The foot in multistage ultra-marathon runners: experience in a cohort study of 22 participants of the Trans Europe Footrace Project with mobile MRI

Mobile imaging trailers: A scoping review of CT and MRI modalities

INTRODUCTION

Mobile Imaging Trailers enable moving diagnostic imaging equipment between locations requiring very little setup and configuration, example given CT-scanners and MRI-scanners. However, despite the apparent benefits of utilising these imaging capabilities, very little research on the subject exists. This study aims at gaining an overview of the current state of the literature, using the scoping review methodology.

METHODS

The systematic literature search was conducted in three databases: Scopus, Embase and PubMed. Included sources were extracted based on the objectives of the scoping review, and inspired by the by PRISMA-ScR.

RESULTS

29 papers were included.

CONCLUSION

The results of the review showed that three general categories of research on this subject exist - trailers used in research, trailers as the object of research and trailers as an element or tool of the research. Of these, the most prevalent one used is the latter - trailers used as an element or tool of the research. This; however, is an issue for the use of trailers in a clinical setting, as very little research has been conducted on how they might be used and how they compare to fixed installations. As seen during the recent COVID-19 pandemic, the potentials for the use of MITs are immense; however, with the current lack of knowledge and understanding, the full potential has not been realised, suggesting further research should be focused in this area.

IMPLICATIONS FOR PRACTICE

This study has shown that the limited research in the area does point towards a few benefits of MITs; however, there is a clear lack of sufficient research on the field to say this with confidence.

Foot and Ankle Bone Marrow Edema Assessment in Long Distance Runners

BACKGROUND

The clinical significance of foot and ankle bone marrow edema (BME) is poorly understood.

METHODS

Magnetic resonance imaging (MRI) and the visual analog scale (VAS) pain scores were collected for 17 runners who participated in the Twin Cities Marathon, immediately postmarathon and at a 6-week follow-up. Bone marrow edema lesions were classified using lesion frequency, anatomical location, and grading scale change to calculate a BME score for each affected bone. Spearman rank correlation coefficient test was used to identify a possible correlation between VAS and postmarathon BME. A paired Student t test was used to detect differences between total mileage ran 6 weeks postmarathon in participants with or without BME.

RESULTS

After completing the marathon, 8 BME lesions were identified in 5 participants (29.4%; 5/17), 3 were men, and 2 were women, with a mean age of 33.8 years (range: 24-52), and BMI of 22.9 ± 4. All lesions were resolved on 6-week follow-up imaging. VAS pain scores did not correlate with postmarathon BME. A significant difference in total miles logged over 6 weeks postmarathon could not be found among participants with and without BME.

CONCLUSION

Foot and ankle BME changes identified by MRI were not correlated to clinical symptoms and may resolve with self-directed activity in less time than other areas of the lower extremity.

LEVEL OF EVIDENCE

Level II, Prospective Cohort Study.

Contemporary Review: The Foot and Ankle in Long-Distance Running

Distance runners represent a unique patient population. The cyclic activity associated with distance running leads to a high incidence of injury. Gait patterns, the extrinsic and intrinsic muscles of the foot and ankle, foot strike pattern, shoe wear considerations, alignment, and orthotics are also all important considerations that must be considered by the treating provider. The purpose of this work is to review relevant functional anatomy, recent studies on gait patterns in running, orthotics, and theory on how the body moves through space during running in order to better equip the clinician to treat long distance runners.

MRI features of and factors related to ankle injuries in asymptomatic amateur marathon runners

OBJECTIVE

To analyze the MRI manifestations of and factors related to ankle injuries in asymptomatic amateur marathon runners.

MATERIALS AND METHODS

A total of 113 amateur marathon runners without any ankle joint symptoms were recruited. Each participant was asked to complete a questionnaire at the beginning of the study and underwent MRI of the ankle. The MRI manifestations of ankle injuries were summarized, and binary logistic regression analysis was applied to analyze the factors related to ankle injuries.

