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1.  The Transeurope Footrace Project: longitudinal data acquisition in a cluster randomized mobile MRI observational cohort study on 44 endurance runners at a 64-stage 4,486km transcontinental ultramarathon 
BMC Medicine  2012;10:78.
Background
The TransEurope FootRace 2009 (TEFR09) was one of the longest transcontinental ultramarathons with an extreme endurance physical load of running nearly 4,500 km in 64 days. The aim of this study was to assess the wide spectrum of adaptive responses in humans regarding the different tissues, organs and functional systems being exposed to such chronic physical endurance load with limited time for regeneration and resulting negative energy balance. A detailed description of the TEFR project and its implemented measuring methods in relation to the hypotheses are presented.
Methods
The most important research tool was a 1.5 Tesla magnetic resonance imaging (MRI) scanner mounted on a mobile unit following the ultra runners from stage to stage each day. Forty-four study volunteers (67% of the participants) were cluster randomized into two groups for MRI measurements (22 subjects each) according to the project protocol with its different research modules: musculoskeletal system, brain and pain perception, cardiovascular system, body composition, and oxidative stress and inflammation. Complementary to the diverse daily mobile MR-measurements on different topics (muscle and joint MRI, T2*-mapping of cartilage, MR-spectroscopy of muscles, functional MRI of the brain, cardiac and vascular cine MRI, whole body MRI) other methods were also used: ice-water pain test, psychometric questionnaires, bioelectrical impedance analysis (BIA), skinfold thickness and limb circumference measurements, daily urine samples, periodic blood samples and electrocardiograms (ECG).
Results
Thirty volunteers (68%) reached the finish line at North Cape. The mean total race speed was 8.35 km/hour. Finishers invested 552 hours in total. The completion rate for planned MRI investigations was more than 95%: 741 MR-examinations with 2,637 MRI sequences (more than 200,000 picture data), 5,720 urine samples, 244 blood samples, 205 ECG, 1,018 BIA, 539 anthropological measurements and 150 psychological questionnaires.
Conclusions
This study demonstrates the feasibility of conducting a trial based centrally on mobile MR-measurements which were performed during ten weeks while crossing an entire continent. This article is the reference for contemporary result reports on the different scientific topics of the TEFR project, which may reveal additional new knowledge on the physiological and pathological processes of the functional systems on the organ, cellular and sub-cellular level at the limits of stress and strain of the human body.
Please see related articles: http://www.biomedcentral.com/1741-7015/10/76 and http://www.biomedcentral.com/1741-7015/10/77
doi:10.1186/1741-7015-10-78
PMCID: PMC3409063  PMID: 22812450
2.  Substantial and reversible brain gray matter reduction but no acute brain lesions in ultramarathon runners: experience from the TransEurope-FootRace Project 
BMC Medicine  2012;10:170.
Background
During the extremely challenging 4,487 km ultramarathon TransEurope-FootRace 2009, runners showed considerable reduction of body weight. The effects of this endurance run on brain volume changes but also possible formation of brain edema or new lesions were explored by repeated magnetic resonance imaging (MRI) studies.
Methods
A total of 15 runners signed an informed consent to participate in this study of planned brain scans before, twice during, and about 8 months after the race. Because of dropouts, global gray matter volume analysis could only be performed in ten runners covering three timepoints, and in seven runners who also had a follow-up scan. Scanning was performed on three identical 1.5 T Siemens MAGNETOM Avanto scanners, two of them located at our university. The third MRI scanner with identical sequence parameters was a mobile MRI unit escorting the runners. Volumetric 3D datasets were acquired using a magnetization prepared rapid acquisition gradient echo (MPRAGE) sequence. Additionally, diffusion-weighted (DWI) and fluid attenuated inversion recovery (FLAIR) imaging was performed.
Results
Average global gray matter volume as well as body weight significantly decreased by 6% during the race. After 8 months, gray matter volume returned to baseline as well as body weight. No new brain lesions were detected by DWI or FLAIR imaging.
Conclusions
Physiological brain volume reduction during aging is less than 0.2% per year. Therefore a volume reduction of about 6% during the 2 months of extreme running appears to be substantial. The reconstitution in global volume measures after 8 months shows the process to be reversible. As possible mechanisms we discuss loss of protein, hypercortisolism and hyponatremia to account for both substantiality and reversibility of gray matter volume reductions. Reversible brain volume reduction during an ultramarathon suggests that extreme running might serve as a model to investigate possible mechanisms of transient brain volume changes. However, despite massive metabolic load, we found no new lesions in trained athletes participating in a multistage ultramarathon.
See related commentary http://www.biomedcentral.com/1741-7015/10/171
doi:10.1186/1741-7015-10-170
PMCID: PMC3566943  PMID: 23259507
body weight; brain volume; catabolism; DWI; lesion; MRI; ultramarathon
3.  Evidence from neuroimaging to explore brain plasticity in humans during an ultra-endurance burden 
BMC Medicine  2012;10:171.
