Effect of ultra-endurance exercise on left ventricular performance and plasma cytokines in healthy trained men

A new perspective on cardiovascular function and dysfunction during endurance exercise: identifying the primary cause of cardiovascular risk

Exercise mechanical efficiency typically falls within the range of approximately 20 to 25%. This means that a great part of the metabolic energy converted to generate movement is released as heat. Therefore, the rise in core temperature during endurance exercise in humans is proportional to generated work. Cutaneous vasodilation occurs when the core temperature threshold is reached. The rise in heart rate in response to thermal stress is a cardiovascular response that increases cardiac output and skin blood flow. The cardiovascular response during endurance exercise is a complex phenomenon potentially influenced by the involvement of nitric oxide in active thermoregulatory vasodilation. Excessive exercise can create high oxidative stress by disrupting the balance between free radicals' production and scavenging, resulting in impaired cardiovascular function. The above considerations are related to the severity and duration of endurance exercise. The first focus of this narrative review is to provide an updated understanding of cardiovascular function during endurance exercise. We aim to explore the potential role of oxidative stress in causing cardiovascular dysfunction during endurance exercise from a fresh perspective. Additionally, we aim to identify the primary factors contributing to cardiovascular risk during strenuous prolonged exercise by highlighting recent progress in this area, which may shed light on previously unexplained physiological responses. To ascertain the effect of endurance exercise on cardiovascular function and dysfunction, a narrative review of the literature was undertaken using PubMed, ScienceDirect, Medline, Google Scholar, and Scopus. The review highlighted that high oxidative stress (due to high levels of catecholamines, shear stress, immune system activation, and renal dysfunction) leads to a rise in platelet aggregation during endurance exercise. Importantly, we clearly revealed for the first time that endothelial damage, vasoconstriction, and blood coagulation (inducing thrombosis) are potentially the primary factors of cardiovascular dysfunction and myocardial infarction during and/or following endurance exercise.

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.

Beyond muscles: Investigating immunoregulatory myokines in acute resistance exercise - A systematic review and meta-analysis

Myokines, released from the muscle, enable communication between the working muscles and other tissues. Their release during physical exercise is assumed to depend on immune-hormonal-metabolic interactions concerning mode (endurance or resistance exercise), duration, and intensity. This meta-analysis aims to examine the acute changes of circulating myokines inducing immunoregulatory effects caused by a bout of resistance exercise and to consider potential moderators of the results. Based on this selection strategy, a systematic literature search was conducted for resistance exercise intervention studies measuring interleukin (IL-) 6, IL-10, IL-1ra, tumor necrosis factor (TNF-) α, IL-15, IL-7, transforming growth factor (TGF-) β1, and fractalkines (FKN) before and immediately after resistance exercise in healthy individuals. Random-effects meta-analysis was performed for each myokine. We identified a moderate positive effect of resistance exercise for IL-6 and IL-1ra. Regarding IL-15 and TNF-α, small to moderate effects were found. For IL-10, no significant effect was observed. Due to no data, meta-analyses for IL-7, TGF-β1, and FKN could not be performed. No moderators (training status, type of exercise, risk of bias, age, sex, time of day, exercise volume, exercise intensity, exercise dose) of the results were detected for all tested myokines. Taken together, this systematic review and meta-analysis showed immediate positive effects of an acute resistance exercise session on IL-6, IL-1ra, TNF-α, and IL-15 levels.

Insult of Ultraendurance Events on Blood Pressure: A Systematic Review and Meta-Analysis

