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1.  Regionally accentuated reversible brain grey matter reduction in ultra marathon runners detected by voxel-based morphometry 
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.
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.
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.
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.
PMCID: PMC3896776  PMID: 24438692
Voxel based morphometry; VBM; Catabolism; Plasticity; Brain; Default mode network; MRI; Ultra marathon
2.  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.
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.
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).
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.
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: and
PMCID: PMC3409063  PMID: 22812450
3.  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.
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.
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.
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.
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
PMCID: PMC3566943  PMID: 23259507
body weight; brain volume; catabolism; DWI; lesion; MRI; ultramarathon
4.  Acute metabolic responses to a 24-h ultra-marathon race in male amateur runners 
European Journal of Applied Physiology  2011;112(5):1679-1688.
The study was conducted to evaluate the metabolic responses to a 24 h ultra-endurance race in male runners. Paired venous and capillary blood samples from 14 athletes (mean age 43.0 ± 10.8 years, body weight 64.3 ± 7.2 kg, VO2max 57.8 ± 6.1 ml kg−1 min−1), taken 3 h before the run, after completing the marathon distance (42.195 km), after 12 h, and at the finish of the race, were analyzed for blood morphology, acid–base balance and electrolytes, lipid profile, interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), and serum enzyme activities. Mean distance covered during the race was 168.5 ± 23.1 km (range 125.2–218.5 km). Prolonged ultra-endurance exercise triggered immune and inflammatory responses, as evidenced by a twofold increase in total leukocyte count with neutrophils and monocytes as main contributors, nearly 30-fold increase in serum IL-6 and over 20-fold rise in hsCRP. A progressive exponential increase in mean creatine kinase activity up to the level 70-fold higher than the respective pre-race value, a several fold rise in serum activities of aspartate aminotransferase and alanine aminotransferase, and a fairly stable serum γ-glutamyl transferase level, were indicative of muscle, but not of liver damage. With duration of exercise, there was a progressive development of hyperventilation-induced hypocapnic alkalosis, and a marked alteration in substrate utilization towards fat oxidation to maintain blood glucose homeostasis. The results of this study may imply that progressive decline in partial CO2 pressure (hypocapnia) that develops during prolonged exercise may contribute to increased interleukin-6 production.
PMCID: PMC3324692  PMID: 21879351
Ultra-endurance exercise; Muscle damage; Inflammatory response; Interleukin-6
5.  Marathon performance in relation to body fat percentage and training indices in recreational male runners 
The purpose of this study was to investigate the effect of anthropometric characteristics and training indices on marathon race times in recreational male marathoners.
Training and anthropometric characteristics were collected for a large cohort of recreational male runners (n = 126) participating in the Basel marathon in Switzerland between 2010 and 2011.
Among the parameters investigated, marathon performance time was found to be affected by mean running speed and the mean weekly distance run during the training period prior to the race and by body fat percentage. The effect of body fat percentage became significant as it exceeded a certain limiting value; for a relatively low body fat percentage, marathon performance time correlated only with training indices.
Marathon race time may be predicted (r = 0.81) for recreational male runners by the following equation: marathon race time (minutes) = 11.03 + 98.46 exp(−0.0053 mean weekly training distance [km/week]) + 0.387 mean training pace (sec/km) + 0.1 exp(0.23 body fat percentage [%]). The marathon race time results were valid over a range of 165–266 minutes.
PMCID: PMC3871414  PMID: 24379719
endurance; exercise; anthropometry
6.  Half-Marathon and Full-Marathon Runners' Hydration Practices and Perceptions 
Journal of Athletic Training  2011;46(6):581-591.
The behaviors and beliefs of recreational runners with regard to hydration maintenance are not well elucidated.
To examine which beverages runners choose to drink and why, negative performance and health experiences related to dehydration, and methods used to assess hydration status.
Cross-sectional study.
Marathon registration site.
Patients or Other Participants:
Men (n = 146) and women (n = 130) (age = 38.3 ± 11.3 years) registered for the 2010 Little Rock Half-Marathon or Full Marathon.
A 23-item questionnaire was administered to runners when they picked up their race timing chips.