Physical activity, likely through induction of neuroplasticity, is a promising intervention to promote brain health. In athletes it is clear that training can and does, by physiological adaptations, extend the frontiers of performance capacity. The limits of our endurance capacity lie deeply in the human brain, determined by various personal factors yet to be explored. The human brain, with its vast neural connections and its potential for seemingly endless behaviors, constitutes one of the final frontiers of medicine. In a recent study published in BMC Medicine, the TransEurope FootRace Project followed 10 ultra-endurance runners over around 4,500 km across Europe and recorded a large data collection of brain imaging scans. This study indicates that the cerebral atrophy amounting to a reduction of approximately 6% throughout the two months of the race is reversed upon follow-up. While this study will contribute to advances in the limits of human performance on the neurophysiological processes in sports scientists, it will also bring important understanding to clinicians about cerebral atrophy in people who are vulnerable to physical and psychological stress long term.
See related research article http://www.biomedcentral.com/1741-7015/10/170
doi:10.1186/1741-7015-10-171
PMCID: PMC3566949  PMID: 23259535
cerebral atrophy; exercise behavior; fatigue; overload; plasticity; running
4.  Metabolic Factors Limiting Performance in Marathon Runners 
PLoS Computational Biology  2010;6(10):e1000960.
Each year in the past three decades has seen hundreds of thousands of runners register to run a major marathon. Of those who attempt to race over the marathon distance of 26 miles and 385 yards (42.195 kilometers), more than two-fifths experience severe and performance-limiting depletion of physiologic carbohydrate reserves (a phenomenon known as ‘hitting the wall’), and thousands drop out before reaching the finish lines (approximately 1–2% of those who start). Analyses of endurance physiology have often either used coarse approximations to suggest that human glycogen reserves are insufficient to fuel a marathon (making ‘hitting the wall’ seem inevitable), or implied that maximal glycogen loading is required in order to complete a marathon without ‘hitting the wall.’ The present computational study demonstrates that the energetic constraints on endurance runners are more subtle, and depend on several physiologic variables including the muscle mass distribution, liver and muscle glycogen densities, and running speed (exercise intensity as a fraction of aerobic capacity) of individual runners, in personalized but nevertheless quantifiable and predictable ways. The analytic approach presented here is used to estimate the distance at which runners will exhaust their glycogen stores as a function of running intensity. In so doing it also provides a basis for guidelines ensuring the safety and optimizing the performance of endurance runners, both by setting personally appropriate paces and by prescribing midrace fueling requirements for avoiding ‘the wall.’ The present analysis also sheds physiologically principled light on important standards in marathon running that until now have remained empirically defined: The qualifying times for the Boston Marathon.
Author Summary
Marathon running, historically perceived as testing the physiologic limits of human endurance, has become increasingly popular even among recreational runners. Of those runners who test their endurance by racing the marathon distance, however, more than two in five report ‘hitting the wall,’ the rapid onset of severe fatigue and inability to maintain a high-intensity pace, resulting from the near-complete depletion of carbohydrate stores in the leg muscles and liver. An apparent paradox of long-distance running is that even the leanest athletes store enough fat to power back-to-back marathons, yet small carbohydrate reservoirs can nevertheless catastrophically limit performance in endurance exercise. In this study I develop and validate a mathematical model that facilitates computation of personalized estimates of the distances at which runners will exhaust their carbohydrate stores while running at selected paces. In addition, I provide a systematic approach to estimating personalized maximum speeds at which runners can safely complete a marathon, based on accessible physiologic parameters such as heart rate and running speed. This analysis provides a quantitative basis for improving the safety and optimizing the performance of endurance runners, evaluating midrace fueling requirements, and estimating limits of performance in human endurance running, for elite and recreational runners alike.
doi:10.1371/journal.pcbi.1000960
PMCID: PMC2958805  PMID: 20975938
5.  The foot in multistage ultra-marathon runners: experience in a cohort study of 22 participants of the Trans Europe Footrace Project with mobile MRI 
BMJ Open  2012;2(3):e001118.
Objectives
67 runners participated in the Trans Europe FootRace 2009 (TEFR09), a 4487 km (2789 mi) multistage ultra-marathon covering the south of Europe (Bari, Italy) to the North Cape. Reports on ultra-marathons are lacking, but the literature reports overuse injuries in athletes, especially to the Achilles tendon (AT), ankle or hind foot. Bone oedema may be related to exposure and is present in fatigue fractures. Therefore, the aim of this study was to determine prospectively if sustained maximal load during an ultra-marathon leads to damage to the foot.
Design and participants
In a cohort study, repeated scanning of the 22 athletes participating in the study was performed before and during (approximately every 1000 km) the race. Using the obtained fat saturated inversion recovery sequence, two experienced readers blinded to the clinical data rated the images regarding foot lesions. Statistical analysis included regression analysis and computation of the inter-rater reliability.
Setting
The TEFR09 course. MRI scanning was performed according to prearranged schedules for every participant, using a mobile 1.5 Tesla MRI unit on a trailer following the race.
Primary outcome measures
MRI data such as AT diameter, bone or tendon lesions, subcutaneous, plantar fascia or intraosseous oedema.
Results
The 22 study participants did not differ significantly from the total of the 67 TEFR09 runners regarding height, weight and age. The AT diameter increased significantly from 6.8 to 7.8 mm as did intraosseous signal, bone lesions and subcutaneous oedema. However, finishers differed only regarding plantar aponeurosis and subcutaneous oedema from participants aborting the TEFR09. Inter-rater reliability was 0.88–0.98.
Conclusion
Under the extreme stress of the TEFR09, an increase of the AT diameter as well as bone signal are thought to be adaptive since only subcutaneous oedema and plantar fascia oedema were related to abortion of the race.