The rise of ultraendurance sports in the past two decades warrants evaluation of the impact on the heart and vessels of a growing number of athletes participating. Blood pressure is a simple, inexpensive method to evaluate one dimension of an athlete's cardiovascular health. No systematic review or meta-analysis to date has chronicled and delineated the effects of ultraendurance races, such as ultramarathons, marathons, half-marathons, and Ironman triathlon events, specifically on heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP) measurements in supine and standing positions before and after the event. This meta-analysis reviews the effects of ultraendurance events on positional and calculated hemodynamic values. Data were extracted from 38 studies and analyzed using a random effects model with a total of 1,645 total blood pressure measurements. Of these, 326 values were obtained from a standing position, and 1,319 blood pressures were taken supine. Pre-race and post-race measurements were evaluated for clinical significance using established standards of hypotension and orthostasis. HR and calculated BP features, such as PP and MAP, were evaluated. Across all included studies, the mean supine post-race HR increased by 21±8 beats per minute (bpm) compared to pre-race values. The mean standing post-race HR increased by 23±14 bpm when compared with pre-race HR. Overall, there was a mean SBP decrease of 19±9 mmHg and a DBP decrease of 9±5 mmHg post-race versus pre-race values. MAP variations reflected SBP and DBP changes. The mean supine and standing pre-race blood pressures across studies were systolic (126±7; 124±14) and diastolic (76±6; 75±12), suggesting that some athletes may enter races with existing hypertension. The post-race increase in the mean HR and decline in mean blood pressure across examined studies suggest that during long-term events, ultramarathon athletes perform with relatively asymptomatic hypotension.

Correlation Between Inflammatory and Epigenetic Marks With Aerobic Performance in 10-km Runners

Purpose: Our goals were to evaluate the effect of a 10-km running trial on inflammatory and epigenetic markers of 10-km runners and correlate the biochemical findings with anthropometric variables and performance. Methods: Twenty trained 10-km runners and seven sedentary male volunteers were recruited. Venous blood samples were collected at different times: under resting conditions, before the 10 Km race, and immediately after the finish. Inflammatory markers (IL-6, IL-10, and IL-β) and cortisol levels were evaluated in plasma, while DNA methyltransferases (DNMT1 and DNMT3b) contents were measured in peripheral blood mononuclear cells (PBMCs). Results: Higher levels of plasma IL-6 levels were observed in 10-km runners compared to the sedentary group. After the trial, the runners had a significant increase on IL-6, IL-10, and cortisol plasma levels compared to baseline. Conclusion: Our findings suggest that inflammatory profile, but not DNMT content, influences aerobic performance in 10-km runners.

Acute effects of long-distance races on heart rate variability and arterial stiffness: A systematic review and meta-analysis

This study systematically reviewed and quantified the effects of running a long-distance race (LDR) on heart rate variability (HRV) and arterial stiffness (AS). All types of races of a distance equal to or greater than a marathon (≥42.2 km) were included. A total of 2,220 articles were identified, 52 were included in the qualitative analysis, and 48 were meta-analysed. The standardised mean difference pre- and post-race of various time-domain and frequency-domain indices of HRV, mean arterial blood pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP) and carotid-femoral pulse wave velocity (cfPWV) was calculated. Regarding HRV, there was a significant decrease in most of the variables considered as markers of parasympathetic activity, indicating a shift of autonomic balance towards a reduced vagal tone. Regarding vascular variables, there was a significant drop in blood pressure and reduced AS. In conclusion, running an LDR seems to have a considerable acute effect on the autonomic nervous system, haemodynamics, and vascular properties. The observed effects could be categorised within the expected acute responses to long-lasting, strenuous exercise.

Postexercise Inflammasome Activation and IL-1β Production Mitigated by Flavonoid Supplementation in Cyclists

Inflammasomes are multiprotein signaling platforms of the innate immune system that detect markers of physiological stress and promote the maturation of caspase-1 and interleukin 1 beta (IL-1β), IL-18, and gasdermin D. This randomized, cross-over trial investigated the influence of 2-week mixed flavonoid (FLAV) versus placebo (PL) supplementation on inflammasome activation and IL-1β and IL-18 production after 75-km cycling in 22 cyclists (42 ± 1.7 years). Blood samples were collected before and after the 2-week supplementation, and then 0 hr, 1.5 hr, and 21 hr postexercise (176 ± 5.4 min, 73.4 ± 2.0 %VO2max). The supplement (678 mg FLAVs) included quercetin, green tea catechins, and bilberry anthocyanins. The pattern of change in the plasma levels of the inflammasome adaptor oligomer ASC (apoptosis-associated speck-like protein containing caspase recruitment domain) was different between the FLAV and PL trials, with the FLAV ASC levels 52% lower (Cohen's d = 1.06) than PL immediately following 75-km cycling (interaction effect, p = .012). The plasma IL-1β levels in FLAV were significantly lower than PL (23-42%; Cohen's d = 0.293-0.644) throughout 21 hr of recovery (interaction effect, p = .004). The change in plasma gasdermin D levels were lower immediately postexercise in FLAV versus PL (15% contrast, p = .023; Cohen's d = 0.450). The patterns of change in plasma IL-18 and IL-37 did not differ between the FLAV and PL trials (interaction effects, p = .388, .716, respectively). These data indicate that 2-week FLAV ingestion mitigated inflammasome activation, with a corresponding decrease in IL-1β release in cyclists after a 75-km cycling time trial. The data from this study support the strategy of ingesting high amounts of FLAV to mitigate postexercise inflammation.

