10-km Race Research Articles

Analysis of over 1 million race records shows runners from East African countries as the fastest in 50-km ultra-marathons

The 50-km ultra-marathon is a popular race distance, slightly longer than the classic marathon distance. However, little is known about the country of affiliation and age of the fastest 50-km ultra-marathon runners and where the fastest races are typically held. Therefore, this study aimed to investigate a large dataset of race records for the 50-km distance race to identify the country of affiliation and the age of the fastest runners as well as the locations of the fastest races. A total of 1,398,845 50-km race records (men, n = 1,026,546; women, n = 372,299) were analyzed using both descriptive statistics and advanced regression techniques. This study revealed significant trends in the performance of 50-km ultra-marathoners. The fastest 50-km runners came from African countries, while the fastest races were found to occur in Europe and the Middle East. Runners from Ethiopia, Lesotho, Malawi, and Kenya were the fastest in this race distance. The fastest 50-km racecourses, providing ideal conditions for faster race times, are in Europe (Luxembourg, Belarus, and Lithuania) and the Middle East (Qatar and Jordan). Surprisingly, the fastest ultra-marathoners in the 50-km distance were found to fall into the age group of 20–24 years, challenging the conventional belief that peak ultra-marathon performance comes in older age groups. These findings contribute to a better understanding of the performance models in 50-km ultra-marathons and can serve as valuable insights for runners, coaches, and race organizers in optimizing training strategies and racecourse selection.

BLOOD BIOCHEMICAL CHANGES AFTER DRAMATIC INCREASE IN RUNNING TRAINING VOLUME: EXPLORATORY STUDY IN 3 ELITE SOLDIERS

Ultra-Endurance running training is a powerful stressor for all biological systems and depends mainly on its volume and intensity. Although the high physical demands, soldiers are an unstudied group and information on exercise indicators are essential. This study aimed to observe the changes in serum biochemical indicators in previously endurance trained elite soldiers after a 17-week training program with a dramatic increase in running volume. Three subjects (#1: 26 years, 169,5cm; #2: 27 years, 167,9cm; #3: 27 years, 180,7cm) running daily between 10-12 km/day, increased their running volume to prepare the participation in a 100-km ultramarathon race. For 17 weeks the training program included 10-12 sessions per week, corresponding to 200-260 km. Average daily running volume was 35.8±6.2 km. Blood samples were taken for analysis of urea, creatinine, glucose, cholesterol and triglycerides, AST, ALT, CK, aldolase, Na, chloride, P, Ca, K, Fe, Mg and cortisol. Despite a marked drop in iron and a rise in phosphorus, the overall mineral status remained within laboratory reference values. ALT, AST, Aldolase showed slight changes while a marked increase was found in CK. Creatinine decreased and urea maintained the high starting values. Changes of glucose, cholesterol and triglycerides had no clinical significance. After the 17-week the cortisol increased to outside of the reference values in two participants. This study shows that a dramatic increase in running training volume experienced by previous trained runners is mainly reflected in basal blood chemistry through the reduction of iron and creatinine and increase of cortisol.

Prediction of performance in a 100-km run from a simple equation.

This study aimed to identify predictive variables of performance for a 100-km race (Perf100-km) and develop an equation for predicting this performance using individual data, recent marathon performance (Perfmarathon), and environmental conditions at the start of the 100-km race. All runners who had performed official Perfmarathon and Perf100-km in France, both in 2019, were recruited. For each runner, gender, weight, height, body mass index (BMI), age, the personal marathon record (PRmarathon), date of the Perfmarathon and Perf100-km, and environmental conditions during the 100-km race (i.e., minimal and maximal air temperatures, wind speed, total amount of precipitation, relative humidity and barometric pressure) were collected. Correlations between the data were examined, and prediction equations were then developed using stepwise multiple linear regression analyses. Significant bivariate correlations were found between Perfmarathon (p<0.001, r = 0.838), wind speed (p<0.001, r = -0.545), barometric pressure (p<0.001, r = 0.535), age (p = 0.034, r = 0.246), BMI (p = 0.034, r = 0.245), PRmarathon (p = 0.065, r = 0.204) and Perf100-km in 56 athletes The, 2 prediction equations with larger sample (n = 591) were developed to predict Perf100-km, one including Perfmarathon, wind speed and PRmarathon (model 1, r² = 0.549; standard errors of the estimate, SEE = 13.2%), and the other including only Perfmarathon and PRmarathon (model 2, r² = 0.494; SEE = 14.0%). Perf100-km can be predicted with an acceptable level of accuracy from only recent Perfmarathon and PRmarathon, in amateur athletes who want to perform a 100 km for the first time.