RESULTS

The main MRI features were bone marrow edema-like signal intensity, peritendinous effusion, and partial lateral collateral ligament injury. Others included Achilles tendinopathy, cyst-like lesions, osteochondral lesions, and subcutaneous soft tissue edema. The risk factor for bone marrow edema-like signal intensity in amateur marathon runners was a rearfoot strike pattern (p = 0.028, OR = 1.172); the risk factors for peritendinous effusion were a higher weekly running distance (p = 0.013, OR = 1.685) and increased running years (p = 0.039, OR = 1.113), whereas a rearfoot strike pattern (p = 0.005, OR = 0.831) was a protective factor for peritendinous effusion; the risk factor for Achilles tendinopathy was increased age (p = 0.008, OR = 1.412); the risk factors for anterior talofibular ligament injury were a rearfoot strike pattern (p = 0.017, OR = 1.346) and higher weekly running distance (p = 0.022, OR = 1.171); and the factors for calcaneofibular ligament injury were a higher weekly running distance (p = 0.029, OR = 1.570) and rearfoot strike pattern (p = 0.035, OR = 1.463).

CONCLUSION

The main MRI features of asymptomatic amateur marathon runners are bone marrow edema-like signal intensity, peritendinous effusion, and partial lateral collateral ligament injury. In addition, increased age, increased running years, higher weekly running distance, and different foot strike patterns are risk factors for ankle injuries.

Long distance running - Can bioprofiling predict success in endurance athletes?

The TransEuropeFootRace (TEFR) was one of the most extreme multistage competitions worldwide. The ultramarathon took the runners over a distance of 4487 km, from Bari, Italy, to the North Cape, Norway, in 64 days. The participating ultra-long-distance runners had to complete almost two marathons per day (~70 km). The race was accompanied by a research team analysing adaptations of different organ systems of the human body that were exposed to a chronic lack of regeneration time. Here, we analyzed runner's urine using mass spectrometric profiling of thousands of low-molecular weight compounds. The results indicated that pre-race molecular factors can predict finishers and separate them from nonfinishers already before the race. These observations were related to the training volume as finishers ran about twice as many kilometers per week before TEFR than nonfinishers, thus apparently achieving a higher performance level and resistance against overuse. While this hypothesis needs to be validated in future long-distance races, the bioprofiling experiments suggest that the competition readiness of the runners is measurable and might be adjustable.

A mobile MRI field study of the biochemical cartilage reaction of the knee joint during a 4,486 km transcontinental multistage ultra-marathon using T2* mapping

Nearly nothing is known about the consequences of ultra-long-distance running on knee cartilage. In this mobile MRI field study, we analysed the biochemical effects of a 4,486 km transcontinental multistage ultra-marathon on femorotibial joint (FTJ) cartilage. Serial MRI data were acquired from 22 subjects (20 male, 18 finisher) using a 1.5 T MR scanner mounted on a 38-ton trailer, travelling with the participants of the TransEurope FootRace (TEFR) day by day over 64 stages. The statistical analyses focused on intrachondral T2* behaviour during the course of the TEFR as the main outcome variable of interest. T2* mapping (sagittal FLASH T2* weighted gradient echo) is a validated and highly accurate method for quantitative compositional cartilage analysis of specific weightbearing areas of the FTJ. T2* mapping is sensitive to changes in the equilibrium of free intrachondral water, which depends on the content and orientation of collagen and the proteoglycan content in the extracellular cartilage matrix. Within the first 1,100 km, a significant running load-induced T2* increase occurred in all joint regions: 44.0% femoral-lateral, 42.9% tibial-lateral, 34.9% femoral-medial, and 25.1% tibial-medial. Osteochondral lesions showed no relevant changes or new occurrence during the TEFR. The reasons for stopping the race were not associated with knee problems. As no further T2* elevation was found in the second half of the TEFR but a decreasing T2* trend (recovery) was observed after the 3,500 km run, we assume that no further softening of the cartilage occurs with ongoing running burden over ultra-long distances extending 4,500 km. Instead, we assume the ability of the FTJ cartilage matrix to reorganize and adapt to the load.