Main Outcome Measure(s):
Runners were separated into tertiles (Low, Mod, High) based on z scores derived from training volume, expected performance, and running experience. We used a 100-mm visual analog scale with anchors of 0 (never) and 100 (always). Total sample responses and comparisons between tertile groups for questionnaire items are presented.
The High group (58±31) reported greater consumption of sport beverages in exercise environments than the Low (42 ± 35 mm) and Mod (39 ± 32 mm) groups (P < .05) and perceived sport beverages to be superior to water in meeting hydration needs (P < .05) and improving performance during runs greater than 1 hour (P < .05). Seventy percent of runners experienced 1 or more incidents in which they believed dehydration resulted in a major performance decrement, and 45% perceived dehydration to have resulted in adverse health effects. Twenty percent of runners reported monitoring their hydration status. Urine color was the method most often reported (7%), whereas only 2% reported measuring changes in body weight.
Greater attention should be paid to informing runners of valid techniques to monitor hydration status and developing an appropriate individualized hydration strategy.
PMCID: PMC3418934  PMID: 22488182
dehydration; sport beverages; hydration monitoring
7.  Leg skinfold thicknesses and race performance in male 24-hour ultra-marathoners 
The association of skinfold thicknesses with race performance has been investigated in runners competing over distances of ≤50 km. This study investigated a potential relation between skinfold thicknesses and race performance in male ultra-marathoners completing >50 km in 24 hours. Variables of anthropometry, training, and previous performance were related to race performance in 63 male ultra-marathoners aged 46.9 (standard deviation [SD] 10.3) years, standing 1.78 (SD 0.07) m in height, and weighing 73.3 (SD 7.6) kg. The runners clocked 146.1 (SD 43.1) km during the 24 hours. In the bivariate analysis, several variables were associated with race performance: body mass (r = −0.25); skinfold thickness at axilla (r = −0.37), subscapula (r = −0.28), abdomen (r = −0.31), and suprailiaca (r = −0.30); the sum of skinfold thicknesses (r = −0.32); percentage body fat (r = −0.32); weekly kilometers run (r = 0.31); personal best time in a marathon (r = −0.58); personal best time in a 100-km ultra-run (r = −0.31); and personal best performance in a 24-hour run (r = 0.46). In the multivariate analysis, no anthropometric or training variable was related to race performance. In conclusion, in contrast to runners up to distances of 50 km, skinfold thicknesses of the lower limbs were not related to race performance in 24-hour ultra-marathoners.
PMCID: PMC3069518  PMID: 21566757
8.  Changes in thioredoxin concentrations: an observation in an ultra-marathon race 
Changes in plasma thioredoxin (TRX) concentrations before, during, and after a 130-km endurance race were measured with the aim of elucidating the relationship between exercise and oxidative stress (OS).
Blood samples were taken from 18 runners participating in a 2-day-long 130-km ultra-marathon during the 2 days of the race and for 1 week thereafter. There were six sampling time points: at baseline, after the goal had been reached on the first and second day of the endurance race, respectively, and on 1, 3, and 5/6 days post-endurance race. The samples were analyzed for plasma TRX concentrations, platelet count, and blood lipid profiles.
Concentrations of plasma TRX increased from 17.9 ± 1.2 ng/mL (mean ± standard error of the mean) at baseline to 57.3 ± 5.0 ng/mL after the first day’s goal had been reached and to 70.1 ± 6.9 ng/mL after the second day's goal had been reached; it then returned to the baseline level 1 day after the race. Platelet counts of 21.3 ± 1.2 × 104 cell/μL at baseline increased to 23.9 ± 1.5 × 104 cells/μL on Day 1 and to 26.1 ± 1.0 × 104 cells/μL on Day 2. On Day 7, the platelet counts had fallen to 22.1 ± 1.2 × 104 cell/μL. There was a significant positive correlation between plasma TRX and platelet count.
These data suggest that plasma TRX is an OS marker during physical exercise. Further studies are needed to determine the appropriate level of exercise for the promotion of health.
PMCID: PMC2854340  PMID: 19960374
Lipid profile; Marathon runner; Oxidative stress; Platelet counts; Thioredoxin
9.  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
PMCID: PMC3566949  PMID: 23259535
cerebral atrophy; exercise behavior; fatigue; overload; plasticity; running
The purpose of this study was to investigate if the risk of injury declines with increasing weekly running volume before a marathon race.
