Cardiac autonomic regulation following a 246-km mountain ultra-marathon: An observational study.

Physical exercise requires integrated autonomic and cardiovascular adjustments to maintain homeostasis. We aimed to observe acute posture-related changes in blood pressure, and apply a portable noninvasive monitor to measure the heart index for detecting arrhythmia among elite participants of a 246-km mountain ultra-marathon. Nine experienced ultra-marathoners (8 males and 1 female) participating in the Run Across Taiwan Ultra-marathon in 2018 were enrolled. The runners' Heart Spectrum Blood Pressure Monitor measurements were obtained in the standing and supine positions before and immediately after the race. Their high-sensitivity troponin T and N-terminal proB-type natriuretic peptide levels were analyzed 1 week before and immediately after the event. Heart rate was differed significantly in the immediate postrace assessment compared to the prerace assessment, in both the standing (P = .011; d = 1.19) and supine positions (P = .008; d = 1.35). Postural hypotension occurred in 4 (44.4%) individuals immediately postrace. In 3 out of 9 (33.3%) recruited finishers, the occurrence of premature ventricular complex signals in the standing position was detected; premature ventricular complex signal effect was observed in the supine position postrace in only 1 participant (11.1%). Premature ventricular complex signal was positively correlated with running speed (P = .037). Of the 6 individuals who completed the biochemical tests postrace, 2 (33.3%) had high-sensitivity troponin T and 6 (100%) had N-terminal proB-type natriuretic peptide values above the reference interval. A statistically significant increase was observed in both the high-sensitivity troponin T (P = .028; d = 1.97), and N-terminal proB-type natriuretic peptide (P = .028; d = 2.91) levels postrace compared to prerace. In conclusion, significant alterations in blood pressure and heart rate were observed in the standing position, and postexercise (postural) hypotension occurred among ultra-marathoners. The incidence of premature ventricular complexes was higher after the race than before.

Ultramarathon runners and support crew: The influence of pre-race sleep and training profiles on performance in a 217-km mountain race.

The present study evaluates the effects of pre-race sleep and training characteristics among ultra-athletes and support crew, and the influence of these factors on the athlete's performance in a 217-km ultramarathon. A total of 38 ultramarathon runners and 59 support crew members were assessed. The participants answered questionnaires about chronotype, sleep quality, sleepiness, basic demographics, and pre-race training. The clinical trial registration number is RBR-7j6d23v. The results showed that athletes and support crew had a morning-type chronotype and good sleep efficiency; most had poor-quality sleep. The athletes who finished the race had a higher sleep latency than non-finishers (p < 0.001). The quality of sleep may have impacted performance because the athletes with good sleep quality trained one day more per week than those without (p < 0.001), and training frequency was highly correlated with the race time (r = -0.59). These findings are novel, expand the data about sleep, training, and performance in an ultramarathon, and innovate by addressing the support crew.

Soft-Tissue Vibrations and Fatigue During Prolonged Running: Does an Individualized Midsole Hardness Play a Role?

Footwear has the potential to reduce soft-tissue vibrations (STV) but responses are highly subject-specific. Recent evidence shows that compressive garments minimizing STV have a beneficial effect on neuromuscular (NM) fatigue. The aim was to determine whether an individualized midsole hardness can minimize STV and NM fatigue during a half marathon. Twenty experienced runners were recruited for three visits: a familiarization session including the identification of midsole minimizing and maximizing STV amplitude (MIN and MAX, respectively), and two half marathon sessions at 95% of speed at the second ventilatory threshold. STV of the gastrocnemius medialis (GM) muscle, running kinetics, foot strike pattern, rating perceived exhaustion (RPE), and midsole liking were recorded every 3 km. NM fatigue was assessed on plantar flexors (PF) before (PRE) and after (POST) the half marathon. At POST, PF central and peripheral alterations and changes in contact time, step frequency, STV median frequency, and impact force frequency as well as foot strike pattern were found in both MIN and MAX. No significant differences in damping, STV main frequency, flight time, duty factor, and loading rate were observed between conditions whatever the time period. During the half marathon, STV amplitude of GM significantly increased over time for the MAX condition (+13.3%) only. Differences between MIN and MAX were identified for RPE and midsole liking. It could be hypothesized that, while significant, the effect of midsole hardness on STV is too low to substantially affect NM fatigue.