ACR Appropriateness Criteria® Acute Trauma to the Foot

Acute injuries to the foot are frequently encountered in the emergency room and in general practice settings. This publication defines best practices for imaging evaluations for several variants of patients presenting with acute foot trauma. The variants include scenarios when the Ottawa rules can be evaluated, when there are exclusionary criteria, and when suspected pathology is in anatomic areas not addressed by the Ottawa rules. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

How do tendons adapt? Going beyond tissue responses to understand positive adaptation and pathology development: A narrative review

Understanding how tendons adapt to load is crucial to understanding how training can improve performance, minimise the risk of injury and aid rehabilitation. Adaptation is the positive response of an organism or tissue to benefit its function. In tendons, numerous tissue responses to load have been identified in vivo. Changes in tendon dimensions, structure on imaging, mechanical properties, and blood flow have been reported in response to mechanical stimuli. However, research has focused on tissue level changes with little understanding of how changes at the tissue level affect the person, their athletic performance or injury risk. Tendons can have a paradoxical response to load, load can induce positive adaptation, however it is also a major factor in the development of tendon pathology and pain. Tendon pathology is a risk factor for developing symptoms, yet the high rate of asymptomatic pathology suggests that the pathological tendon must adapt to be able to tolerate load. Similarly, there is mounting evidence to suggest that tendon remodelling or repair is not necessary for a positive clinical outcome following rehabilitation, suggesting that the tendon must adapt via other mechanisms. This narrative review synthesises evidence of how normal and pathological tendons adapts to load, and how this relates to adaptation of load capacity and function of the individual.

Pacing and Changes in Body Composition in 48 h Ultra-Endurance Running-A Case Study

Pacing has been investigated in elite and master runners competing in marathon and ultra-marathon races up to 100 km and 100 miles, but not in longer ultra-marathons. In this case study, a 54-year-old master ultra-marathoner—intending to achieve as many kilometers as possible in a 48 h run—was examined. The changes in running speed during the race and selected anthropometric characteristics using bioelectrical impedance analysis (i.e., body mass and body water), during and after the race, were analyzed. The runner achieved a total distance of 230 km and running speed decreased non-linearly during the race. Body mass decreased, while percent body water increased, non-linearly, across the race. There was no statistically significant relationship between the decrease in body mass and the increase in percent body water. Considering the popularity of ultra-endurance running races, the findings of the present study offered valuable insight in the pacing and changes of body mass and body water during a 48 h run, and this information can be used by ultra-endurance runners and practitioners working with them.

Changes in Pain and Nutritional Intake Modulate Ultra-Running Performance: A Case Report

Ultra-endurance running provides numerous physiological, psychological, and nutritional challenges to the athlete and supporting practitioners. We describe the changes in physiological status, psychological condition, and nutritional intake over the course of two 100-mile running races, with differing outcomes: non-completion and completion. Athlete perception of pain, freshness, and motivation differed between events, independent of rating of perceived exertion. Our data suggest that the integration of multiple sensations (freshness, motivation, hunger, pain, and thirst) produce performance. Increases in carbohydrate feeding (+5 g·h⁻¹) and protein intake (+0.3 g·kg⁻¹) also likely contributed to successful completion of a 100-mile race, by reducing the fractional utilization of maximal oxygen uptake and satiating hunger, respectively. Nutritional data support the notion that the gut is a trainable, and critical organ with respect to ultra-endurance performance. Finally, we propose future research to investigate the rate at which peak feeding occurs throughout ultra-endurance events, as this may further serve to personalize sports nutrition strategies.

Physiology and Pathophysiology in Ultra-Marathon Running

In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of ultra-marathon running. The number of ultra-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical ultra-marathoner is male, married, well-educated, and ~45 years old. Female ultra-marathoners account for ~20% of the total number of finishers. Ultra-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in ultra-marathon races and personal best marathon time) is the most important predictor variable for a successful ultra-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat) and training (e.g., high volume and running speed during training) characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10–20% depending upon the length of the ultra-marathon. The fastest ultra-marathon race times are generally achieved at the age of 35–45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An ultra-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An ultra-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold) or the country where the race is held, can lead to exercise-associated hyponatremia. An ultra-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In longer ultra-marathons, ~50–60% of the participants experience musculoskeletal problems. The most common injuries in ultra-marathoners involve the lower limb, such as the ankle and the knee. An ultra-marathon can lead to an increase in creatine-kinase to values of 100,000–200,000 U/l depending upon the fitness level of the athlete and the length of the race. Furthermore, an ultra-marathon can lead to changes in the heart as shown by changes in cardiac biomarkers, electro- and echocardiography. Ultra-marathoners often suffer from digestive problems and gastrointestinal bleeding after an ultra-marathon is not uncommon. Liver enzymes can also considerably increase during an ultra-marathon. An ultra-marathon often leads to a temporary reduction in renal function. Ultra-marathoners often suffer from upper respiratory infections after an ultra-marathon. Considering the increased number of participants in ultra-marathons, the findings of the present review would have practical applications for a large number of sports scientists and sports medicine practitioners working in this field.