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.
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).
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:
PMCID: PMC3625790  PMID: 23593549
Running‐related injury; marathon; risk factors; running volume.
11.  Rate of cardiac arrhythmias and silent brain lesions in experienced marathon runners: rationale, design and baseline data of the Berlin Beat of Running study 
Regular exercise is beneficial for cardiovascular health but a recent meta-analysis indicated a relationship between extensive endurance sport and a higher risk of atrial fibrillation, an independent risk factor for stroke. However, data on the frequency of cardiac arrhythmias or (clinically silent) brain lesions during and after marathon running are missing.
Methods/ Design
In the prospective observational “Berlin Beat of Running” study experienced endurance athletes underwent clinical examination (CE), 3 Tesla brain magnetic resonance imaging (MRI), carotid ultrasound imaging (CUI) and serial blood sampling (BS) within 2-3 days prior (CE, MRI, CUI, BS), directly after (CE, BS) and within 2 days after (CE, MRI, BS) the 38th BMW BERLIN-MARATHON 2011. All participants wore a portable electrocardiogram (ECG)-recorder throughout the 4 to 5 days baseline study period. Participants with pathological MRI findings after the marathon, troponin elevations or detected cardiac arrhythmias will be asked to undergo cardiac MRI to rule out structural abnormalities. A follow-up is scheduled after one year.
Here we report the baseline data of the enrolled 110 athletes aged 36-61 years. Their mean age was 48.8 ± 6.0 years, 24.5% were female, 8.2% had hypertension and 2.7% had hyperlipidaemia. Participants have attended a mean of 7.5 ± 6.6 marathon races within the last 5 years and a mean of 16 ± 36 marathon races in total. Their weekly running distance prior to the 38th BMW BERLIN-MARATHON was 65 ± 17 km. Finally, 108 (98.2%) Berlin Beat-Study participants successfully completed the 38th BMW BERLIN-MARATHON 2011.
Findings from the “Berlin Beats of Running” study will help to balance the benefits and risks of extensive endurance sport. ECG-recording during the marathon might contribute to identify athletes at risk for cardiovascular events. MRI results will give new insights into the link between physical stress and brain damage.
Trial registration NCT01428778
PMCID: PMC3458995  PMID: 22938148
Marathon running; ECG-recording; Magnetic resonance imaging; Blood sampling; Cardiac arrhythmia
12.  Factors associated with menstrual dysfunction and self‐reported bone stress injuries in female runners in the ultra‐ and half‐marathons of the Two Oceans 
British Journal of Sports Medicine  2007;41(10):679-683.
To investigate factors associated with menstrual dysfunction, self‐reported bone stress injuries and energy balance in women runners.
613 runners were randomly sampled during the registration period for an endurance event. Demographic information, including self‐reported height and weight, training and injury history and menstrual history, was collected by questionnaire.
Ultra‐marathon (ULTRA) participants (n = 276) were significantly older (mean (SD) 39 (8.2) vs 34 (10.5) years; p<0.001), lighter (58.2 (6.6) vs 59.6 (8.3) kg; p<0.05) and reported a higher training volume (p<0.001) than half‐marathon (HALF) participants (n = 337). Significantly more ULTRA subjects than HALF subjects reported a previous bone stress injury (21% vs 14%; p<0.05). There was no difference between the groups for menstrual status, but age at menarche was later (p<0.01) in the ULTRA group. Data were combined according to the absence (REG; n = 368/602 (61%)) or presence (IRREG; n = 234/602 (39%)) of a history of menstrual irregularity. Subject morphology was similar between groups, but the IRREG group had a higher self‐reported measure on the self‐loathing subscale (SLSS; p<0.01). The whole group was then classified according to current menstrual status, with 165 women being classified as currently irregular. (OLIGO/AMEN; 11.6%) and 445 women as currently regular (EUMEN; 88.4%). There were no morphological differences between the groups, however the OLIGO/AMEN group had a later age of menarche (p<0.01) than the EUMEN group. Further, women who reported a previous bone stress injury had higher SLSS scores than those who did not (2.91 (0.98) vs 2.68 (0.84); p<0.05).