Comparison of the differences in iron and anemia-related markers by ultramarathon distance.

Iron and anemia-related markers in long-distance runners have mostly been investigated following single distance marathons, with contradictory findings. This study compared iron and anemia-related markers according to marathon distance. Iron and anemia-related markers were analyzed from blood samples of healthy, adult male (aged ≥40-60 years) long-distance runners before and after ultramarathon races of 100 km (N.=14), 308 km (N.=14), and 622 km (N.=10). Fe, total iron-binding capacity (TIBC), unsaturated iron-binding capacity (UIBC), transferrin saturation, ferritin, high-sensitivity C-reactive protein (hs-CRP), white blood cell (WBC), red blood cell (RBC), hemoglobin (Hb), and hematocrit (Hct) levels were analyzed. On completion of all races, the iron levels and transferrin saturation decreased (P<0.05), while the ferritin and hs-CRP levels and WBC counts significantly increased (P<0.05). The Hb concentrations increased after the 100-km race (P<0.05), although the Hb levels and Hct decreased after the 308- and 622-km races (P<0.05). The highest-to-lowest levels of unsaturated iron-binding capacity were found following the 100-km, 622-km, and 308-km races, whereas those of the RBC count were found following the 622-km, 100-km, and 308-km races. Ferritin levels were significantly higher following the 308-km race than after the 100-km race (P<0.05); hs-CRP levels in the 308- and 622-km races were higher than those in the 100-km race. Ferritin levels increased due to inflammation following distance races, and runners experienced transient iron deficiency without anemia. However, the differences in iron and anemia-related markers according to the ultramarathon distance remain unclear.

Acute effects of a 60-min time trial on power-related parameters in trained endurance runners

BackgroundThe advent of power meters for running has raised the interest of athletes and coaches in new ways of assessing changes in running performance. The aim of this study is to determine the changes in power-related variables during and after a strenuous endurance running time trial.MethodsTwenty-one healthy male endurance runners, with a personal record of 37.2 ± 1.2 min in a 10-km race, completed a 1-h run on a motorized treadmill trying to cover as much distance as they could. Before and after the time trial the athletes were asked to perform a 3-min run at 12 km h−1. Normalized mean power output, step frequency, form power and running effectiveness were calculated using the Stryd™ power meter. Heart rate (HR) and rating of perceived exertion (RPE) were monitored, and data averaged every 5 min.ResultsDespite high levels of exhaustion were reached during the time trial (HRpeak = 176.5 ± 9.8 bpm; RPE = 19.2 ± 0.8), the repeated measures ANOVA resulted in no significant differences (p ≥ 0.05), between each pair of periods for any of the power-related variables. The pairwise comparison (T test) between the non-fatigued and fatigued constant 3-min runs showed an increase in step frequency (p = 0.012) and a decrease in form power (p < 0.001) under fatigue conditions, with no meaningful changes in normalized mean power output and running effectiveness.ConclusionsTrained athletes are able to maintain power output and running effectiveness during a high demanding extended run. However, they preferred to reduce the intensity of vertical impacts under fatigue conditions by increasing their step frequency.

Effects of Gradient and Speed on Uphill Running Gait Variability.

The aim of this study was to investigate the effects of gradient and speed on running variability (RV) and local dynamic stability (LDS) during uphill running. (1) Both gradient and speed increase metabolic effort, in terms of heart rate (HR) and perceived exertion (CR10), in line with the contemporary literature, and (2) gradient increases RV and impairs LDS. "Crossover" observational design. Level 3. A total of 25 runners completed 10-minute running trials in 3 different conditions and in a randomized order: gradient at 0% (0CON), 2% (2CON), and 2% at isoefficiency speed (2IES). 0CON and 2CON speeds were calculated as the "best 10-km race performance" minus 1 km·h-1, whereas 2IES speed was adjusted to induce the same metabolic expenditure as 0CON. HR and perceived exertion as well as running kinematic variables were collected across all trials and conditions. Running variability was calculated as the standard deviation of the mean stride-to-stride intervals over 100 strides, while LDS was expressed by the Lyapunov exponent (LyE) determined on running cycle time over different running conditions. Increases in HR and CR10 were observed between 0CON and 2CON (P < 0.001) and between 2IES and 2CON (P < 0.01). Higher RV was found in 2CON compared with 0CON and 2IES (both P < 0.001). Finally, the largest LyE was observed in 2IES compared with 0CON and 2CON (P = 0.02 and P = 0.01, respectively). Whereas RV seems to be dependent more on metabolic effort, LDS is affected by gradient to a greater extent. Running variability could be used to monitor external training load in marathon runners.