Trial registration number
University of Ulm, Germany Ethics Committee Number 78/08-UBB/se.
Article summary
Article focus
A study on effects of ultra-marathon running, in this case, the multistage Trans Europe FootRace covering a distance of 4487 km from Bari (Italy) to the North Cape.
Observational cohort study using MRI to look for possible lesions to the foot.
Key messages
During sustained maximal load, AT diameter and bone MRI short τ inversion recovery signal (hinting at subtle oedema) increases. This is thought to be adaptive.
Subcutaneous oedema and plantar fascia signal were related to abortion of the race. These measurements seem to be related to relevant changes leading to discontinuation of the run.
No relevant new foot joint or tendon lesions were detected during the race over 4487 km.
Strengths and limitations of this study
Repeated measurement prospectively during the run was possible only because of the mobile MRI unit used for this research project.
The number of included runners (22) is high compared with other MRI-based studies but may have been too small to detect less frequent lesions.
doi:10.1136/bmjopen-2012-001118
PMCID: PMC3364457  PMID: 22619270
6.  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.
doi:10.1186/2052-1847-6-4
PMCID: PMC3896776  PMID: 24438692
Voxel based morphometry; VBM; Catabolism; Plasticity; Brain; Default mode network; MRI; Ultra marathon
7.  Do older athletes reach limits in their performance during marathon running? 
Age  2011;34(3):773-781.
In the last decades, the participation of elderly trained people in endurance events such as marathon running has dramatically increased. Previous studies suggested that the performance of master runners (> 40 yrs) during marathon running has improved. The aims of the study were : (i) to analyze the changes in participation and performance trends of master marathon runners between 1980 and 2009 and, ii) to compare the gender differences in performance as a function of age across the years. Running times of the best male and female runners between 20 and 79 yrs of age who competed in the New-York City marathon were analyzed. Gender differences in performance times were analysed for the top 10 male and female runners between 20 and 65 yrs of age. The participation of master runners increased during the 1980–2009 period, to a greater extent for females compared to males. During that period, running times of master runners significantly (P<0.01) decreased for males older than 64 yrs and for females older than 44 yrs, respectively. Gender differences in running times decreased over the last 3 decades but remained relatively stable across the ages during the last decade. These data suggest that male (≥ 65 yrs) and female (≥ 45 yrs) master runners have probably not yet reached their limits in marathon performance. The relative stability of gender differences in marathon running times across the different age groups over the last decade also suggests that age-related declines in physiological function do not differ between male and female marathoners.
doi:10.1007/s11357-011-9271-z
PMCID: PMC3337940  PMID: 21617894
Adult; Age Factors; Aged; Aging; physiology; Athletes; Exercise Tolerance; physiology; Female; Follow-Up Studies; Humans; Longevity; physiology; Male; Middle Aged; Physical Endurance; physiology; Physical Fitness; physiology; Retrospective Studies; Running; physiology; Sex Factors; Young Adult; Running; Aging; Master athletes; Endurance exercise; Gender differences
8.  Do older athletes reach limits in their performance during marathon running? 
Age  2011;34(3):773-781.
In the last decades, the participation of elderly trained people in endurance events such as marathon running has dramatically increased. Previous studies suggested that the performance of master runners (>40 years) during marathon running has improved. The aims of the study were (1) to analyze the changes in participation and performance trends of master marathon runners between 1980 and 2009, and (2) to compare the gender differences in performance as a function of age across the years. Running times of the best male and female runners between 20 and 79 years of age who competed in the New York City Marathon were analyzed. Gender differences in performance times were analyzed for the top 10 male and female runners between 20 and 65 years of age. The participation of master runners increased during the 1980–2009 period, to a greater extent for females compared to males. During that period, running times of master runners significantly (P < 0.01) decreased for males older than 64 years and for females older than 44 years, respectively. Gender differences in running times decreased over the last three decades but remained relatively stable across the ages during the last decade. These data suggest that male (≥65 years) and female (≥45 years) master runners have probably not yet reached their limits in marathon performance. The relative stability of gender differences in marathon running times across the different age groups over the last decade also suggests that age-related declines in physiological function do not differ between male and female marathoners.
doi:10.1007/s11357-011-9271-z
PMCID: PMC3337940  PMID: 21617894
Running; Aging; Master athletes; Endurance exercise; Gender differences; Life Sciences; Molecular Medicine; Geriatrics/Gerontology; Cell Biology
9.  Physiological alterations after a marathon in the first 90-year-old male finisher: case study 
SpringerPlus  2014;3:608.
Introduction
Endurance performance decreases during ageing due to alterations in physiological characteristics, energy stores, and psychological factors. To investigate alterations in physiological characteristics and body composition of elderly master athletes in response to an extreme endurance event, we present the case of the first ninety-year-old official male marathon finisher.
Case description
Before and directly after the marathon, a treadmill incremental test, dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, mechanography, and dynamometry measurements were conducted. The athlete finished the marathon in 6 h 48 min 55 s, which corresponds to an average competition speed of 6.19 km h-1.
Discussion and Evaluation
Before the marathon, was 31.5 ml min-1 kg-1 body mass and peak heart rate was 140 beats min-1. Total fat mass increased in the final preparation phase (+3.4%), while leg fat mass and leg lean mass were slightly reduced after the marathon (-3.7 and -1.6%, respectively). Countermovement jump (CMJ) peak power and peak velocity decreased after the marathon (-16.5 and -14.7%, respectively). Total impulse during CMJ and energy cost of running were not altered by the marathon. In the left leg, maximal voluntary ground reaction force (Fm1LH) and maximal isometric voluntary torque (MIVT) were impaired after the marathon (-12.2 and -14.5%, respectively).