There may be two independent mechanisms associated with energy balance, which are related to bone stress injuries, but may not necessarily be related to menstrual dysfunction.
PMCID: PMC2465157  PMID: 17496067
female; athlete; menstrual dysfunction; bone; energy balance
13.  Incidence of injuries and other health problems in the Auckland Citibank marathon, 1993. 
OBJECTIVE: To describe the incidence of injuries and other health problems sustained during participation in a marathon. METHODS: A cohort study was undertaken involving the 1993 Auckland Citibank marathon participants. Demographic data and information on injuries and other health problems sustained during, immediately after, and 7 d following the marathon were obtained from a pre-race questionnaire, the medical aid posts, and a post-race questionnaire. RESULTS: Of the 1219 starters, 916 (75.1%) completed both questionnaires. Seventy five individuals (6.2%) sought assistance at the medical aid posts. During or immediately after the marathon, 283 systemic health problems were reported by 218 respondents (23.8%) and 2671 specific health problems were reported by 846 respondents (92.4%). In the 7 d following the marathon, 1905 specific health problems were reported by 723 respondents (79.2%). The majority of the specific health problems were blisters, stiffness, and pain, predominantly involving the lower limbs. CONCLUSIONS: Although a high proportion of participants experienced health problem during the race, very few of these problems were serious. Many of the entrants were still experiencing problems 7 d after the marathon.
PMCID: PMC1332418  PMID: 9015595
14.  Risk factors for injuries and other health problems sustained in a marathon 
OBJECTIVES: To identify risk factors for injuries and other health problems occurring during or immediately after participation in a marathon. METHODS: A prospective cohort study was undertaken of participants in the 1993 Auckland Citibank marathon. Demographic data, information on running experience, training and injuries, and information on other lifestyle factors were obtained from participants before the race using an interviewer-administered questionnaire. Information on injuries and other health problems sustained during or immediately after the marathon were obtained by a self administered questionnaire. Logistic regression analyses were undertaken to identify significant risk factors for health problems. RESULTS: This study, one of only a few controlled epidemiological studies that have been undertaken of running injuries, has identified a number of risk factors for injuries and other health problems sustained in a marathon. Men were at increased risk of hamstring and calf problems, whereas women were at increased risk of hip problems. Participation in a marathon for the first time, participation in other sports, illness in the two weeks before the marathon, current use of medication, and drinking alcohol once a month or more, were associated with increased self reported risks of problems. While increased training seemed to increase the risk of front thigh and hamstring problems, it may decrease the risk of knee problems. There are significant but complex relations between age and risk of injury or health problem. CONCLUSIONS: This study has identified certain high risk subjects and risk factors for injuries and other health problems sustained in a marathon. In particular, subjects who have recently been unwell or are taking medication should weigh up carefully the pros and cons of participating. 

PMCID: PMC1756136  PMID: 10027053
15.  Creatine kinase elevations in marathon runners: relationship to training and competition. 
Elevation of creatine kinase (CK) in serum after exertion is a reliable marker of skeletal muscle injury. Limited data exist on CK levels in conditioned athletes after endurance training and competition. Serum CK was measured by a kinetic UV method (normal < 100 U/L) in 15 long distance runners before (pre-race), 24 hours after (post-race) and four weeks following (post-race) the 1979 Boston Marathon. CK levels were elevated throughout the study. Mean values for all runners and for those finishing before and after three hours and 30 minutes are as follows: Post-race CK was significantly elevated among the ten faster as compared to the five slower runners (p = 0.025). Elevations of creatine kinase drawn 24 hours post-marathon are inversely related to finishing times among the runners tested.
PMCID: PMC2595821  PMID: 7445533
16.  Analysis of performance and age of the fastest 100-mile ultra-marathoners worldwide 
Clinics  2013;68(5):605-611.
The performance and age of peak ultra-endurance performance have been investigated in single races and single race series but not using worldwide participation data. The purpose of this study was to examine the changes in running performance and the age of peak running performance of the best 100-mile ultra-marathoners worldwide.
The race times and ages of the annual ten fastest women and men were analyzed among a total of 35,956 finishes (6,862 for women and 29,094 for men) competing between 1998 and 2011 in 100-mile ultra-marathons.