Outrunning the grim reaper: longevity of the first 200 sub-4 min mile male runners.

OBJECTIVES: To determine the impact of running a sub-4 min mile on longevity. It was hypothesised that there would be an increase in longevity for runners who successfully completed a sub-4 min mile compared with the general population. METHODS: As part of this retrospective cohort study, the Sub-4 Alphabetic Register was used to extract the first 200 athletes to run a sub-4 min mile. Each runner's date of birth, date of their first successful mile attempt, current age (if alive) or age at death was compared with the United Nations Life Tables to determine the difference in each runner's current age or age at death with their country of origin-specific life expectancy. RESULTS: Of the first 200 sub-4 min mile runners (100% male), 60 were dead (30%) and 140 were still alive. Sub-4 min mile runners lived an average of 4.7 years beyond their predicted life expectancy (95% CI 4.7 to 4.8). When accounting for the decade of completion (1950s, 1960s or 1970s), the longevity benefits were 9.2 years (n=22; 95% CI 8.3 to 10.1), 5.5 years (n=88; 95% CI 5.3 to 5.7) and 2.9 years (n=90; 95% CI 2.7 to 3.1), respectively. CONCLUSION: Sub-4 min mile runners have increased longevity compared with the general population, thereby challenging the notion that extreme endurance exercise may be detrimental to longevity.

Effect of Sugar- and Polyphenol-Rich, Diluted Cloudy Apple Juice on the Intestinal Barrier after Moderate Endurance Exercise and in Ultra-Marathon Runners.

BACKGROUND: Exercise and the consumption of sugars result in a dysfunction of the intestinal barrier (IB). Here, we determined the effect of sugar in a natural matrix on the intestinal barrier after moderate (A) and intensive endurance exercise (B). METHOD: The IB function was determined before (pre) and after running (post), and 120 and 180 min after consuming the drink by measuring serum endotoxin concentrations (lipopolysaccharides-LPS), IL-6, CD14, and i-FABP. In study A, nonspecifically trained participants (n = 24, males and females, age 26 ± 4) ran for one hour at 80% of their individual anaerobic threshold (IAT). After finishing, the runners consumed, in a crossover setup, either 500 mL of water, diluted cloudy apple juice (test drink), or an identical drink (placebo) without the fruit juice matrix (FJM). In study B, the participants (n = 30, males and females, age 50 ± 9) completed an ultra-marathon run, were divided into groups, and consumed one of the above-mentioned drinks. RESULTS: Study A: Exercise resulted in a significant increase in serum LPS, i-FABP, and IL-6, which decreased fast after finishing. No impact of the different drinks on LPS i-FABP, or IL-6 could be observed, but there was an impact on CD14. Study B: The ultra-marathon resulted in a strong increase in serum LPS, which decreased fast after finishing in the water and test drink groups, but not in the placebo group. CONCLUSIONS: The consumed drinks did not affect the kinetics of IB regeneration after moderate exercise, but impacted CD14 serum concentrations, indicating possible beneficial effects of the FJM on the immune system. After an ultra-marathon, IB function regenerates very fast. The intake of sugar (placebo) seems to have had a negative impact on IB regeneration, which was diminished by the presence of the FJM.

Acute effect of ultramarathon on systolic and diastolic cardiac function: Systematic review and meta-analysis.