Conclusions
Side differences in Fm1LH and MIVT could be attributed to the distinct non-symmetrical running pattern of the athlete. Similarities in alterations in leg composition and CMJ performance existed between the nonagenarian athlete and young marathon runners. In contrast, alterations in total body composition and m1LH performance were markedly different in the nonagenarian athlete when compared to his younger counterparts.
doi:10.1186/2193-1801-3-608
PMCID: PMC4210455  PMID: 25392780
Dual-energy X-ray absorptiometry; Peripheral quantitative computed tomography; Countermovement jump; Multiple one-legged hopping; Impulse
10.  The SPLASH/ICPC integrity marathon in Ibadan, Nigeria: incidence and management of injuries and marathon-related health problems 
Background
The growing interest in marathon runners and marathons in Nigeria has not been reflected in reports of injuries and other health problems associated with these events. This study therefore outlines the incidence of injuries, marathon-related health problems and delivery of physiotherapy at the maiden and second editions of the Splash 105.5 FM/ICPC Integrity Marathon in Ibadan city, south-west Nigeria in 2009 and 2010.
Methods
Using a data entry sheet, demographics and information on running experience, past and present injuries and other health problems reported en route and at the finish line by the runners were documented. The prevalence of injuries and other health problems reported by previous and first-time runners were compared.
Results
In both events, 16.3% and 17.2% of the runners respectively reported injuries with significant occurrence in first-time runners (p = 0.003 for 2009; p = 0.002 for 2010) mostly at the finish line. The reported injury type and site were muscle cramps and the thigh (39.7% and 76.4% respectively). Heat exhaustion was reported by 42.8% of runners in 2009 and 56.3% in 2010. Cryotherapy was mostly used in combination with other physiotherapy modalities in both years.
Conclusion
Most of the injuries and other health problems were reported by first-time marathon runners mainly at the finish line. The most reported site of injury was the thigh while muscle cramps and heat exhaustions were the most reported types of injuries and health problems. First-time marathon runners should be adequately informed of the predisposition to injury during marathons and adequate body conditioning should be emphasized. Ample preparation and effective involvement of the physiotherapy team is essential for management of injured runners en route and at the finish line in a marathon.
doi:10.1186/2052-1847-5-6
PMCID: PMC3674981  PMID: 24499546
Physiotherapy; Marathon; Injuries; Runners
11.  Heart Rate Recovery After Exercise and Neural Regulation of Heart Rate Variability in 30-40 Year Old Female Marathon Runners 
The aim of the present study was to examine the effects of endurance training on heart rate (HR) recovery after exercise and cardiac autonomic nervous system (ANS) modulation in female marathon runners by comparing with untrained controls. Six female marathon runners (M group) aged 32-40 years and eight age-matched untrained females (C group) performed a maximum-effort treadmill running exercise. Maximal oxygen uptake (VO2max) was measured during the exercise with a gas analyzer connected to subjects through a face mask. Heart rate, blood pressure and blood lactate were measured before and after the exercise. Rating of perceived exertion (RPE) to the exercise was obtained immediately after the exercise. Holter ECG was recorded and analyzed with power spectral analysis of heart rate variability (HRV) to investigate the cardiac ANS modulation. The M group had significantly higher VO2max, faster HR recovery after exercise, higher Mean RR, SDRR, HF power and lower LF/HF ratio at rest compared with the C group. The M group also presented greater percent decrease of blood pressure after exercise, although their blood pressure after exercise was higher than the C group. It is suggested that endurance training induced significant alterations in cardiac ANS modulation at rest and significant acceleration of HR recovery after exercise in female marathon runners. Faster HR recovery after exercise in the female marathon runners should result from their higher levels of HRV, higher aerobic capacity and exaggerated blood pressure response to exercise compared with untrained controls.
Key PointsThe effects of endurance training on HR recovery after exercise and cardiac ANS modulation were investigated in female marathon runners by comparing with untrained controls.Time and frequency domain analysis of HRV was used to investigate cardiac ANS modulation.As compared with untrained controls, the female marathon runners showed faster HR recovery after exercise, which should result from their higher levels of HRV, higher aerobic capacity and exaggerated blood pressure response to exercise.
PMCID: PMC3880089  PMID: 24431956
Heart rate recovery; heart rate variability; female marathon runner
12.  Performance and age of African and non-African runners in half- and full marathons held in Switzerland, 2000–2010 
Background
Endurance running performance of African (AF) and non-African (NAF) athletes is investigated, with better performances seen for Africans. To date, no study has compared the age of peak performance between AF and NAF runners. The present research is an analysis of the age and running performance of top AF and NAF athletes, using the hypothesis that AF athletes were younger and faster than NAF athletes.
Methods
Age and performance of male and female AF and NAF athletes in half-marathons and marathons held in Switzerland in 2000–2010 were investigated using single and multilevel hierarchical regression analyses.