[Not Available]

Zusammenfassung. In den vergangenen Jahrzehnten hat sich die Zahl der Ultraläufer vervielfacht, und viele Studien haben den Einfluss auf den Bewegungsapparat untersucht. Wir stellen die Erkenntnisse zu Schäden zusammen, die ein Ultramarathon an Gelenken und Muskeln verursachen kann. Die häufigsten Verletzungen bzw. Überlastungsschäden betreffen die untere Extremität, wobei Sprunggelenk und Knie am häufigsten betroffen sind. Bei sehr langen Läufen kommt es zu einer Anpassung mit Verdickung von Sehnen und Knorpel. Ein Ultramarathon kann zu einem ausgeprägten Muskelschaden führen, mit einem Anstieg von myozellulären Metaboliten wie Myoglobin, Laktat-Dehydrogenase und Creatinkinase.

Revisiting the continuum model of tendon pathology: what is its merit in clinical practice and research?

The pathogenesis of tendinopathy and the primary biological change in the tendon that precipitates pathology have generated several pathoaetiological models in the literature. The continuum model of tendon pathology, proposed in 2009, synthesised clinical and laboratory-based research to guide treatment choices for the clinical presentations of tendinopathy. While the continuum has been cited extensively in the literature, its clinical utility has yet to be fully elucidated. The continuum model proposed a model for staging tendinopathy based on the changes and distribution of disorganisation within the tendon. However, classifying tendinopathy based on structure in what is primarily a pain condition has been challenged. The interplay between structure, pain and function is not yet fully understood, which has partly contributed to the complex clinical picture of tendinopathy. Here we revisit and assess the merit of the continuum model in the context of new evidence. We (1) summarise new evidence in tendinopathy research in the context of the continuum, (2) discuss tendon pain and the relevance of a model based on structure and (3) describe relevant clinical elements (pain, function and structure) to begin to build a better understanding of the condition. Our goal is that the continuum model may help guide targeted treatments and improved patient outcomes.

Feet swelling in a multistage ultraendurance triathlete: a case study

Recent studies investigating ultraendurance athletes showed an association between excessive fluid intake and swelling of the lower limbs such as the feet. To date, this association has been investigated in single-stage ultraendurance races, but not in multistage ultraendurance races. In this case study, we investigated a potential association between fluid intake and feet swelling in a multistage ultraendurance race such as a Deca Iron ultratriathlon with ten Ironman triathlons within 10 consecutive days. A 49-year-old well-experienced ultratriathlete competed in autumn 2013 in the Deca Iron ultratriathlon held in Lonata del Garda, Italy, and finished the race as winner within 129:33 hours:minutes. Changes in body mass (including body fat and lean body mass), foot volume, total body water, and laboratory measurements were assessed. Food and fluid intake during rest and competing were recorded, and energy and fluid turnovers were estimated. During the ten stages, the volume of the feet increased, percentage body fat decreased, creatinine and urea levels increased, hematocrit and hemoglobin values decreased, and plasma [Na⁺] remained unchanged. The increase in foot volume was significantly and positively related to fluid intake during the stages. The poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. This case report shows that the volume of the foot increased during the ten stages, and the increase in volume was significantly and positively related to fluid intake during the stages. Furthermore, the poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. The continuous feet swelling during the race was most probably due to a combination of a high fluid intake and a progressive decline in renal function (ie, continuous increase in creatinine and urea), leading to body fluid retention (ie, increase in total body water).

