Abstract
Introduction
The primary aim of the study was to compare select training and health characteristics between ultramarathon and shorter distance runners participating in a trail race series.
Methods
A questionnaire was sent to all participants who signed up for a trail race series, including distances of 10 km, half marathon, 50 km, 80.5 km (50 mi), and 100 km. There were 59 participants (27 ultramarathoners and 32 half marathon/10-km runners) who completed the questionnaire. We compared the training and health characteristics between groups using t tests and Fisher exact tests.
Results
There were no significant differences in reported history of stress fracture (15% vs 9%; P=0.70) or sleep quality scores (4.4 vs 5.5; P=0.15) between the ultramarathon and half marathon/10-km groups. Over half of both groups reported trying to change body weight to improve performance, without significant differences between groups (65% vs 53%; P=0.42). A significantly greater proportion of the ultramarathoners reported an episode of binge eating in the 4 wk preceding the race (38% vs 3%; P=0.001).
Conclusions
Despite differences in training volume, we did not find different injury, sleep, and nutrition data between the ultramarathoners and half marathon/10-km runners, with the exception of more ultramarathoners reporting binging behaviors in the 4 wk leading up to the race. Screening for eating disorder behaviors should be considered in distance runners, particularly ultrarunners.
Introduction
Participation in ultramarathons, which includes running distances greater than the marathon distance of 42.2 km (26.2 mi), has increased significantly over the last decade. 1 Ultrarunners, or those who participate in ultramarathons, represent a small subset of the overall running population but can present with unique clinical considerations given the demands of the sport. 1 Because ultrarunners engage in longer distance training runs and races, it would be unsurprising to observe higher injury rates among ultrarunners than among shorter distance runners. Additionally, ultrarunners demonstrate high intrinsic motivation and drive for personal achievement, associated with the tendency to continue to engage in the sport even with the knowledge that it may harm their health, which could lead to increased injury risk. 2 However, past studies have reported that ultrarunners experience a similar annual incidence of overuse-related musculoskeletal injuries to that of habitual shorter distance runners. 3 In fact, one study demonstrated that ultrarunners had a lower rate of stress fractures than what has been reported in shorter distance runners, 4 which raises the question of what characteristics may be unique to ultrarunners that can affect injury rates.
Ultrarunners face particular challenges when it comes to sleep and nutrition.5,6 Specifically, ultrarunners reported increased daytime sleepiness compared with that of the general population, although their total mean sleep duration was similar. 5 Ultrarunners are also at a higher risk for the male or female athlete triad than the general population, which consists of the combination of low energy availability, low bone mineral density, and menstrual dysfunction or sex hormone insufficiency in females and males, respectively. 7 One study comparing female ultramarathoners and half marathoners reported significantly more ultramarathoners with 1, 2, or 3 components of the female athlete triad than half marathoners. 8 Because participation in ultrarunning continues to rise, it is important for healthcare professionals to understand the distinctive characteristics of ultrarunners in order to provide the most effective and comprehensive care.
Ultrarunning poses physical and mental challenges that may not only influence injury rates but also influence sleep and nutrition when compared with the challenges posed by shorter distance running. Therefore, the primary aim of the study was to compare select training and health characteristics between ultrarunners (participants in 50-km, 80.5-km [50-mi], and 100-km races) and shorter distance runners (participants in half marathon and 10-km races) who participated in a trail race series.
Methods
Participants and Study Design
We conducted a cross-sectional study of participants registered to complete a trail race series in the foothills of Colorado (estimated elevation, 1692 m [5554 ft]), including races at one of the following distances: 10 km, half marathon (20 km [13.1 mi]), 50 km, 80.5 km (50 mi), or 100 km. The race course was almost exclusively on single track dirt or packed gravel trails. Anyone between the ages of 18 and 70 y who was registered to complete one of the included races was eligible for the study. Colorado multiple institutional review board approval and approval from the race director was obtained prior to study commencement. Study data were collected and managed using Research Electronic Data Capture (REDCap). A questionnaire link through REDCap was sent to all registered participants via email through the race director’s communications; 2 email communications before the races and 1 email communication after the races including the questionnaire link were disseminated (see online Supplemental Material). Data collection ended after the races were completed. Informed consent was obtained electronically before the participants completed the questionnaire. Participants were divided into 2 groups on the basis of the distance of the race in which they participated: the ultramarathon/ultrarunner group (those completing the 50-km, 80.5-km [50-mi], or 100-km races) and the half marathon/10-km group.