Results
For half-marathons, male NAF runners were older than male AF runners (P = 0.02; NAF, 31.1 years ± 6.4 years versus AF, 26.2 years ± 4.9 years), and their running time was longer (P = 0.02; NAF, 65.3 minutes ± 1.7 minutes versus AF, 64.1 minutes ± 0.9 minutes). In marathons, differences between NAF and AF male runners in age (NAF, 33.0 years ± 4.8 years versus AF, 28.6 years ± 3.8 years; P < 0.01) and running time (NAF, 139.5 minutes ± 5.6 minutes versus AF, 133.3 minutes ± 2.7 minutes; P < 0.01) were more pronounced. There was no difference in age (NAF, 31.0 years ± 7.0 years versus AF, 26.7 years ± 6.0 years; P > 0.05) or running time (NAF, 75.0 minutes ± 3.7 minutes versus AF, 75.6 minutes ± 5.3 minutes; P > 0.05) between NAF and AF female half-marathoners. For marathoners, NAF women were older than AF female runners (P = 0.03; NAF, 31.6 years ± 4.8 years versus AF, 27.8 years ± 5.3 years), but their running times were similar (NAF, 162.4 minutes ± 7.2 minutes versus AF, 163.0 minutes ± 7.0 minutes; P > 0.05).
Conclusion
In Switzerland, the best AF male half-marathoners and marathoners were younger and faster than the NAF counterpart runners. In contrast to the results seen in men, AF and NAF female runners had similar performances. Future studies need to investigate performance and age of AF and NAF marathoners in the World Marathon Majors Series.
doi:10.2147/OAJSM.S45918
PMCID: PMC3871899  PMID: 24379724
endurance; running; ethnicity; road race; gender difference
13.  Decrease in eccentric hamstring strength in runners in the Tirol Speed Marathon 
British Journal of Sports Medicine  2006;40(10):850-852.
Background
The local muscular endurance of knee flexors, during eccentric work in particular, is important in preventing or delaying kinematic changes associated with fatigue during treadmill running. This result, however, may not be transferable to overground running.
Objective
To test the hypothesis that overground running is associated with eccentric hamstring fatigue.
Methods
Thirteen runners (12 male and one female) performed an isokinetic muscle test three to four days before and 18 hours after a marathon. Both legs were tested. The testing protocol consisted of concentric and eccentric quadriceps and hamstring contractions.
Results
There were no significant differences between peak torque before and after the race, except that eccentric peak hamstring torque (both thighs) was reduced.
Conclusion
Overground running (running a marathon) is associated with eccentric hamstring fatigue. Eccentric hamstring fatigue may be a potential risk factor for knee and soft tissue injuries during running. Eccentric hamstring training should therefore be introduced as an integral part of the training programme of runners.
doi:10.1136/bjsm.2006.028175
PMCID: PMC2465081  PMID: 16825267
fatigue; concentric; eccentric; hamstring; musculoskeletal injury
14.  Evaluating the Influence of Massage on Leg Strength, Swelling, and Pain Following a Half-Marathon 
Journal of Sports Science & Medicine  2004;3(YISI 1):37-43.
Massage therapy is commonly used following endurance running races with the expectation that it will enhance post-run recovery of muscle function and reduce soreness. A limited number of studies have reported little or no influence of massage therapy on post-exercise muscle recovery. However, no studies have been conducted in a field setting to assess the potential for massage to influence muscle recovery following an actual endurance running race. To evaluate the potential for repeated massage therapy interventions to influence recovery of quadriceps and hamstring muscle soreness, recovery of quadriceps and hamstring muscle strength and reduction of upper leg muscle swelling over a two week recovery period following an actual road running race. Twelve adult recreational runners (8 male, 4 female) completed a half marathon (21.1 km) road race. On days 1,4, 8, and 11 post-race, subjects received 30 minutes of standardized massage therapy performed by a registered massage therapist on a randomly assigned massage treatment leg, while the other (control) leg received no massage treatment. Two days prior to the race (baseline) and preceding the treatments on post-race days 1, 4, 8, and 11 the following measures were conducted on each of the massage and control legs: strength of quadriceps and hamstring muscles, leg swelling, and soreness perception. At day 1, post-race quadriceps peak torque was significantly reduced (p < 0.05), and soreness and leg circumference significantly elevated (p < 0.05) relative to pre-race values with no difference between legs. This suggested that exercise-induced muscle disruption did occur. Comparing the rate of return to baseline measures between the massaged and control legs, revealed no significant differences (p > 0.05). All measures had returned to baseline at day 11. Massage did not affect the recovery of muscles in terms of physiological measures of strength, swelling, or soreness. However, questionnaires revealed that 7 of the 12 participants perceived that the massaged leg felt better upon recovery.
Key PointsMassage does not appear to affect physiological indices of muscle recovery post exercise.Massage does appear to positively influence perceptions of recovery.More research needs to be completed on the purported benefits of massage.