BACKGROUND: Ultramarathon running poses physiological challenges, impacting cardiac function. This systematic review and meta-analysis explore the acute effects of single-stage ultramarathon running on cardiac function. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations were followed. Searches covered Medline, Embase, CINAHL, SPORTDiscus, Web of Science, Central Cochrane, and Scopus. Random effects meta-analyses assessed left ventricular (LV) and right ventricular (RV) variables, expressed as mean differences (MD) with 95% confidence intervals (CI). RESULTS: Among 6972 studies, 17 were included. Post-ultramarathon reductions were found in LV end-diastolic diameter (LVEDD) (-1.24; 95% CI = -1.77, -0.71 mm), LV end-diastolic volume (LVEDV) (-9.92; 95% CI = -15.25, -4.60 ml), LV stroke volume (LVSV) (-8.96 ml, 95% CI -13.20, -4.72 ml), LV ejection fraction (LVEF) (-3.71; 95% CI = -5.21, -2.22%), LV global longitudinal strain (LVGLS) (-1.48; 95% CI = -2.21, -0.76%), E/A (-0.30; 95% CI = -0.38, -0.22 cm/s), .E' (-1.35 cm/s, 95% CI -1.91, -0.79 cm/s), RV fractional area change (RVFAC) (-3.34, 95% CI = -5.84, -0.84%), tricuspid annular plane systolic excursion (TAPSE) (-0.12, 95% CI = -0.22, -0.02 cm), RV global longitudinal strain (RVGLS) (-1.73, 95% CI = -2.87, -0.59%), with increases in RV end-diastolic area (RVEDA) (1.89, 95% CI = 0.63, 3.14 cm2), RV Peak A' (1.32 cm/s, 95% CI 0.20, 2.44), and heart rate (18.24, 95% CI = 15.16, 21.32). No significant differences were observed in LV end-systolic diameter (LVESD), LV end-systolic volume (LVESV), RV end-diastolic diameter (RVEDD), RV Peak E', and RV Peak S'. CONCLUSIONS: Evidence suggests immediate impairment of systolic and diastolic cardiac function post-ultramarathon running.

Comparative electroencephalography analysis: Marathon runners during tapering versus sedentary controls reveals no significant differences.

INTRODUCTION: Previous studies described various adaptive neuroplastic brain changes associated with physical activity (PA). EEG studies focused mostly on effects during or shortly after short bouts of exercise. This is the first study to investigate the capability of EEG to display PA-induced long-lasting plasticity in runners compared to a sedentary control group. METHODS: Thirty trained runners and 30 age- and sex-matched sedentary controls (SC) were included as a subpopulation of the ReCaP (Running effects on Cognition and Plasticity) study. PA was measured with the International Physical Activity Questionnaire (IPAQ). Resting-state EEG of the runners was recorded in the tapering phase of the training for the Munich marathon 2017. Power spectrum analyses were conducted using standardized low-resolution electromagnetic tomography (sLORETA) and included the following frequency bands: delta: 1.5-6 Hz, theta: 6.5-8.0 Hz, alpha1: 8.5-10 Hz, alpha2: 10.5-12.0 Hz, beta1: 12.5-18.0 Hz, beta2: 18.5-21.0 Hz, beta3: 21.5-30.0 Hz, and total power (1.5-30 Hz). RESULTS: PA (IPAQ) and BMI differed significantly between the groups. The other included demographic parameters were comparable. Statistical nonparametric mapping showed no significant power differences in EEG between the groups. DISCUSSION: Heterogeneity in study protocols, especially in time intervals between exercise cessation and EEG recordings and juxtaposition of acute exercise-induced effects on EEG in previous studies, could be possible reasons for the differences in results. Future studies should record EEG at different time points after exercise cessation and in a broader spectrum of exercise intensities and forms to further explore the capability of EEG in displaying long-term exercise-induced plasticity.

Diffusion tensor imaging combined with chemical shift-encoded sequence to quantify the adaptive changes of calf muscles in amateur marathoners.

PURPOSE: Calf muscles play an important role in marathon race, and the incidence of injury is high in this process. This study prospectively quantified diffusion tensor metrics, muscle fat fraction (MFF) and cross-sectional area (CSA) of calf muscles induced by endurance exercise in amateur marathoners, and the potential mechanisms underlying the changes in these parameters were analyzed. METHOD: In this prospective study, 35 marathoners (27 males, 8 females; mean age (standard deviation, SD), 38.92 (4.83) years) and 26 controls (18 males, 8 females; mean age (SD), 38.35 (6.75) years) underwent magnetic resonance imaging (MRI) from September 2022 to March 2023. The diffusion tensor eigenvalues (λ1, λ2, λ3), radial diffusivity (RD), fractional anisotropy (FA), MFF and CSA of calf muscles were compared between marathoners and controls. A binary logistic regression model with gender correction was performed analyze the relationship between marathon exercise and DTI parameters, CSA and MFF of calf muscles. RESULTS: Interobserver agreement was good (κ = 0.71). The results of binary logistic regression model with gender correction showed that the regression coefficients of FA values in anterior group of calf (AC), soleus (SOL), medial gastrocnemius (MG) and lateral gastrocnemius (LG) were negative, and the odds ratios (OR) were 0.33, 0.45, 0.35, 0.05, respectively (P < 0.05). The OR of RD in SOL and λ2 in external group of calf (EC) were relatively higher, 3.74 and 3.26, respectively (P < 0.05). CSA was greater in SOL of marathoners, with an OR value of 1.00(P < 0.05). The MFF in AC and LG was lower in marathoners and OR of two indexes were -0.69 and -0.59, respectively (P < 0.05). CONCLUSIONS: Diffusion tensor imaging (DTI) combined with chemical shift-encoded sequence can noninvasively detect and quantify the adaptive changes of calf muscle morphology, microstructure and tissue composition induced by long-term running training in amateur marathoners.