Older or Wiser? Age and Experience Trends in 20 Years of Olympic and World Swimming Championships Open Water 10-km Races.

The aims of the present research were to estimate the age of peak performance (APP) and to examine the role of previous experience at the world-level open water race performances. Finishing positions and age of swimmers (639 females and 738 males) in the 10-km events of World Championship (WCH) and Olympic Games (OG) from 2000 to 2019 were obtained from the official results websites. Years of previous experience were computed using the number of previous participations in WCH or OG. APP was estimated using quadratic models of the 10th percentile top race positions and resulted in 28.94 years old for males (R2 = 0.551) and 27.40 years old for females (R2 = 0.613). Regression analysis revealed an improvement of 1.36 or 8.19 finishing positions for each additional year of age or experience, respectively (R2 = 0.157). However, significant differences (p < 0.001) between age and experience showed that the swimmer’s age became less relevant for performance as years of experience increased. These results, in terms of age, are in line with other mass-start disciplines of similar duration (≈2 h) and, in terms of experience, confirm the importance of previous participation in improving tactical decision making during open water races.

Effects of nail softness and stiffness with distance running shoes on ground reaction forces and vertical loading rates in male elite long-distance runners with pronated feet

BackgroundTo improve propulsion during running, athletes often wear spike shoes designed for training and/or competition. Running with spike shoes may cause pain and/or injuries. To address this problem, a modified spike shoe was tested. This study aimed to evaluate the effects of running with dual-versus single-stiffness spike running shoes on running mechanics in long-distance runners with pronated feet.MethodsSixteen male elite (national competitive level) runners (5000 or 10,000 m) aged 28.2 ± 2.5 years with pronated feet volunteered to participate in this study. To be included, participants had to have achieved personal best race times over 5- and/or 10-km races under 17 or 34 min during official running competitions. All participants were heel strikers and had a history of 11.2 ± 4.2 years of training. For the assessment of running kinetics, a force plate was imbedded into a walkway. Running kinematics were recorded using a Vicon-motion-capture system. Nike Zoom Rival shoes (Nike, Nike Zoom Rival, USA) were selected and adapted according to spike softness and stiffness. Participants ran at a constant speed of ~4.0 m/s across the walkway with both shoe conditions in randomized order. Six trials were recorded per condition. The main outcomes included peak ground reaction forces and their time-to-peak, average and instantaneous vertical loading rates, free moments, and peak ankle eversion angles.ResultsPaired t-tests revealed significantly lower lateral (p = 0.021, d = 0.95) and vertical (p = 0.010, d = 1.40) forces at heel contact during running with dual-stiffness spike shoes. Running with dual-stiffness spike shoes resulted in a significantly longer time-to-peak vertical (p = 0.004, d = 1.40) force at heel contact. The analysis revealed significantly lower average (p = 0.005, d = 0.46) and instantaneous (p = 0.021, d = 0.49) loading rates and peak negative free moment amplitudes (p = 0.016, d = 0.81) when running with dual-stiffness spike shoes. Finally, significantly lower peak ankle eversion angles were observed with dual-stiffness spike shoes (p < 0.001, d = 1.29).ConclusionsRunning in dual- compared with single-stiffness spike distance running shoes resulted in lower loading rates, free moment amplitudes, and peak ankle eversion angles of long-distance runners with pronated feet.

Pacing in Long-Distance Running: Sex and Age Differences in 10-km Race and Marathon.