PMCID: PMC3990931  PMID: 24778552
Recovery; running; perception; massage
15.  Kinematic Changes During a Marathon for Fast and Slow Runners 
The purpose of this study was to describe kinematic changes that occur during an actual marathon. We hypothesized that (1) certain running kinematic measures would change between kilometres 8 and 40 (miles 5 and 25) of a marathon and (2) fast runners would demonstrate smaller changes than slow runners. Subjects (n = 179) were selected according to finish time (Range = 2:20:47 to 5:30:10). Two high-speed cameras were used to measure sagittal-plane kinematics at kilometres 8 and 40 of the marathon. The dependent variables were stride length, contact time, peak knee flexion during support and swing, and peak hip flexion and extension during swing. Two-tailed paired t-tests were used to compare dependent variables between kilometres 8 and 40 for all subjects, and regression analyses were used to determine whether faster runners exhibited smaller changes (between miles 5 and 25) than slower runners. For all runners, every dependent variable changed significantly between kilometres 8 and 40 (p < 0.001). Stride length increased 1.3%, contact time increased 13.1%, peak knee flexion during support decreased 3.2%, and peak hip extension, knee flexion, and hip flexion during swing decreased 27.9%, increased 4.3%, and increased 7.4%, respectively (p < 0.001). Among these significant changes, all runners generally changed the same from kilometres 8 and 40 except that fast runners decreased peak knee flexion during support less than the slow runners (p < 0.002). We believe that these changes, for all runners (fast and slow), were due to fatigue. The fact that fast runners maintained knee flexion during support more consistently might be due to their condition on the race day. Strengthening of knee extensor muscles may facilitate increased knee flexion during support throughout a marathon.
Key points
Runners changed kinematics significantly from kilometres 8 to 40 (increased stride length, contact time, peak hip flexion during swing, and peak knee flexion during swing, and decreased running speed, stride frequency, peak knee flexion during support and peak hip extension during swing).
Fast runners demonstrated more peak knee flexion during support throughout a marathon.
Runners generally changed kinematics similarly (between kilometres 8 and 40) except that fast runners exhibited a more consistent peak knee flexion during support than slow runners.
Resistance training that would increase both muscular strength and endurance of knee extensors may increase peak knee flexion during support and help maintain it similar to the fast runners throughout a marathon.
PMCID: PMC3737836  PMID: 24137065
Fatigue; endurance; run; biomechanics; race
16.  Gastrointestinal disturbances in marathon runners. 
The purpose of this survey was to investigate the prevalence of running-induced gastrointestinal (GI) disturbances in marathon runners. A questionnaire was completed by 471 of the estimated 1,750 competitors in the 1986 Belfast City Marathon. Eighty-three per cent of respondents indicated that they occasionally or frequently suffered one or more GI disturbances during or immediately after running. The urge to have a bowel movement (53%) and diarrhoea (38%) were the most common symptoms, especially among female runners (74% and 68% respectively). Upper GI tract symptoms were experienced more by women than men (p less than 0.05) and more by younger runners than older runners (p less than 0.01). Women also suffered more lower GI tract symptoms than men (p less than 0.05) with younger runners showing a similar trend. Both upper and lower tract symptoms were more common during a "hard" run than an "easy" run (p less than 0.01) and were equally as common both during and after running. Of those runners who suffered GI disturbances, 72% thought that running was the cause and 29% believed their performance to be adversely affected. There was no consensus among sufferers as to the causes of symptoms and a wide variety of "remedies" were suggested. GI disturbances are common amongst long-distance runners and their aetiology is unknown. Medical practitioners should be aware of this when dealing with patients who run.
PMCID: PMC1478552  PMID: 3167507
17.  Cardiac Output and Performance during a Marathon Race in Middle-Aged Recreational Runners 
The Scientific World Journal  2012;2012:810859.
Purpose. Despite the increasing popularity of marathon running, there are no data on the responses of stroke volume (SV) and cardiac output (CO) to exercise in this context. We sought to establish whether marathon performance is associated with the ability to sustain high fractional use of maximal SV and CO (i.e, cardiac endurance) and/or CO, per meter (i.e., cardiac cost). Methods. We measured the SV, heart rate (HR), CO, and running speed of 14 recreational runners in an incremental, maximal laboratory test and then during a real marathon race (mean performance: 3 hr 30 min ± 45 min). Results. Our data revealed that HR, SV and CO were all in a high but submaximal steady state during the marathon (87.0 ± 1.6%, 77.2 ± 2.6%, and 68.7 ± 2.8% of maximal values, respectively). Marathon performance was inversely correlated with an upward drift in the CO/speed ratio (mL of CO × m−1) (r = −0.65, P < 0.01) and positively correlated with the runner's ability to complete the race at a high percentage of the speed at maximal SV (r = 0.83, P < 0.0002). Conclusion. Our results showed that marathon performance is inversely correlated with cardiac cost and positively correlated with cardiac endurance. The CO response could be a benchmark for race performance in recreational marathon runners.
doi:10.1100/2012/810859
PMCID: PMC3356747  PMID: 22645458
18.  Runners in their forties dominate ultra-marathons from 50 to 3,100 miles 
Clinics  2014;69(3):203-211.
OBJECTIVES:
This study investigated performance trends and the age of peak running speed in ultra-marathons from 50 to 3,100 miles.
METHODS:
The running speed and age of the fastest competitors in 50-, 100-, 200-, 1,000- and 3,100-mile events held worldwide from 1971 to 2012 were analyzed using single- and multi-level regression analyses.
RESULTS:
The number of events and competitors increased exponentially in 50- and 100-mile events. For the annual fastest runners, women improved in 50-mile events, but not men. In 100-mile events, both women and men improved their performance. In 1,000-mile events, men became slower. For the annual top ten runners, women improved in 50- and 100-mile events, whereas the performance of men remained unchanged in 50- and 3,100-mile events but improved in 100-mile events. The age of the annual fastest runners was approximately 35 years for both women and men in 50-mile events and approximately 35 years for women in 100-mile events. For men, the age of the annual fastest runners in 100-mile events was higher at 38 years. For the annual fastest runners of 1,000-mile events, the women were approximately 43 years of age, whereas for men, the age increased to 48 years of age. For the annual fastest runners of 3,100-mile events, the age in women decreased to 35 years and was approximately 39 years in men.