The effect of marathon running on the lower extremity kinematics and muscle activities during walking and running tasks.

Patellofemoral pain syndrome (PFPS) is a common injury among runners, and it is thought that abnormal lower extremity biomechanics contribute to its development. However, the relationship between biomechanical changes after a marathon and PFPS injury remains limited. This study aims to investigate whether differences in knee and hip kinematics and lower extremity muscle activities exist in recreational runners before and after a marathon. Additionally, it aims to explore the relationship between these biomechanical changes and the development of PFPS injury. 12 recreational runners participated in the study. Kinematics and muscle activities of the lower extremity were recorded during walking (5 km/h) and running (10 km/h) tasks within 24 hours before and within 5 hours after a marathon. After the marathon, there was a significant decrease in peak knee flexion (walking: p = 0.006; running: p = 0.006) and an increase in peak hip internal rotation (walking: p = 0.026; running: p = 0.015) during the stance phase of both walking and running compared to before the marathon. The study demonstrates a decrease in knee flexion and an increase in hip internal rotation during the stance phase of gait tasks after completing a marathon, which may increase the risk of developing PFPS injury.

Exercise-induced Hypertension and Carotid Intima-media Thickness in Male Marathon Runners.

This study aimed to identify the relationship between exercise-induced hypertension and carotid artery intima-media thickness in long-distance runners. Sixty healthy male runners aged 40 to 60 years were assigned to the following three groups based on resting blood pressure and maximal systolic blood pressure during a maximal exercise test: normal blood pressure response, exercise-induced hypertension, and complex hypertension. An exaggerated systolic blood pressure response was defined as a maximal systolic blood pressure+≥+210 mmHg during the maximal exercise test, while carotid intima-media thickness was measured using B-mode ultrasonography. The carotid intima-media thickness mean values were the highest in the complex hypertension group (0.72±0.11 mm), followed by exercise-induced hypertension (0.62±0.12 mm) and normal blood pressure groups (0.55±0.13 mm), with a significant difference between the groups (p+<+0.002). In linear regression analysis, the mean intima-media thickness was independently associated with age (p=0.015) and maximal systolic blood pressure (p=0.046) but not with resting systolic blood pressure. These results suggest that exercise-induced hypertension is associated with carotid intima-media thickness, a surrogate marker of cardiovascular disease, in long-distance runners. Therefore, evaluating the blood pressure response during exercise is important for the early detection of potential cardiovascular disease risks in long-distance runners.

Changes in Skeletal Muscle Troponin T and Vitamin D Binding Protein (DBP) Concentrations in the Blood of Male Amateur Athletes Participating in a Marathon and 100 km Adventure Race.

This study assessed changes in creatine kinase (CK) activity and skeletal muscle troponin T (sTnT) concentrations in the blood, to estimate the degree of muscle degradation after exercise. In addition, the concentration of vitamin D binding protein (DBP) in the blood was assessed. DBP concentrations were measured in blood as a marker for plasma load by monomeric actin. The study included marathon (MR) participants and 100 km adventure race (AR) participants, who were examined before and after the race. There was a significant (16-fold) increase in CK activity among AR participants, and a significant increase in sTnT concentration-127% in the MR group and 113% in the AR group, while there was a statistically significant decrease in DBP concentration by 14% in the AR group. In addition, it was observed that the initial concentration of DBP in both groups was in a normal range, but was lower than the average population, and the DBP concentration in the AR group was lower than in the MR group. It was concluded that exhausting physical effort such as a marathon or adventure races causes muscle damage with a far stronger influence on sarcoplasm than on filaments. The short-term and slight reduction in the concentration of DBP in blood after such efforts may be due to the appearance of monomeric actin in plasma.