Background and objective: The recent availability of data from mass-participation running events has allowed researchers to examine pacing from the perspective of non-elite distance runners. Based on an extensive analysis of the literature, we concluded that no study utilizing mass-participation events data has ever directly compared pacing in the 10-km race, with other long-distance races. Therefore, the main aim of this study was to assess and compare pacing between 10-km runners and marathoners, in regards to their sex and age. Materials and methods: For the purpose of this study, official results from the Oslo marathon (n = 8828) and 10-km race (n = 16,315) held from 2015 to 2018 were included. Results: Both 10-km runners and marathoners showed positive pacing strategies. Moreover, two-way analysis of variance showed that women were less likely to slow in the marathon than men (9.85% in comparison to 12.70%) however, not in the 10-km race (3.99% in comparison to 3.38%). Finally, pace changing is more prominent in youngest and oldest marathoners comparing to the other age groups (12.55% in comparison to 10.96%). Conclusions: Based on these findings, practitioners should adopt different training programmes for marathoners in comparison to shorter long-distance runners.

Effects of different goal orientations and virtual opponents performance level on pacing strategy and performance in cycling time trials

ABSTRACT We investigated the effects of different performance goals (best time vs. beat the opponent) on pacing behaviour during a 10-km cycling race and explored the influence of different performance level of opponents on ratings of perceived exertion (RPE), affective feelings and self-efficacy. Thirteen cyclists performed two time-trials (TT) and two races against a faster (FAST +6%) or a slower (SLOW –3%) virtual opponent. Power output (PO), RPE, affective feelings and self-efficacy were recorded at each kilometre point. Race average and race phases [starting (P1 = first kilometre); first half (P2 = 2nd–5th kilometre); second half (P3 = 6th–9th kilometre) and final sprint (FS = last kilometre)] were analysed. There was no difference in performance, assessed by race time between conditions (p = .84). PO during TT was lower in P3 compared to FS (p = .03; ES 0.6; 90%CI 0.4–0.7). In SLOW and FAST, PO was higher in P1 compared to other phases (p < .05). PO in FS was higher in TT compared to FAST (p = .01; ES −0.97; 90%IC −1.4 to −0.5). RPE increased and affective feelings decreased during all conditions. Self-efficacy was stable through TT and SLOW, but decreased during FAST with higher values in P1 compared to P2 (p = .01; ES −1.1; 90%IC −1.6 to −0.6), P3 (p < .001; ES −2.2; 90%IC −2.8 to −1.6) and FS (p < .001; ES −2.6; 90%IC −3.3 to −1.8). Pacing behaviour, specifically starting and final sprint, was affected by virtual opponents independent of performance level, demonstrating the importance of goal orientation. Highlights Adjustments in exercise intensity result from a complex decision-making process involving physiological, psychological, environmental and tactical information. Goal pursuit is an important determinant of pacing behaviour since athletes must balance their efforts with expectations of success. A competitive environment may be included to motivate participants to maintain their effort and at the same time to improve their self-confidence. The presence of a final sprint seems to be related to the goal orientation and perceived outcomes of success or failure.

Physiological Determinants of Ultramarathon Trail-Running Performance.

The physiological determinants of ultramarathon success have rarely been assessed and likely differ in their contributions to performance as race distance increases. To examine predictors of performance in athletes who completed either a 50-, 80-, or 160-km trail race over a 20-km loop course on the same day. Measures of running history, aerobic fitness, running economy, body mass loss, hematocrit alterations, age, and cardiovascular health were examined in relation to race-day performance. Performance was defined as the percentage difference from the winning time at a given race distance, with 0% representing the fastest possible time. In the 50-km race, training volumes, cardiovascular health, aerobic fitness, and a greater loss of body mass during the race were all related to better performance (all P < .05). Using multiple linear regression, peak velocity achieved in the maximal oxygen uptake test (β = -11.7, P = .002) and baseline blood pressure (β = 3.1, P = .007) were the best performance predictors for the men's 50-km race (r = .98, r2 = .96, P < .001), while peak velocity achieved in the maximal oxygen uptake test (β = -13.6, P = .001) and loss of body mass (β = 12.8, P = .03) were the best predictors for women (r = .94, r2 = .87, P = .001). In the 80-km race, only peak velocity achieved in the maximal oxygen uptake test predicted performance (β = -20.3, r = .88, r2 = .78, P < .001). In the 160-km race, there were no significant performance determinants. While classic determinants of running performance, including cardiovascular health and running fitness, predict 50-km trail-running success, performance in longer-distance races appears to be less influenced by such physiological parameters.