The increase in hydric volume is associated to contractile impairment in the calf after the world's most extreme mountain ultra-marathon

Background

Studies have recently focused on the effect of running a mountain ultra-marathon (MUM) and their results show muscular inflammation, damage and force loss. However, the link between peripheral oedema and muscle force loss is not really established. We tested the hypothesis that, after a MUM, lower leg muscles’ swelling could be associated with muscle force loss. The knee extensor (KE) and the plantar flexor (PF) muscles’ contractile function was measured by supramaximal electrical stimulations, potentiated low- and high-frequency doublets (PS10 and PS100) of the KE and the PF were measured by transcutaneous electrical nerve stimulation and bioimpedance was used to assess body composition in the runners (n = 11) before (Pre) and after (Post) the MUM and compared with the controls (n = 8).

Results

The maximal voluntary contraction of the KE and the PF significantly decreased by 20 % Post-MUM in the runners. Hydration of the non-fat mass (NF-Hyd) and extracellular water volume (Ve) were increased by 12 % Post-MUM (p < 0.001) in the runners. Calf circumference (+2 %, p < 0.05) was also increased. Significant relationships were found for percentage increases in Ve and NF-Hyd with percentage decrease in PS10 of the PF (r = −0.68 and r = −0.70, p < 0.05) and with percentage increase of calf circumference (r = 0.72 and r = 0.73, p < 0.05) in the runners.

Conclusions

The present study suggests that increases in circumference and in hydric volume are associated to contractile impairment in the calf in ultra-marathon runners.

A comparison of performance of Deca Iron and Triple Deca Iron ultra-triathletes

This study intended to compare the performance of ultra-triathletes competing in a Deca Iron ultra-triathlon (i.e. 10 times 3.8 km swimming, 180 km cycling, and 42.2 km running) with the performance of athletes competing in a Triple Deca Iron ultra-triathlon (i.e. 30 times 3.8 km swimming, 180 km cycling, and 42.2 km running). Split and overall race times of six male finishers in a Deca Iron ultra-triathlon and eight male finishers in a Triple Deca Iron ultra-triathlon were analysed using multiple t-tests, linear and non-linear regression analyses, and analysis of variance. Among the 19 starters (i.e. 17 men and two women) in the Deca Iron ultra-triathlon, six men (i.e. 35.3% of all starters) finished the race. The mean swimming, cycling, running and overall race times of the six finishers across the ten days were 1:19 ± 0:09 h:min, 6:36 ± 0:19 h:min, 6:03 ± 0:47 h:min and 14:44 ± 1:17 h:min, respectively. The times of the split disciplines and overall race time increased linearly across the ten days. Total transition times did not change significantly across the days and were equals to 48 ± 8 min. Among the 22 starters (i.e. 20 men and two women) in the Triple Deca Iron ultra-triathlon, eight men (i.e. 36.4% of all starters) finished. The mean swimming, cycling, running and overall race times of the eight finishers across the 30 days were 1:11 ± 0:07 h:min, 6:19 ± 0:32 h:min, 5:34 ± 1:15 h:min and 13:44 ± 1:50 h:min, respectively. Split and overall race times showed no change across the 30 days. Total transition times showed no change across the days and were equal to 41 ± 11 min. To summarize, the daily performance decreased across the ten days for the Deca Iron ultra-triathletes (i.e. positive pacing) while it remained unchanged across the 30 days for the Triple Deca Iron ultra-triathletes (i.e. even pacing).

Regionally accentuated reversible brain grey matter reduction in ultra marathon runners detected by voxel-based morphometry

Background

During the 4,487 km ultra marathon TransEurope-FootRace 2009 (TEFR09), runners showed catabolism with considerable reduction of body weight as well as reversible brain volume reduction. We hypothesized that ultra marathon athletes might have developed changes to grey matter (GM) brain morphology due to the burden of extreme physical training. Using voxel-based morphometry (VBM) we undertook a cross sectional study and two longitudinal studies.

Methods

Prior to the start of the race 13 runners volunteered to participate in this study of planned brain scans before, twice during, and 8 months after the race. A group of matched controls was recruited for comparison. Twelve runners were able to participate in the scan before the start of the race and were taken into account for comparison with control persons. Because of drop-outs during the race, VBM could be performed in 10 runners covering the first 3 time points, and in 7 runners who also had the follow-up scan after 8 months. Volumetric 3D datasets were acquired using an MPRAGE sequence. A level of p < 0.05, family-wise corrected for multiple comparisons was the a priori set statistical threshold to infer significant effects from VBM.