The annual top ten performances improved by 13.7% from 1,132±61.8 min in 1998 to 977.6±77.1 min in 2011 for women and by 14.5% from 959.2±36.4 min in 1998 to 820.6±25.7 min in 2011 for men. The mean ages of the annual top ten fastest runners were 39.2±6.2 years for women and 37.2±6.1 years for men. The age of peak running performance was not different between women and men (p>0.05) and showed no changes across the years.
These findings indicated that the fastest female and male 100-mile ultra-marathoners improved their race time by ∼14% across the 1998–2011 period at an age when they had to be classified as master athletes. Future studies should analyze longer running distances (>200 km) to investigate whether the age of peak performance increases with increased distance in ultra-marathon running.
PMCID: PMC3654294  PMID: 23778421
Running; Ultra-Endurance; Sex Difference; Athlete
17.  An increased fluid intake leads to feet swelling in 100-km ultra-marathoners - an observational field study 
An association between fluid intake and changes in volumes of the upper and lower limb has been described in 100-km ultra-marathoners. The purpose of the present study was (i) to investigate the association between fluid intake and a potential development of peripheral oedemas leading to an increase of the feet volume in 100-km ultra-marathoners and (ii) to evaluate a possible association between the changes in plasma sodium concentration ([Na+]) and changes in feet volume.
In seventy-six 100-km ultra-marathoners, body mass, plasma [Na+], haematocrit and urine specific gravity were determined pre- and post-race. Fluid intake and the changes of volume of the feet were measured where the changes of volume of the feet were estimated using plethysmography.
Body mass decreased by 1.8 kg (2.4%) (p < 0.0001); plasma [Na+] increased by 1.2% (p < 0.0001). Haematocrit decreased (p = 0.0005). The volume of the feet remained unchanged (p > 0.05). Plasma volume and urine specific gravity increased (p < 0.0001). Fluid intake was positively related to the change in the volume of the feet (r = 0.54, p < 0.0001) and negatively to post-race plasma [Na+] (r = -0.28, p = 0.0142). Running speed was negatively related to both fluid intake (r = -0.33, p = 0.0036) and the change in feet volume (r = -0.23, p = 0.0236). The change in the volume of the feet was negatively related to the change in plasma [Na+] (r = -0.26, p = 0.0227). The change in body mass was negatively related to both post-race plasma [Na+] (r = -0.28, p = 0.0129) and running speed (r = -0.34, p = 0.0028).
An increase in feet volume after a 100-km ultra-marathon was due to an increased fluid intake.
PMCID: PMC3366912  PMID: 22472466
Fluid intake; Peripheral oedemas; Sodium; Hydrations status; Ultra-marathon
18.  Effect of Ultra-marathon (308 km) Race on Bone Metabolism and Cartilage Damage Biomarkers 
To evaluate the potential effects of a 308-km ultra-marathon on bone and cartilage biomarkers.
Venous blood samples were collected at pre-race, 100 km, 200 km, and 308 km checkpoints. The following markers of cartilage damage and bone metabolism were studied: osteocalcin (OC), osteoprotegerin (OPG), and calcium, phosphorous, and cartilage oligomeric matrix protein (COMP).
Blood samples were taken from 20 male runners at four different checkpoints. Serum COMP was increased by 194.1% (130.7% at 100 km and 160.4% at 200 km). Serum OPG was significantly increased by 158.57% at 100 km and 114.1% at 200 km compared to the pre-race measures. OC was transiently suppressed at 200 km. Serum calcium and phosphorous concentrations decreased compared to the pre-race measures.
This study showed that the 308-km ultra-marathon induced several changes, including transient uncoupling of bone metabolism, increased bone resorption, suppressed bone formation, and bone turnover and had a major impact on cartilage structure.
PMCID: PMC3309329  PMID: 22506239
Ultra-marathon; Osteoprotegerin; COMP; Osteocalcin
19.  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.
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
20.  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.
PMCID: PMC3337940  PMID: 21617894
Running; Aging; Master athletes; Endurance exercise; Gender differences; Life Sciences; Molecular Medicine; Geriatrics/Gerontology; Cell Biology
21.  Gastrointestinal Symptoms of Marathon Runners 
Western Journal of Medicine  1984;141(4):481-484.