How to end up on the podium after running a 6-days-run with type 1 diabetes mellitus - A case study and literature review.

BACKGROUND: An increasing number of people living with type 1 diabetes mellitus (T1DM) are pushing their physical limits to compete at the sport's highest level. Muscle, liver, and glycogen metabolism can be normal in athletes with diabetes with good glucose management, and modifications to insulin dose and nutrition can facilitate exercise performance. CASE PRESENTATION: We report on a 66-year-old runner with insulin-dependent T1DM. He has run over 90 marathons and ultra-marathons. Thanks to an insulin pump and continuous glucose monitoring, he has completed forty-eight 24-hour runs with an average performance of 133.8 km. Over the years, the runner increased his monthly running volume significantly and decreased his glycated Hemoglobin type A1C (hba1c) levels. Meanwhile, a significant association between monthly running kilometers and hba1c levels could be shown. At the age of 66 years, he finished his sixth 6-day-run in third place overall by covering a total distance of 467.424 km. CONCLUSIONS: These findings show that it is possible to participate in ultra-endurance events while suffering from T1DM without glucose derailing. With a good understanding of the disease and its impact on an individual's body, we can curtail the preparation and execution phases of ultra-endurance events to allow athletes to compete with minimal risk.

Effect of ultramarathon running on iron metabolism.

BACKGROUND: Iron is a vital trace element for energy production and oxygen transportation; importantly, it is essential to athletic performance. Maintaining iron balance is tightly controlled at systemic and cellular levels. This study aimed to determine serum iron tests, hepcidin levels, and cellular iron import and export activities in peripheral blood mononuclear cells (PBMCs) in ultramarathon runners to elucidate the association of systemic inflammation response and iron metabolism. METHODS: Sixteen amateur runners were enrolled. Blood samples were taken 1 week before, immediately, and 24 h after the run. Plasma hepcidin levels were measured by enzyme-linked immunosorbent assay. The expression levels of divalent metal iron transporter 1 (DMT1), ZRT/IRT-like protein 14 (ZIP14), transferrin receptor 1 (TfR1), and ferroportin (FPN) in PBMCs were measured using real-time quantitative reverse transcription-polymerase chain reaction. RESULTS: Serum iron concentrations and transferrin saturation significantly decreased immediately after the race and dramatically recovered 24 h post-race. Serum ferritin levels had a statistically significant rise immediately after the race and remained high 24 h after the completion of the race. Ultramarathons were associated with increased plasma interleukin-6 concentrations corresponding to the state of severe systemic inflammation and therefore boosted plasma hepcidin levels. The expression levels of DMT1 and FPN mRNA were markedly decreased immediately and 24 h after the race. The ZIP14 and TfR1 mRNA expression in PBMCs significantly decreased immediately after the race and returned to the baseline level at 24 h post-race. Positive significant correlations were observed between plasma hepcidin and ferritin levels. CONCLUSION: Iron homeostasis and systemic inflammatory response are closely interconnected. Cellular iron import and export mRNA activities in PBMCs were acutely inhibited during an ultramarathon.

A Narrative Analysis of the Progression in the Top 100 Marathon, Half-Marathon, and 10-km Road Race Times from 2001 to 2019.

PURPOSE: This study aimed to characterize and describe finishing time trends of the fastest 100 performers in the men's and women's marathon, half-marathon, and road 10-km each year from 2001 to 2019 and assess the underlying basis for recent performance improvements. METHODS: The top 100 performers for each sex, event, and year were partitioned into four arbitrary ranking groups: 1-10, 11-25, 26-50, and 51-100. The percent improvement in mean performance time for each year beyond 2001 was calculated for each ranking group, event, and sex. Multiple linear regression was also used to determine improvement trend for each ranking group, both sexes, and all events for each 3-yr period between Olympic years. RESULTS: In total, 11,400 performances in the marathon, half-marathon, and 10-km road races from 2001 to 2019 were analyzed. The 3-yr period preceding the original date of the Tokyo Olympics (2017-2019) accounted for 44% and 35% of the overall improvement in marathon time from 2001 to 2019 for women and men, respectively. The years 2017-2019 featured the largest average improvement of any 3-yr period and was the only period where nearly every ranking group in every event for both sexes improved. CONCLUSIONS: The results suggest that recent world record performances are a result of overall circumstances affecting road racing (e.g., shoe technology) rather than the outstanding physiology of individual top runners, per se.