Diastolic Function and Biomarkers of Long-Distance Walking Participants

BACKGROUND

The effects of long-distance walking on the cardiovascular system have been little studied.

OBJECTIVES

The general objective of this study was to verify these effects on the behavior of diastolic function and the cardiac biomarkers CK-MB (mass), troponin T, and NT-proBNP, in amateur athletes.

METHOD

This longitudinal study, conducted in 2015, evaluated participants during the following 5 stages: E0 (baseline) before starting the trajectory and the others, E1, E2, E3, and E4, at the end of each day, totaling 244.7 km. At all stages, the biomarkers NT-proBNP, CK-MB (mass), and troponin T were measured. Echocardiogram was performed to analyze the E, A and E' waves. P < 0.05 was adopted as significant.

RESULTS

The study evaluated 25 participants, with an average age of 46 ± 10.5 years and body mass index of 20.2 ± 2.3 kg/m2. Increased values were found for NT-proBNP from E0 to E1, E2, E3, and E4 (p < 0.001), CK-MB (mass) from E0 to E2 (p < 0.001), and E' wave from E0 to E1, E2, E3, and E4 (p < 0.001). Positive correlations were identified between the following: CK-MB (mass) and troponin T (E1: r = 0.524, p = 0.010; E4: r = 0.413, p = 0.044); CK-MB (mass) and NT-proBNP (E4: r = 0.539, p = 0.006); and E/A and E' (E0: r = 0.603, p < 0.001; E1: r = 0.639, p < 0.001; E4: r = 0.593, p = 0.002). A negative correlation was found between CK-MB (mass) and E/A (E1: r = -0.428, p = 0.041).

CONCLUSION

The effects of intense, prolonged, and interspersed physical activity were verified based on significant variations in the behavior of CK-MB (mass), NT-proBNP, and the E' wave. Notwithstanding the alterations found, there were no criteria suggestive of myocardial damage.

Association of the TNF-α -308G/A polymorphism with lipid profile changes in response to aerobic training program

Promoter polymorphism of the tumor necrosis factor-α (TNF-α) gene is associated with obesity-related traits, although the role of its potential modifying effect on changes in obesity-related parameters achieved through a training program is still unknown. The aim of the present study was to examine whether the TNF-α-308G/A polymorphism (rs1800629) influences the effects of a training program. Accordingly, we studied the alleles and genotypes distribution in a group of 168 Polish Caucasian women measured for selected body mass and composition, as well as biochemical parameters before and after the realization of a 12-week aerobic training program. Our results showed that TNF-α genotypes can modulate training-induced biochemical parameter changes such as lipid profile. We demonstrated that carriers of the GG genotype are associated with decreases in post-training high-density lipoprotein cholesterol (HDL-C) levels (p<0.001). Additionally, we revealed that participants with the GG genotype had a higher low-density lipoprotein cholesterol (LDL-C) level (p=0.046) during the entire study period. It could be concluded that harboring the GG genotype of rs1800629 may be considered to be a disadvantageous factor in the context of training-induced effects on lipid profile changes in young female participants.

Interleukin-10 responses from acute exercise in healthy subjects: A systematic review

PURPOSE

Interleukin 10 (IL-10) is a cytokine that plays a critical role with potent anti-inflammatory properties when produced during exercise, limiting host immune response to pathogens and preventing tissue damage. The purpose of this systematic review was to assess the response of IL-10 after acute exercise session in healthy adults.