Results

Baseline comparison of TEFR09 participants and controls revealed no significant differences regarding GM brain volume. During the race however, VBM revealed GM volume decreases in regionally distributed brain regions. These included the bilateral posterior temporal and occipitoparietal cortices as well as the anterior cingulate and caudate nucleus. After eight months, GM normalized.

Conclusion

Contrary to our hypothesis, we did not observe significant differences between TEFR09 athletes and controls at baseline. If this missing difference is not due to small sample size, extreme physical training obviously does not chronically alter GM.

However, during the race GM volume decreased in brain regions normally associated with visuospatial and language tasks. The reduction of the energy intensive default mode network as a means to conserve energy during catabolism is discussed. The changes were reversible after 8 months.

Despite substantial changes to brain composition during the catabolic stress of an ultra marathon, the observed differences seem to be reversible and adaptive.

Increase in finishers and improvement of performance of masters runners in the Marathon des Sables

Aim

The aim of the study was to examine finisher and performance trends of ultrarunners in the Marathon des Sables, the world’s largest multistage ultramarathon.

Methods

The age and running speed was analyzed for 6945 finishes of 909 women and 6036 men between 2003 and 2012 at the Marathon des Sables covering about 240 km in the Moroccan desert.

Results

The number of finishes increased significantly for both women and men from 2003–2012. The annual number of finishes increased in age groups: 30–34 years (r² = 0.50; P = 0.021), 45–49 years (r² = 0.81; P = 0.0004), and 50–54 years (r² = 0.46; P = 0.029) for women and in all age groups older than 35 years for men (35–39 years: r² = 0.64, P = 0.0054; 40–44 years: r² = 0.67, P = 0.0036; 45–49 years: r² = 0.77, P = 0.0007; 50–54 years: r² = 0.72, P = 0.0018; 55–59 years: r² = 0.42, P = 0.041; and 60–64 years: r² = 0.67, P = 0.0038). The fastest running speed was achieved by runners in the age group of 35–39 years for both sexes. The mean age of overall finishers was 41.0 ± 9.1 years for women and 41.3 ± 9.5 years for men. For men, running speed improved for athletes in the age group of 35–39 years (r² = 0.44; P = 0.036) and of 40–44 years (r² = 0.51; P = 0.019), while it decreased for athletes in the age group of 30–34 years (r² = 0.66, P = 0.0039). For women, running speed remained stable during the study period for athletes in all age groups.

Conclusion

These data suggest that the number of finishers of masters runners older than 40 years increased for both sexes at the Marathon des Sables, as has been previously observed for single-stage ultramarathons. In contrast to women, men aged 35 to 44 years improved running speed during the study period. Future studies are needed to investigate the reasons for the growing numbers of masters athletes in endurance sports and their improvement in performance.

The effects of prolonged running on foot posture: a repeated measures study of half marathon runners using the foot posture index and navicular height

Background

Different foot postures are associated with alterations in foot function, kinetics and the subsequent occurrence of injury. Little is known about changes in foot posture following prolonged weightbearing exercise. This study aimed to identify changes in foot posture after running a half marathon.

Methods

Foot posture was measured using the Foot Posture Index (FPI-6) and navicular height in thirty volunteer participants before and after running a half marathon. FPI-6 scores were converted to Rasch logit values and means compared for these and navicular height using an ANOVA.

Results

There was a 5 mm drop in navicular height in both feet when measured after the half marathon (P < 0.05). The FPI-6 showed a side x time interaction with an increase in score indicating a more ‘pronated’ position in the left foot of + 2 [Rasch value + 1.7] but no change in the right foot (+ 0.4 [+ 0.76]) following the half marathon.

Conclusion

The apparent differences between the FPI-6 and navicular height on the right foot may be because the FPI-6 takes soft tissue contour changes into consideration whilst the navicular height focuses on skeletal changes. The changes in foot posture towards a more pronated position may have implications for foot function, and therefore risk of injury; shoe fit and comfort and also the effect of therapeutic orthoses worn during prolonged running.

Characteristics, changes and influence of body composition during a 4486 km transcontinental ultramarathon: results from the TransEurope FootRace mobile whole body MRI-project

BACKGROUND

Almost nothing is known about the medical aspects of runners doing a transcontinental ultramarathon over several weeks. The results of differentiated measurements of changes in body composition during the Transeurope Footrace 2009 using a mobile whole body magnetic resonance (MR) imager are presented and the proposed influence of visceral and somatic adipose and lean tissue distribution on performance tested.