Comparing Acute, High Dietary Protein and Carbohydrate Intake on Transcriptional Biomarkers, Fuel Utilisation and Exercise Performance in Trained Male Runners.

Manipulating dietary macronutrient intake may modulate adaptive responses to exercise, and improve endurance performance. However, there is controversy as to the impact of short-term dietary modification on athletic performance. In a parallel-groups, repeated measures study, 16 trained endurance runners (maximal oxygen uptake (V˙O2max): 64.2 ± 5.6 mL·kg-1·min-1) were randomly assigned to, and provided with, either a high-protein, reduced-carbohydrate (PRO) or a high-carbohydrate (CHO) isocaloric-matched diet. Participants maintained their training load over 21-consecutive days with dietary intake consisting of 7-days habitual intake (T1), 7-days intervention diet (T2) and 7-days return to habitual intake (T3). Following each 7-day dietary period (T1-T3), a micro-muscle biopsy was taken for assessment of gene expression, before participants underwent laboratory assessment of a 10 km treadmill run at 75% V˙O2max, followed by a 95% V˙O2max time to exhaustion (TTE) trial. The PRO diet resulted in a modest change (1.37-fold increase, p = 0.016) in AMPK expression, coupled with a significant increase in fat oxidation (0.29 ± 0.05 to 0.59 ± 0.05 g·min-1, p < 0.0001). However, a significant reduction of 23.3% (p = 0.0003) in TTE post intervention was observed; this reverted back to pre levels following a return to the habitual diet. In the CHO group, whilst no change in sub-maximal fuel utilisation occurred at T2, a significant 6.5% increase in TTE performance (p = 0.05), and a modest, but significant, increase in AMPK (p = 0.042) and PPAR (p = 0.029) mRNA expression compared to T1 were observed; with AMPK (p = 0.011) and PPAR (p = 0.044) remaining significantly elevated at T3. In conclusion, a 7-day isocaloric high protein diet significantly compromised high intensity exercise performance in trained runners with no real benefit on gene markers of training adaptation. A significant increase in fat oxidation during submaximal exercise was observed post PRO intervention, but this returned to pre levels once the habitual diet was re-introduced, suggesting that the response was driven via fuel availability rather than cellular adaptation. A short-term high protein, low carbohydrate diet in combination with endurance training is not preferential for endurance running performance.

Effect of Daily Oral Lactobacillus plantarum PS128 on Exercise Capacity Recovery after a Half-Marathon.