CONCLUSION:
The running speed of the fastest competitors increased for both women and men in 100-mile events but only for women in 50-mile events. The age of peak running speed increased in men with increasing race distance to approximately 45 years in 1,000-mile events, whereas it decreased to approximately 39 years in 3,100-mile events. In women, the upper age of peak running speed increased to approximately 51 years in 3,100-mile events.
doi:10.6061/clinics/2014(03)11
PMCID: PMC3935130  PMID: 24626948
Ultra-Marathon; Age of Peak Performance; Running Speed
19.  Neuromuscular Consequences of an Extreme Mountain Ultra-Marathon 
PLoS ONE  2011;6(2):e17059.
We investigated the physiological consequences of one of the most extreme exercises realized by humans in race conditions: a 166-km mountain ultra-marathon (MUM) with 9500 m of positive and negative elevation change. For this purpose, (i) the fatigue induced by the MUM and (ii) the recovery processes over two weeks were assessed. Evaluation of neuromuscular function (NMF) and blood markers of muscle damage and inflammation were performed before and immediately following (n = 22), and 2, 5, 9 and 16 days after the MUM (n = 11) in experienced ultra-marathon runners. Large maximal voluntary contraction decreases occurred after MUM (−35% [95% CI: −28 to −42%] and −39% [95% CI: −32 to −46%] for KE and PF, respectively), with alteration of maximal voluntary activation, mainly for KE (−19% [95% CI: −7 to −32%]). Significant modifications in markers of muscle damage and inflammation were observed after the MUM as suggested by the large changes in creatine kinase (from 144±94 to 13,633±12,626 UI L−1), myoglobin (from 32±22 to 1,432±1,209 µg L−1), and C-Reactive Protein (from <2.0 to 37.7±26.5 mg L−1). Moderate to large reductions in maximal compound muscle action potential amplitude, high-frequency doublet force, and low frequency fatigue (index of excitation-contraction coupling alteration) were also observed for both muscle groups. Sixteen days after MUM, NMF had returned to initial values, with most of the recovery process occurring within 9 days of the race. These findings suggest that the large alterations in NMF after an ultra-marathon race are multi-factorial, including failure of excitation-contraction coupling, which has never been described after prolonged running. It is also concluded that as early as two weeks after such an extreme running exercise, maximal force capacities have returned to baseline.
doi:10.1371/journal.pone.0017059
PMCID: PMC3043077  PMID: 21364944
20.  Rectal temperature after marathon running. 
Rectal temperature was measured in 62 male runners who competed in the 1983 Dundee marathon race: all measurements were made immediately after the race. Competitors' times were noted at 5, 10, 15 and 20 miles (8.0, 16.1, 24.1, 32.2 km) and at the finish (26.2 miles, 42.2 km). Mean finishing time of the group was 3 hr 33 min +/- 48 min (mean +/- S.D.; range = 2 hr 17 min-5 hr 11 min). Mean running speed of the group decreased progressively as the distance covered increased. Mean post-race rectal temperature was 38.7 +/- 0.9 degrees C (range 35.6-40.3 degrees C). The post-race temperature was correlated (p less than 0.01) with the time taken to cover the last 6.2 miles (10 km) of the race, but not with the overall finishing time (p greater than 0.05). Only the fastest runners were able to maintain an approximately constant pace throughout the race, whereas the slower runners slowed down progressively. The runners with the highest post-race temperature, although not necessarily the fastest runners, also tended to maintain a steady pace throughout. The runners with the lowest post-race temperature slowed down markedly only over the last 6.2 mile section of the race. The results clearly indicate that runners forced by fatigue or injury to slow down in the latter stages of races held at low ambient temperatures may already be hypothermic or at serious risk of hypothermia.
Images
PMCID: PMC1478394  PMID: 4092138
21.  Metabolic responses to a 48-h ultra-marathon run in middle-aged male amateur runners 
European Journal of Applied Physiology  2013;113(11):2781-2793.
Purpose
To evaluate ongoing metabolic changes during a 48-h competitive run and a 48-h recovery period, with focus on potential health risks exemplified by heart and skeletal muscle damage biomarkers and oxidative stress-related indices.
Methods
Blood samples were taken before the race, after 12, 24, and 48 h of running, and after 24 and 48 h of recovery from male amateur runners (N = 7, age 35–59 years, VO2max mean ± SD 57.0 ± 4.0 ml kg−1 min−1, total distance covered 183–320 km). The samples were analyzed for morphology, acid–base and electrolyte balance, iron status, lipid profile, interleukin-6, high-sensitivity C-reactive protein, N-terminal pro-brain-type natriuretic peptide, high-sensitivity cardiac troponin T, non-enzymatic antioxidants, activities of selected enzymes including antioxidant enzymes, and total antioxidant status.