Carbohydrate supplementation during a simulated 10-km open water swimming race: effects on physiological, perceptual parameters and performance.

ABSTRACT The aim of the present study was to test the effect of carbohydrate ingestion, simulating a 10-km open water race competition on energy cost (Csw), perceived exertion (RPE), heart rate (HR), stroke rate (SR) and performance. We hypothesized that carbohydrate ingestion would reduce Csw and RPE in elite open water swimmers (OW-swimmers) and improve performance. Eight elite OW-swimmers swam for 3 × 30 min with 20-s of interval necessary to collect data in the swimming flume at a pre-set pace corresponding to their 10-km race pace, followed by a time to exhaustion test (TTE) at 100% of the peak oxygen uptake (V̇O2peak). During the set, OW-swimmers ingested 45-g of carbohydrates (CHO) in 550-mL of water (8% solution) during each of the two intervals or a placebo solution (PLA). HR, RPE, V̇O2 and SR were measured. Shapiro–Wilk test was used to verify the normal distribution of data. Two-way repeated measures ANOVA and t-test was performed (p < 0.05). A significant difference emerged in TTE between the trials (169.00 ± 91.06 s in CHO; 102.31 ± 57.47 s in PLA). HR, RPE and SR increased during the TTE but did not differ between trials. Csw did not show a significant main effect between the two conditions and in time course in both conditions. CHO ingestion significantly increased TTE at 100% of V̇O2peak after 90-min of swimming at 10-km race pace. These findings indicate that CHO intake during a 10-km open water swimming competition should have a beneficial impact on performance in the final part of the race.

Association between dietary practice, body composition, training volume and sport performance in 100-Km elite ultramarathon runners

Sport performance during competitions is a central goal for athletes, and several factors have been identified that appear to have an association with better performance in different sport disciplines. However, the data are still not conclusive in ultramarathon runners. Accordingly, this study aimed to assess the potential associations between anthropometric, body composition, dietary and training factors and athletic performance in 100-Km elite ultramarathon runners. Body mass index (BMI), body composition, training volume, Mediterranean dietary adequacy score (MDAS) and "100-Km race competition record" were assessed in 10 elite ultramarathon runners from the Italian Ultramarathon and Trail Association (IUTA) of the Italian national team. The study sample had a mean age of 41.1±7.59 years and BMI of 21.66±1.11kg/m2. Female athletes had a lower appendicular skeletal muscle index (ASMI) and 100-Km race competition record, and a higher trunk fat percentage and MDAS compared to males. Correlation analysis revealed a significant association between the 100-Km race competition record and age, gender, ASMI, training volume, total body and trunk fat percentages. However, after correcting for confounders, partial correlation analysis confirmed only the association between training volume and 100-Km race competition record (ρ=-0.891, p=0.009). Our findings provide evidence that a higher training volume expressed as Kilometers per week is an independent variable associated with better performance in 100-Km race competitions in elite ultramarathon runners. Future studies are needed to assess the usefulness of programs based on the increase of training volume as a strategy to improve athletic performance in 100-Km races in this specific population.

Effects of 100-km ultramarathon on erythropoietin variation in runners with hepatitis B virus carrier.

Completing an ultramarathon leads to an immediate postrace surge of erythropoietin (EPO). Patients with chronic liver disease may have high plasma EPO concentrations. This study aims to explore whether plasma EPO concentrations vary between hepatitis B virus carrier (HBVc) and non-HBVc runners during long distance running. Blood samples were collected from 8 HBVc and 18 non-HBVc runners at 3 different time points: 1 week before, immediately following, and then 24 h after the 100-km ultramarathon race. Samples were analyzed for plasma EPO levels. EPO concentration had a statistically significant rise immediately after the race (8.7 [7.1-11.9] mU·mL-1 to 23.7 [14.8-37.2] mU·mL-1, P < 0.001) and maintained the high levels 24 h after the race finished (16.7 [11.5-21.0] mU·mL-1, P < 0.001) in all participants. The mean of EPO concentration was 8.9 (5.7-13.2) mU·mL-1 in HBVc runners and was 8.7 (7.7-11.2) mU·mL-1 in non-HBVc runners in the prerace. In HBVc runners, plasma EPO levels were no different at baseline (P = 0.657) and increased in the same fashion in response to ultramarathon compared with non-HBVc runners. Plasma EPO levels between the two groups were not statistically different at any time point. Prolonged endurance exercise led to a significant increase in EPO. A comparable increase in EPO levels was observed in HBVc and non-HBVc runners during and 24 h after 100-km ultramarathon. However, a small sample size might have affected the ability to detect a difference if it does exist.