A half-marathon (HM) is a vigorous high-intensity exercise, which could induce lower extremity musculoskeletal injury risks for recreational runners. They usually consume nonsteroidal anti-inflammatory drugs (NSAIDs) in order to shorten their return to play but ignore the side effects, such as peptic ulcers and renal and vascular disorders. Lactobacillus plantarum PS128 (PS128) could improve inflammation and oxidative stress by modulating the gut microbiota, thus potentially improving muscle damage and recovery. However, few studies have addressed the PS128 exercise capacity recovery 96 h after HM. Thus, this study aimed to investigate the effect of PS128 on exercise capacity and physiological adaptation after HM. A double-blind, randomized, placebo-controlled, counterbalanced, crossover trial was used for the experiment. HM was conducted at the beginning and end of the 4-week nutritional supplement administration. Eight recreational runners took two capsules (3 × 1010 CFU/capsule) of PS128 each morning and evening before meals for 4 weeks as the PS128 treatment (LT), or they took two capsules of placebo for 4 weeks as the placebo treatment (PT). In both treatments, an exercise capacity test (lower extremity muscle strength, anaerobic power, lower extremity explosive force, and aerobic capacity) and blood test (muscle fatigue, muscle damage, oxidative stress, and renal injury) were performed before the administration of the nutritional supplement (baseline), 48 h before HM (pre), and 0 h (0 h post), 3 h (3 h post), 24 h (24 h post), 48 h (48 h post), 72 h (72 h post), and 96 h (96 h post) after HM. There was no significant difference in the total duration of HM between PT and LT, but PT was found to be significantly higher than LT at Stage 4 (15,751-21,000 m) of HM (3394 ± 727 s vs. 2778 ± 551 s, p = 0.02). The lower extremity muscle strength measured using an isokinetic dynamometer in PT was significantly lower than that in LT at 72 h after HM. The lower extremity explosive force from the countermovement jump (CMJ) in PT was significantly decreased compared to 24 h prior. There was no significant difference between anaerobic power and aerobic capacity between the two treatments after HM. After HM, LT had lower muscle damage indices, such as myoglobin (3 h post-PT vs. -LT: 190.6 ± 118 ng/mL vs. 91.7 ± 68.6 ng/mL, p < 0.0001) and creatine phosphokinase (24 h post-PT vs. -LT: 875.8 ± 572.3 IU/L vs. 401 ± 295.7 IU/L, p < 0.0001). Blood urea nitrogen recovered in 24 h (24 h pre- vs. post-LT, p > 0.05) and higher superoxide dismutase was found in LT (96 h post-PT vs. -LT: 0.267 ± 0.088 U/mL vs. 0.462 ± 0.122 U/mL, p < 0.0001). In conclusion, PS128 supplementation was associated with an improvement in muscle damage, renal damage, and oxidative stress caused by HM through microbiota modulation and related metabolites but not in exercise capacity.

Supplement intake in half-marathon, (ultra-)marathon and 10-km runners - results from the NURMI study (Step 2).

The primary nutritional challenge facing endurance runners is meeting the nutrient requirements necessary to optimize the performance and recovery of prolonged training sessions. Supplement intake is a commonly used strategy by elite and recreational distance runners to meet nutritional recommendations. This study was conducted to investigate the patterns of supplement intake among different groups of distance runners and the potential association between supplement intake and sex, age, running and racing experiences.In a cross-sectional design, from a total of 317 runners participating in this survey, 119 distance runners were involved in the final sample after data clearance, assigned into three groups of 10-km runners (n = 24), half-marathoners (n = 44), and (ultra-)marathoners (n = 51). Personal characteristics, training and racing experiences, as well as patterns of supplement intake, including type, frequency, and dosage, were evaluated by questionnaire. Food Frequency Questionnaire was implemented to assess macronutrient intake. ANOVA and logistic regression were used for statistical analysis.While 50 % of total distance runners reported consuming supplements regularly, no differences between distance groups in consumption of carbohydrate/protein, mineral, or vitamin supplements were observed (p > 0.05). In addition, age, sex, running and racing experience showed no significant association with supplement intake (p > 0.05). Vitamin supplements had the highest intake rate in runners by 43 % compared to minerals (34 %) and carbohydrate/protein supplements (19 %).The present findings provide a window into the targeted approaches of long-distance runners as well as their coaches and sport nutrition specialists when applying and suggesting sustainable nutritional strategies for training and competition.Trial registration: ISRCTN73074080. Retrospectively registered 12th June 2015.

Sex differences in cardiovascular adaptations in recreational marathon runners.