Results
The sustained ultra-endurance run caused hypocapnic alkalosis with slight hyperkalemia and hypocalcemia, but no hyponatremia. Blood biochemistry showed severe muscle but not liver damage, and an acute inflammatory response. These effects were evidenced by leukocytosis, several fold rises in interleukin-6 and high sensitivity C-reactive protein, extreme elevations in serum levels of muscle enzymes, and marked increases in cardiac biomarker levels. Most of the changes dissolved during the 48 h post-race recovery. Neither the iron pool, nor erythropoiesis, nor pro-oxidant/antioxidant balance were substantially affected.
Conclusions
The changes consequent on the ultra-endurance run do not pose a serious health risk in men who begin their endeavor with ultra-endurance running in mid-life. There is some circumstantial evidence that hyperventilatory hypocapnia may modulate inflammatory response by stimulating the release of interleukin-6 from working skeletal muscles.
doi:10.1007/s00421-013-2714-8
PMCID: PMC3824198  PMID: 24002469
Ultra-marathon; Muscle damage; Inflammation; Interleukin-6; Cardiac biomarkers; Acid–base balance
22.  WEEKLY RUNNING VOLUME AND RISK OF RUNNING‐RELATED INJURIES AMONG MARATHON RUNNERS 
Purpose/Background:
The purpose of this study was to investigate if the risk of injury declines with increasing weekly running volume before a marathon race.
Methods:
The study was a retrospective cohort study on marathon finishers. Following a marathon, participants completed a web‐based questionnaire. The outcome of interest was a self‐reported running‐related injury. The injury had to be severe enough to cause a reduction in distance, speed, duration or frequency of running for at least 14 days. Primary exposure was self‐reported average weekly volume of running before the marathon categorized into below 30 km/week, 30 to 60 km/week, and above 60 km/week.
Results:
A total of 68 of the 662 respondents sustained an injury. When adjusting for previous injury and previous marathons, the relative risk (RR) of suffering an injury rose by 2.02 [95% CI: 1.26; 3.24], p < 0.01, among runners with an average weekly training volume below 30 km/week compared with runners with an average weekly training volume of 30‐60 km/week. No significant differences were found between runners exceeding 60 km/week and runners running 30‐60 km/week (RR=1.13 [0.5;2.8], p=0.80).
Conclusions:
Runners may be advised to run a minimum of 30 km/week before a marathon to reduce their risk of running‐related injury.
Level of Evidence:
2b
PMCID: PMC3625790  PMID: 23593549
Running‐related injury; marathon; risk factors; running volume.
23.  Impact of Environmental Parameters on Marathon Running Performance 
PLoS ONE  2012;7(5):e37407.
Purpose
The objectives of this study were to describe the distribution of all runners' performances in the largest marathons worldwide and to determine which environmental parameters have the maximal impact.
Methods
We analysed the results of six European (Paris, London, Berlin) and American (Boston, Chicago, New York) marathon races from 2001 to 2010 through 1,791,972 participants' performances (all finishers per year and race). Four environmental factors were gathered for each of the 60 races: temperature (°C), humidity (%), dew point (°C), and the atmospheric pressure at sea level (hPA); as well as the concentrations of four atmospheric pollutants: NO2 – SO2 – O3 and PM10 (μg.m−3).
Results
All performances per year and race are normally distributed with distribution parameters (mean and standard deviation) that differ according to environmental factors. Air temperature and performance are significantly correlated through a quadratic model. The optimal temperatures for maximal mean speed of all runners vary depending on the performance level. When temperature increases above these optima, running speed decreases and withdrawal rates increase. Ozone also impacts performance but its effect might be linked to temperature. The other environmental parameters do not have any significant impact.
Conclusions
The large amount of data analyzed and the model developed in this study highlight the major influence of air temperature above all other climatic parameter on human running capacity and adaptation to race conditions.
doi:10.1371/journal.pone.0037407
PMCID: PMC3359364  PMID: 22649525
24.  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.
doi:10.2147/IJGM.S45265
PMCID: PMC3681330  PMID: 23776392
age group; athlete; ultraendurance; running speed
25.  Lack of Awareness of Fluid Needs Among Participants at a Midwest Marathon 
Sports Health  2011;3(5):451-454.
Background:
Marathon running has become popular, particularly among inexperienced runners.
Hypothesis:
Many marathoners are inexperienced and lack concern for potential complications of marathon running.
Study Design:
Cross-sectional survey.
Methods:
In sum, 419 runners completed a survey on a variety of topics regarding training for a marathon and hydration strategies.
Results:
Overall, 211 females (38.3 ± 9.1 years old) and 208 males (41.6 ± 11.0 years old) participated. They trained for 6.8 ± 4.3 months and had run for 9.8 ± 9.1 years; 33.5% had no marathon experience and 16.9% had run 1 marathon. Of the injuries reported, 77.6% and 72.9% were minor musculoskeletal injuries during the current and previous running seasons, respectively. Of the 278 runners who had run a marathon, 54 (19.0%) had been treated in the medical tent, 31.5% of whom for dehydration. Furthermore, 54.9% and 64.3% of the survey participants were “not at all” concerned with musculoskeletal injury and hyponatremia, respectively. Also, 88.7% did not know their sweat rate; 67.8% did not weigh themselves; and 81.3% had no other method of hydration assessment. No significant correlations were found between concern for hyponatremia and age, sex, or experience.
Conclusions:
Most participants were inexperienced, lacked concern for injury or hyponatremia, and were not using methods of hydration assessment.
doi:10.1177/1941738111415043
PMCID: PMC3445216  PMID: 23016042
marathon; hydration; running; injury

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