Participant Reported Assessments
During the assessment, all participants completed a series of questionnaires, including health history, training history, and the Pittsburgh Quality Sleep Index (PSQI). The health history included questions regarding stress fracture diagnosis, menstrual function in female runners, and disordered eating behaviors, including self-reported episodes of binging and purging, with questions adapted from the Eating Disorder Examination Questionnaire. 9 The training history evaluated participants’ running volume, race participation, and resistance training habits.
The PSQI is a widely used assessment of self-reported sleep quality that asks about sleep habits within the month preceding completion of the questionnaire. 10 Within the PSQI, participants rated sleep quality and sleep disturbance on a set of 19 self-rated questions. The 19 self-rated items combined to form 7 component scores, including subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medications, and daytime dysfunction. The global PSQI score was determined by the sum of the 7 component scores, ranging from 0 to 21, with a higher score indicating poorer sleep quality. 10
Statistical Analyses
Data are presented as mean (SD) or median (interquartile range) for continuous variables and as the number including (corresponding percentage) for categorical variables. We compared continuous variables between ultramarathon and half marathon/10-km groups using independent sample t tests if normally distributed and Mann-Whitney U tests if nonnormally distributed. We compared categorical outcomes between groups using χ2 analyses or Fisher exact tests (if cell sizes were <5). Statistical analyses were 2-sided, and statistical significance was defined as P<0.05. All analyses were performed with Stata version 15 (StataCorp, College Station, TX).
Results
There were a total of 596 participants in the race series. We received 59 responses, resulting in a 10% overall response rate (5.7% response rate for the half marathon/10-km group and 15.3% response rate for the ultramarathon group). A total of 59 individuals completed the demographic, training, and health history components (Table 1), with 56 completing all aspects of the questionnaire, including diet history and the PSQI (Table 2). All available data were included in the analyses. Demographic and medical history characteristics, such as sex, age, body size, and injury history, did not significantly differ between the ultramarathon and half marathon/10-km groups (Table 1). There was no statistically significant difference in history of self-reported stress fracture between the ultramarathon and shorter distance groups (15% vs 9%; P=0.70; Table 1). Regarding training history, we found that a greater proportion of the ultrarunners indicated running a mean of >40 mi/wk over the 3 mo before the assessment, running more days/week, and running a race of marathon distance or greater in the past year compared with the half marathon/10K group (Table 1). However, the groups did not differ in the number of days/week they strength trained (Table 1).
Comparison of demographic, medical, and training history characteristics between half marathon/10-km and ultramarathon runners
BMI, body mass index.
Data are presented as means (SD) or number included (%).
Statistically significant.
Comparison of sleep, quality of life, and diet characteristics between half marathon/10-km and ultramarathon runners
Data are presented as means (SD) or number included (%).
Statistically significant.
We did not observe statistically significant between-group differences for sleep quality (PSQI score, small effect: Cohen’s d=0.47) or most disordered eating behavior questions. There were 2 ultrarunners who reported a history of a diagnosed eating disorder; these 2 participants were not the same 2 who reported self-induced vomiting behaviors (Table 2). We did observe a significantly greater proportion of the ultramarathon group reporting an episode of binging (defined as an episode of eating an unusually large amount of food, accompanied by the sense of having lost control) in the previous 4 weeks compared with the half marathon/10-km group (38% vs 3%; P=0.001; Table 2). We also observed that over one-third of both groups reported that they were currently trying to lose weight, and over half of both groups reported trying to change body weight/composition to improve performance; however, we did not observe significant between-group differences for these variables (Table 2).