METHODS

Databases of Ovid Medline (1978-2016), CINAHL (1998-2016), EMBASE (2003-2016), SportDiscus (1990-2016), and Web of Science library (1990-2016) were carefully screened. Clinical trials comparing exercise types in healthy individuals were included for pooled analysis. The trials of exercise were methodologically appraised by PEDro Scale.

RESULTS

Twelve randomized controlled and crossover trials containing 176 individuals were identified for inclusion. The Kruskal-Wallis test showed no significant differences between type of exercise and the corresponding values in IL-10 [X2(4) = 2.878; p = 0.449]. The duration of exercise was significantly correlated with increase in IL-10 changes (Pearson's r = 1.00, 95%CI: 0.015-0.042, p < 0.0001) indicating that 48% of the variation in IL-10 levels can be explained by the duration of the exercise performed. In addition, despite a linear increase, we did not find a significant correlation with the intensity of exercise and IL-10 changes (Pearson's r = 0.218, 95%CI: -0.554-0.042, p < 0.035).

CONCLUSION

Overall, the duration of the exercise is the single most important factor determining the magnitude of the exercise-induced increase of plasma IL-10.

Acute long-distance trail running increases serum IL-6, IL-15, and Hsp72 levels

Interleukin-6 (IL-6), IL-15, and heat shock protein 72 (Hsp72) are molecules that have significant metabolic effects on glucose and fat metabolism and a cell's stress response. The aim of this study is to determine serum levels of these molecules in runners after a long-distance trail run. Serum IL-15 levels after such endurance events have not been investigated yet. Blood samples were collected from 37 athletes (11 female, 26 male) before and after a 35-km trail run, with a total climb of 940 m. Serum was obtained from the samples, and IL-6, IL-15, and Hsp72 levels were measured from using the sandwich ELISA method. The athletes completed the race in 308.3 ± 37.4 min on average. After the race, the mean serum IL-6, IL-15, and Hsp72 concentrations increased 13.2-fold, 2.22-fold, and 1.6-fold, respectively (p < 0.001, p < 0.001, and p = 0.039, respectively). This is the first study to demonstrate the increase in serum IL-15 levels following an acute endurance exercise. In addition to IL-15, we report that IL-6 and soluble Hsp72 levels also increased significantly following a 35-km trail run. Since these molecules are involved in regulating glucose and fat metabolism, significant increases of IL-6, IL-15, and soluble Hsp72 may have health benefits that may be associated with long-distance trail runs, which are becoming more popular worldwide.

Physiology and Pathophysiology in Ultra-Marathon Running

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

DAILY HEMATOLOGIC ASSESSMENT DURING A 230-KM MULTISTAGE ULTRAMARATHON

ABSTRACT Introduction: The popularity of ultra-endurance events is increasing worldwide. However, information about hematological parameters during repeated bouts of long-duration running, such as stages during a multi-stage ultramarathon (MSUM) is scarce. Objective: The purpose of the study was to monitor daily hematologic assessment in a 230-km multistage ultramarathon (MSUM) in hot environmental conditions. Methods: Eleven male and three female (n = 14) ultra-endurance runners entered this MSUM, which was conducted over five stages, covering a total distance of 230 km in hot ambient conditions. Peripheral blood samples were collected before and after each stage to determine leukocyte and erythrocytes parameters. Results: Multilevel modelling considering all measurement points showed an increase for whole blood leukocyte and granulocyte counts at five stages of the MSUM and for monocytes until Stage 3 of the race. For erythrocyte parameters, decreases across stages were observed in hemoglobin concentration and hematocrit responses when computing/considering all measurement points. Conclusions: The results indicate that MSUM in a hot environment leads to a greater impact on leukocyte population responses and platelet variation in the initial stages of the race. We suggest that athletes may have a decrease in immune function in the early stages of the MSUM, probably with some transient risk of infectious. Nevertheless, a physiological adaptation to physical exertion and heat mitigates these changes in the subsequent stages of MSUM. Level of Evidence III; Case-control study.

