAH was common (30%) among finishers of this 161-km ultramarathon and it was not unusual for those with EAH to be dehydrated. As such, changes in body mass should not be relied upon in the assessment for EAH during 161-km ultramarathons.