Changes in immunological parameters in ultramarathon runners depending on the duration of the load.

In recent decades, there has been an increasing interest in long-distance running, not only to the classic marathon distances but also to an ultramarathon -100 km, 250 km, and multi-day races. One of the most reactive body systems in conditions of prolonged muscular loads is the immune system. The work aimed to investigate the changes in immunological parameters in runners for extra-long distances of various durations. We examined 73 male athletes specializing in long-distance and ultra-long-distance running. The design of the survey included the study of immunological status during the marathon race, 100 km run, and six-day run. We studied the dynamics of leukocyte formula; subpopulations of lymphocytes; fractions of immunoglobulins: IgA, IgM, IgG; phagocytic activity. During the marathon run, athletes' immunological changes are manifested by the development of neutrophilic leukocytosis with a decrease in the phagocytic activity of neutrophils. There was a sharp increase in the NLR and decrease in the LMR. A 100-km race caused a decrease in the absolute and relative number of T-lymphocytes. NLR increased almost ten times, and LMR, on the contrary, decreased nearly five times. On the first day of the 6-days run, there is a sharp increase in NLR and a decrease in LMR, after which there is a relative stabilization of both indicators. Changes in immunological parameters during jogging are closely related to the duration of the load. The most pronounced changes are observed on the part of neutrophils and lymphocytes.

Vascular Function Is Differentially Altered by Distance after Prolonged Running.

Ultraendurance exercise is steadily growing in popularity; however, the effect of increasingly prolonged durations of exercise on the vascular endothelium is unknown. The aim of this study was to characterize the effect of various ultramarathon running distances on vascular form and function. We evaluated vascular endothelial function via flow-mediated dilation (FMD) in the superficial femoral artery, as well as microvascular function, inflammatory factors, and central artery stiffness, before and after participants completed 25-km (7M:2F), 50-km (11M:10F), 80-km (9M:4F), or 160-km (9M:2F) trail races all run on the same day and course. Completion required 149 ± 20, 386 ± 111, 704 ± 130, and 1470 ± 235 min, with corresponding average paces of 6.0 ± 0.8, 7.7 ± 2.2, 8.6 ± 1.3, and 9.6 ± 1.3 min·km-1, respectively. At baseline, there were no differences in participant characteristics across race distance groups. Shear rate stimulus trended toward an increase after the race (P = 0.07), but resting postrace artery diameter (P < 0.001) was elevated to a similar extent in all conditions. There was a reduction in FMD after the 50-km race (Δ -1.9% ± 2.2%, P < 0.01), but not the 25-km (Δ +0.3% ± 2.9%, P = 0.8), the 80-km (Δ -1.5% ± 3.2%, P = 0.1), or the 160-km (Δ +0.5% ± 2.5%, P = 0.5) race. Inflammatory markers increased most after 160 km, but arterial stiffness and microvascular function were not differently affected by race distance. Although the superficial femoral artery baseline diameter was larger postexercise regardless of race distance, only the 50-km race reduced FMD, whereas a short-duration higher-intensity race (25 km) and longer-duration lower-intensity races (160 km) did not. Therefore, a 50-km ultramarathon may represent the intersection between higher-intensity exercise over a prolonged duration, causing reduced endothelial function not seen in shorter or longer distances.

Exercise dose affects the circulating microRNA profile in response to acute endurance exercise in male amateur runners.