INTRODUCTION: There are well-established sex differences in central hemodynamic and cardiac adaptations to endurance exercise; however, controversial evidence suggests that excessive endurance exercise may be related to detrimental cardiovascular adaptations in marathoners. PURPOSE: To examine left ventricle (LV) structure, LV function, 24-h central hemodynamics and ventricular-vascular coupling in male and female marathoners and recreationally active adults. METHODS: 52 marathoners (41 ± 5 years, n = 28 female, completed 6 ± 1 marathons/3 years) and 49 recreationally active controls (42 ± 5 years, n = 25 female) participated in the study. Three-Dimensional Echocardiography (3DE) was used to measure LV mass index and LV longitudinal (LS) circumferential (CS), area (AS), and radial strain (RS). An ambulatory blood pressure (BP) cuff was used to measure 24-h central hemodynamics (BP, pulse wave velocity, PWV, wave reflection index, RIx). Hemodynamic and 3DE measures were combined to derive the ratio of arterial elastance (Ea) to ventricular elastance (Elv) as a global measure of ventricular-vascular coupling. RESULTS: There were no sex or group differences in LS, CS, AS, and RS (p > 0.05). Females marathoners had similar aortic BP (116 ± 9 vs. 113 ± 1 mmHg), and PWV (5.9 ± 0.5 vs. 5.9 ± 1.1 m/s) compared to female controls but lower aSBP (116 ± 9 vs. 131 ± 10 mmHg) and PWV (5.9 ± 0.5 vs. 6.2 ± 0.5 m/s) compared to male marathoners (p < 0.05). Female marathoners had lower Ea/Elv than female controls (0.67 ± 0.20 vs. 0.93 ± 0.36) and male marathoners (0.67 ± 0.20 vs. 0.85 ± 0.42, p < 0.05). CONCLUSIONS: Women that have completed multiple marathons do not have reduced LV function or increased aortic stiffness and may have better ventricular-vascular coupling compared to male marathoners and their female untrained counterparts.

Blood serum denaturation profile examined by differential scanning calorimetry reflects the effort put into ultramarathon by amateur long-distance runners.

The impact of participation in the ultramarathon on the health and mental and physical condition is very complex. Undoubtedly, exercise brings many benefits but also involves health risks. Especially such an extreme effort as the one associated with finishing the ultramarathon run, can be dangerous to the health of the runner. With the variety of possible biomarkers of excessive fatigue that threaten health and life, a question arises which of them are the best and which should be considered in amateur long-distance runners showing particularly high individual variability. In this study differential scanning calorimetry (DSC) has been applied to show the overall effect of the 12-h run on blood sera of participants. Serum samples were obtained from the blood of ten male amateur long-distance runners, collected before and immediately after the run. Distinct changes in the shape of DSC curves have been observed for serum after finishing the run relative to pre-race serum. Statistically significant differences between stages "before" and "after" ultramarathon running have been found for parameters of the endothermic transition associated with denaturation of serum proteins. An increase in the temperature (from 70.9 ± 0.9 to 75.8 ± 2.9 °C) and excess heat capacity (from 0.859 ± 0.201 to 1.102 ± 0.226 Jg-1 °C-1) at peak maximum, the enthalpy of serum denaturation (from 18.55 ± 6.52 to 22.08 ± 5.61 Jg-1) and the first moment of the thermal transition with respect to the temperature (from the value of 67.0 ± 2.1 to 72.6 ± 2.1 °C) has been observed. These results show a clear impact of running an ultramarathon on the participant's blood serum.

Fractal correlation properties of heart rate variability as a biomarker of endurance exercise fatigue in ultramarathon runners.

Although heart rate variability (HRV) indexes have been helpful for monitoring the fatigued state while resting, little data indicate that there is comparable potential during exercise. Since an index of HRV based on fractal correlation properties, alpha 1 of detrended fluctuation analysis (DFA a1) displays overall organismic demands, alteration during exertion may provide insight into physiologic changes accompanying fatigue. Two weeks after collecting baseline demographic and gas exchange data, 11 experienced ultramarathon runners were divided into two groups. Seven runners performed a simulated ultramarathon for 6 h (Fatigue group, FG) and four runners performed daily activity over a similar period (Control group, CG). Before (Pre) and after (Post) the ultramarathon or daily activity, DFA a1, heart rate (HR), running economy (RE) and countermovement jumps (CMJ) were measured while running on a treadmill at 3 m/s. In Pre versus Post comparisons, data showed a decline with large effect size in DFA a1 post intervention only for FG (Pre: 0.71, Post: 0.32; d = 1.34), with minor differences and small effect sizes in HR (d = 0.02) and RE (d = 0.21). CG showed only minor differences with small effect sizes in DFA a1 (d = 0.19), HR (d = 0.15), and RE (d = 0.31). CMJ vertical peak force showed fatigue-induced decreases with large effect size in FG (d = 0.82) compared to CG (d = 0.02). At the completion of an ultramarathon, DFA a1 decreased with large effect size while running at low intensity compared to pre-race values. DFA a1 may offer an opportunity for real-time tracking of physiologic status in terms of monitoring for fatigue and possibly as an early warning signal of systemic perturbation.