A survey of 707 participants in the 13th Annual Trail's End Marathon in Seaside, Oregon, showed a high incidence of gastrointestinal disturbances, predominantly of the lower tract, associated with long-distance running. The urge to defecate, both during and immediately after running, occurred in over a third of runners. Bowel movements (35%) and diarrhea (19%) were relatively common after running, and runners occasionally interrupted hard runs or races for bowel movements (18%) or diarrhea (10%). Lower gastrointestinal disturbances were more frequent in women than in men and in younger than in older runners. Awareness of the frequency and nature of gastrointestinal symptoms documented by this survey will assist physicians in evaluating abdominal complaints in runners.
PMCID: PMC1021858  PMID: 6506684
22.  Grouping of runners during marathon competition. 
Marathon runners tend to form clusters during competition, possibly as a means of improving their performance. Studies of international competitors in Fukuoka and Tokyo races have shown a density of 0.44 to 0.80 runners.m2 among those maintaining a pace of 4.8-5.6 m.s-1, clustering being most marked among elite performers. Some 95% of clustered runners maintained a minimum distance of 0.5-1.5 m from other competitors; moreover, such competitors avoided occupying an angle of +/- 15 degrees either before or behind other runners. The phenomenon merits closer study by those interested in the bettering of marathon performance.
PMCID: PMC1478474  PMID: 3435819
23.  The elite marathon runner: problems during and after competition. 
Two questionnaires were given to the participants of the Danish national marathon championship to obtain information on health, training habits, previous injuries and the medical problems sustained during and after the competition. All 60 participants replied to both questionnaires. The elite runner is training between 90-150 km per week, using one daily training session. He is generally careful about stretching and warming up and down. Forty-three per cent of runners sustained injuries in the last year that prevented them from training, but only 3% needed to stay off work. The most common reasons for not completing the race were exhaustion and injuries to the lower extremities. Sixty-one per cent of the runners who did not drink at all refreshment stations dropped out, whereas only 27% of those who did dropped out. There was no difference in relation to results or medical problems between the group who used a special diet before the run and those who did not. The major medical problems were gastrointestinal disturbances, skin lesions and pain or cramps in the lower extremities. No serious injuries were reported.
PMCID: PMC1478503  PMID: 3370397
24.  Gastrointestinal disturbances in marathon runners. 
To determine the prevalence of various gastrointestinal disturbances related to long-distance running and its effect on weight, diet and everyday digestive problems, we gave a questionnaire to 279 leisure-time marathon runners, comprising 10% of the participants in a local marathon race. Their answers disclosed a prevalence of dietary changes, weight reduction and altered bowel habits (mainly looser stools and/or more frequent defaecation) of 37, 38 and 48% respectively. A quarter reported earlier long lasting gastrointestinal problems, which improved in 41% of the runners after they started regular training. Thirty-four percent experienced gastrointestinal disturbances during or after running, 20% to such an extent that it seriously affected their performance.
PMCID: PMC1478906  PMID: 2097027
25.  Marathon finishers and pre-race drop-outs. 
The purpose of this longitudinal questionnaire study was to investigate the effects of participation or non participation in a marathon race on future running behaviour. The majority (70 per cent) of the participants who intended to run a future marathon actually did so and only 11 per cent stopped running altogether. Fewer of the pre-race drop-outs (31 per cent) who indicated their intention to run a future marathon actually did so (P less than 0.001) and more of them (24 per cent) stopped running altogether (P less than 0.001) compared with the runners in the finishers' sample. These results suggest that the experience of running in a marathon does not negatively influence future running habits. However, failure to run in a race for which an entry has been made may lead to a reduced involvement in running. The present study also examined the reasons for pre-race drop-out. Injury (36 per cent), lack of training (31 per cent) and illness (12 per cent) were the most frequently given reasons for drop-out. Few differences were found between the pre-race drop-outs and the finishers, but the drop-outs did feel that running was less important (P less than 0.001), reported a greater number of longer term injuries (P less than 0.001) and did significantly less training (P less than 0.001) than the finishers.
PMCID: PMC1478627  PMID: 2605449

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