The systemic response to exercise is dose-dependent and involves a complex gene expression regulation and cross-talk between tissues. This context ARISES the need for analyzing the influence of exercise dose on the profile of circulating microRNAs (c-miRNAs), as emerging posttranscriptional regulators and intercellular communicators. Thus, we hypothesized that different exercise doses will determine specific c-miRNA signatures that will highlight its potential as exercise dose biomarker. Nine active middle-aged males completed a 10-km race (10K), a half-marathon (HM), and a marathon (M). Blood samples were collected immediately before and after races. Plasma RNA was extracted, and a global screening of 752 microRNAs was analyzed using RT-qPCR. Three different c-miRNA profiles were defined according to the three doses. In 10K, 14 c-miRNAs were found to be differentially expressed between pre- and post-exercise, 13 upregulated and 1 downregulated. Regarding HM, 13 c-miRNAs were found to be differentially modulated, in all the cases upregulated. A total of 28 c-miRNAs were found to be differentially expressed in M, 21 overexpressed and 7 repressed after this race. We had also found 3 common c-miRNAs between 10K and M and 2 common c-miRNAs between 10K and HM. In silico analysis supported a close association between exercise dose c-miRNA profiles and cellular pathways linked to energy metabolism and cell cycle. In conclusion, we have observed that different exercise doses induced specific c-miRNA profiles. So, our results point to c-miRNAs as emerging exercise dose biomarkers and as one of regulatory mechanisms modulating the response to endurance exercise.

Age-related participation and performance trends of children and adolescents in ultramarathon running

ABSTRACT Participation and performance trends as well as the performance differences among sexes in ultra-endurance running have been well described in the adult population; however, less information on such trends existed in youth ultramarathoners. The aim of the present study was to investigate the age-related participation and performance trends of children and adolescent ultramarathoner runners. Data on runners, younger than 19 years of age, competing from 1960 to 2018 in distance-limited ultramarathons of 50 km, 100 km, 50 miles and 100 miles, were analysed. During this period, the number of ultramarathon participation increased, most notably among boys, most runners originated from Europe, and the 50- and 100-km race distances were the most popular. Overall, male runners were faster than female runners, except in the case of European and Oceanian origin, where girls were faster over the 50-km race. The fastest male runners originated from Africa and the fastest girls from Oceania, and the average running speed has largely decreased for both sexes over calendar years. In summary, this study was the first to report details on participation and performance trends in youth ultramarathoners competing in distance-limited ultramarathons.

Influence Of Performance Level Of Male Runners On Non-linear Dynamics Of Heart Rate Variability During a 10Km Race

ABSTRACT The present study examines the influence of a 10 km race of runners with different performance levels on time-domain measures and non-linear dynamics of HRV. Twenty-two male recreational to elite runners performed a self-paced 10 km race on asphalt with flat profile. The participants were divided into two performance groups based on their 10 km total time with a split at 40 min (fTT: fast total times, sTT: slow total times). During the race (Begin, Mid-Point, End), heart rate and RR-intervals were recorded continuously. Besides HRV time-domain measurements, fractal correlation properties using short-term scaling exponent alpha1 of Detrended Fluctuation Analysis (DFA) were calculated. Mean total time from fTT was significant faster compared to sTT (35:14 ± 03:15 min:sec vs. 46:34 ± 05:46 min:sec). While RMSSD and SDNN diminished strongly during the race with no differences between groups, we observed significant lower values in DFA-alpha1 at Begin for fTT. In comparison of Begin vs. Mid-Point as well as Begin vs. End a significant decrease could be determined in DFA-alpha1 for sTT. The earlier loss of correlation properties during Begin in fTT implies a fastened alteration of cardiac autonomic regulation in order to match an all-out performance attractor for maximal endurance performance.

Critical velocity estimates running velocity in a 10-km running race in recreational runners

Abstract The aim of this study was to compare the estimated running velocity in a critical velocity (CV) test with the real running velocity in a 10-km race. This is a cross-sectional study with a convenience sample of 34 runners, 20 males and 14 females (42,4 ± 11,0). The participants attended two days of testing and one day to participate in an official 10-km race. During the visits, the following tests were performed: i) 400-meter running track test and ii) 2000 meter running track test. They were randomly selected and held in official athletics track with at least 48 hours rest between them. The athletes were instructed to participate in the study properly recovered, fed and hydrated. The CV was calculated as the linear relation between distance and race time, corresponding to the slope of the linear regression line. Both tests occurred in similar climatic situations. We found good agreement between the velocities estimated through the CV test and the real running velocity of a 10-km race. Although there was a difference in velocities estimated by the CV test and the real 10-km race, the variation delta was low. Thus, these data indicate that the CV test seems to be a good tool for estimating the velocity of a 10-km race. The CV determined in the field with two fixed distances 400 and 2000 meter was valid to estimate the running velocity of a 10-km race.