METHODS

22 participants were randomly selected for the repeated MR measurements (intervals: 800 km) with a 1.5 Tesla MR scanner mounted on a mobile unit during the 64-stage 4,486 km ultramarathon. A standardized and validated MRI protocol was used: T1 weighted turbo spin echo sequence, echo time 12 ms, repetition time 490 ms, slice thickness 10 mm, slice distance 10 mm (breath holding examinations). For topographic tissue segmentation and mapping a modified fuzzy c-means algorithm was used. A semi-automatic post-processing of whole body MRI data sets allows reliable analysis of the following body tissue compartments: Total body volume (TV), total somatic (TSV) and total visceral volume (TVV), total adipose (TAT) and total lean tissue (TLT), somatic (SLT) and visceral lean tissue (VLT), somatic (SAT) and visceral adipose tissue (VAT) and somatic adipose soft tissue (SAST). Specific volume changes were tested on significance. Tests on difference and relationship regarding prerace and race performance and non-finishing were done using statistical software SPSS.

RESULTS

Total, somatic and visceral volumes showed a significant decrease throughout the race. Adipose tissue showed a significant decrease compared to the start at all measurement times for TAT, SAST and VAT. Lean adipose tissues decreased until the end of the race, but not significantly. The mean relative volume changes of the different tissue compartments at the last measurement compared to the start were: TV -9.5% (SE 1.5%), TSV -9.4% (SE 1.5%), TVV -10.0% (SE 1.4%), TAT -41.3% (SE 2.3%), SAST -48.7% (SE 2.8%), VAT -64.5% (SE 4.6%), intraabdominal adipose tissue (IAAT) -67.3% (SE 4.3%), mediastinal adopose tissue (MAT) -41.5% (SE 7.1%), TLT -1.2% (SE 1.0%), SLT -1.4% (SE 1.1%). Before the start and during the early phase of the Transeurope Footrace 2009, the non-finisher group had a significantly higher percentage volume of TVV, TAT, SAST and VAT compared to the finisher group. VAT correlates significantly with prerace training volume and intensity one year before the race and with 50 km- and 24 hour-race records. Neither prerace body composition nor specific tissue compartment volume changes showed a significant relationship to performance in the last two thirds of the Transeurope Footrace 2009.

CONCLUSIONS

With this mobile MRI field study the complex changes in body composition during a multistage ultramarathon could be demonstrated in detail in a new and differentiated way. Participants lost more than half of their adipose tissue. Even lean tissue volume (mainly skeletal muscle tissue) decreased due to the unpreventable chronic negative energy balance during the race. VAT has the fastest and highest decrease compared to SAST and lean tissue compartments during the race. It seems to be the most sensitive morphometric parameter regarding the risk of non-finishing a transcontinental footrace and shows a direct relationship to prerace-performance. However, body volume or body mass and, therefore, fat volume has no correlation with total race performances of ultra-athletes finishing a 4,500 km multistage race.

Ultramarathon runners: nature or nurture?

Ultramarathon running is increasingly popular. An ultramarathon is defined as a running event involving distances longer than the length of a traditional marathon of 42.195 km. In ultramarathon races, ~80% of the finishers are men. Ultramarathoners are typically ~45 y old and achieve their fastest running times between 30 and 49 y for men, and between 30 and 54 y for women. Most probably, ultrarunners start with a marathon before competing in an ultramarathon. In ultramarathoners, the number of previously completed marathons is significantly higher than the number of completed marathons in marathoners. However, recreational marathoners have a faster personal-best marathon time than ultramarathoners. Successful ultramarathoners have 7.6 ± 6.3 y of experience in ultrarunning. Ultramarathoners complete more running kilometers in training than marathoners do, but they run more slowly during training than marathoners. To summarize, ultramarathoners are master runners, have a broad experience in running, and prepare differently for an ultramarathon than marathoners do. However, it is not known what motivates male ultramarathoners and where ultramarathoners mainly originate. Future studies need to investigate the motivation of male ultramarathoners, where the best ultramarathoners originate, and whether they prepare by competing in marathons before entering ultramarathons.