Discussion
Our data demonstrated that ultrarunners run a greater training volume (increased mileage per week and days per week of running) than half marathon/10-km runners. Despite this, there were no significant differences in reported history of stress fracture. This observation aligns with prior research demonstrating similar injury rates between ultrarunners and shorter distance runners. 3 Although increased running distance has been found to be a risk factor for injury, suggested protective factors for ultrarunners include improved adaptability to running demands and more time running on softer surfaces (other than concrete and asphalt) compared with those for shorter distance runners. 3
One notable difference found between the groups was that more ultrarunners reported an episode of binge eating in the 4 weeks before the race compared with the runners in the half marathon/10-km group. Although 1 episode of binge eating accompanied by a sense of loss of control does not necessarily indicate an eating disorder, it may be suggestive of disordered eating behaviors compared with those who reported no such episodes. Although not significantly different between the groups in our study, there were also 2 ultrarunners who reported a history of an eating disorder diagnosis and 2 with an episode of self-induced vomiting in the previous 4 weeks compared with none in the half marathon/10-km group. This is in line with past studies that have reported that ultramarathoners are at risk for the male and female athlete triad, which can include disordered eating.7,11 One study demonstrated that 32% of female ultrarunners reported disordered eating behaviors, 11 and another observed that 44% of men and 62% of women ultrarunners were at risk of disordered eating, as determined by responses to eating disorder questionnaires. 7
Additionally, although we did not observe a statistically significant between-group difference, it is important to note that over half (59%) of the entire study sample reported that they were currently trying to change body weight or composition to improve performance, with over a third in both groups trying to lose weight. This aligns with a prior study that revealed that 60.5% of runners reported expected performance improvements with weight reduction. 11 Our data also indicate a difference in body weight and composition change behaviors between the groups. Although 65% of the ultramarathon group reported trying to change body weight or composition, only 31% reported trying to lose weight, suggesting that the ultrarunners may be attempting to alter body composition through means other than weight loss, such as changes in muscle mass or lean mass. In contrast, 53% of the half marathon/10-km group reported trying to change body weight or composition, with 43% trying to lose weight, suggestive of weight loss as the primary means for body weight/composition changes in the shorter distance group. It is known that male and female athletes engaged in weight-sensitive sports that emphasize leanness demonstrate higher prevalence of disordered eating behaviors. 12 Runners may believe that weight loss could enhance performance; however, restricting energy intake can lead to many physiological and performance-related detriments in the setting of relative energy deficiency in sport. 12 It is important for clinicians to recognize motives and modes for weight change and risk of disordered eating in runners to appropriately screen athletes and implement early interventions.
Our study had several limitations. First, the sample size was small and from a single site, and the response rate was low for the questionnaire, which may have underpowered the study. The length of the questionnaire may have been a deterrent, and we did not attempt alternative modes of participant recruitment besides email communications. We are limited in our ability to generalize findings to other geographic locations or populations of interest. The objective of our investigation was cross-sectional, and therefore, we cannot infer any causal relationships.
Conclusions
Ultrarunners demonstrated a significantly greater training volume than that demonstrated by half marathon/10-km runners. Despite this, there was no significant difference in the prevalence of stress fractures or sleep quality between the groups. There was a high reported prevalence of runners attempting to change body weight for performance enhancement in both groups, with significantly more ultrarunners reporting binge eating behaviors in the 4 wk leading up to the race. Our study would have been strengthened by a larger sample size; alternative modes of questionnaire distribution, such as through flyers and/or a quick response (QR) code at race packet pick-up, could have been employed to enhance participant recruitment. Better understanding of the training and health characteristics of ultrarunners will allow clinicians to provide more comprehensive care to the population and contribute to the development of injury prevention and athlete education.
Footnotes
Funding
Disclosures: DRH has received research support from the Eunice Kennedy Shriver National Institute of Child Health & Human Development (R03HD094560 and R01HD108133), the National Institute of Neurological Disorders and Stroke (R01NS100952 and R43NS108823), the National Institute of Arthritis and Musculoskeletal and Skin Diseases (1R13AR080451), MINDSOURCE Brain Injury Network, the Tai Foundation, and the Colorado Clinical and Translational Sciences Institute (UL1 TR002535-05), and he serves on the Scientific/Medical Advisory Board of Synaptek, LLC. All other participating authors have no competing interests to declare.
Acknowledgements
Author Contributions: study concept and design (AMA, CNS, DRH); data acquisition (AMA, CNS DRH); data analysis (AMA, KDV, DRH); drafting and critical revision of the manuscript (AMA, KDV, CNS, DRH); approval of final manuscript (AMA, KDV, CNS, DRH).
Financial/Material Support: None.
Supplemental Material(s)
Supplementary material associated with this article can be found in the online version at
References
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