[Not Available]

Zusammenfassung. Wir stellen die wichtigsten Erkenntnisse zu Organschädigungen durch einen Ultramarathon zusammen. Nach einem Ultramarathon können kardiale Biomarker wie CK, CK-MB, kardiales Troponin I (cTnI) und N-terminales pro-Brain Natriuretic Peptide (NT-pro BNP) erhöht sein. Bis 80 % und mehr der Finisher klagen über Verdauungsprobleme, die einer der Hauptgründe sind, einen Ultramarathon nicht zu finishen. Bis zu 90 % der Läufer, die einen Ultramarathon aufgeben, klagen über Übelkeit. Nach einem Ultramarathon steigen die Leberwerte oft an, schwerwiegende Konsequenzen bleiben meist aus. Risikofaktoren für eine Einschränkung der Nierenfunktion sind eine ausgeprägte Muskelschädigung mit Rhabdomyolyse, Dehydratation, Hypotonie, Hyperurikämie, Hyponatriämie, geringe Wettkampferfahrung sowie die Einnahme von NSARs. Ultraläufer leiden nach einem Ultramarathon oft an Infekten der oberen Atemwege.

Serum but not exhaled breath condensate periostin level is increased in competitive athletes

INTRODUCTION

Periostin is a matricellular protein expressed by many tissues. Its release may be enhanced, among others, through mechanical stimulation of muscles and bones as well as by cytokines of allergic inflammation.

OBJECTIVES

Our aim was to assess periostin levels in serum and exhaled breath condensate (EBC) of professional athletes, asthmatics and healthy controls. We also sought to determine whether acute treadmill exercise influences serum and EBC periostin.

METHODS

Study groups included 9 competitive swimmers, 10 mild-to-moderate asthmatics and 7 healthy controls. Athletes were assessed twice (in- and off-training period) while asthmatics and controls in one time-point. Data on demographics, allergy symptoms and exercise load were acquired through Allergy Questionnaire for Athletes (AQUA) and International Physical Activity Questionnaire (IPAQ). Serum and EBC were collected before and after treadmill exercise challenge.

RESULTS

Baseline serum periostin in swimmers during training period was significantly higher (5- to 7-fold) than in asthmatics (P = .01) and controls (P < .05). In EBC, lowest periostin levels were seen in athletes in-training as compared with off-training period (P < .01) and with asthmatics (P < .03). Acute bout of exercise did not induce significant changes neither in serum nor in EBC periostin in any group.

CONCLUSION

Increased serum, but not EBC, periostin levels in competitive athletes are probably because of permanently increased exercise load leading to stimulation, injury and regeneration of musculoskeletal tissues. Periostin may be considered marker of long-term exercise overload after confirmation in larger groups.

Winter ambient training conditions are associated with increased bronchial hyperreactivity and with shifts in serum innate immunity proteins in young competitive speed skaters

INTRODUCTION

Regular training modulates airway inflammation and modifies susceptibility to respiratory infections. The impact of exercise and ambient conditions on airway hyperreactivity and innate immunity has not been well studied. We aimed to assess exercise-related symptoms, lung function, airway hyperresponsiveness and innate immunity proteins in relation to meteorological conditions and exercise load in competitive athletes.

MATERIAL AND METHODS

Thirty-six speed skaters were assessed during winter (WTP) and summer (STP) periods. The control group comprised 22 non-exercising subjects. An allergy questionnaire for athletes (AQUA) and IPAQ (International Physical Activity Questionnaire) were used to assess symptoms and exercise. Meteorological parameters were acquired from World Meteorological Organization resources. Serum innate immunity proteins were measured by ELISA.

RESULTS

Exercise-associated respiratory symptoms were reported by 79.4% of skaters. Despite similar exercise load and lung parameters during both periods, positive methacholine challenge was more frequent during winter (p = 0.04). Heat shock protein HSPA1 and IL-1RA were significantly decreased during STP compared to WTP and controls. During WTP, IL-1RA was elevated in skaters reporting exercise-induced symptoms (p = 0.007). sCD14 was elevated in athletes versus controls in both periods (p < 0.05). HSPA1 was significantly higher in WTP compared to STP irrespective of presence of respiratory tract infections (RTIs). IL-1RA in WTP was elevated versus STP (p = 0.004) only in RTI-negative athletes. Serum IL-1RA negatively correlated with most meteorological parameters during WTP.

CONCLUSIONS

Ambient training conditions, but not training load, influence bronchial hyperreactivity and the innate immune response in competitive athletes assessed during winter. The protective effect of regular exercise against respiratory infections is associated with a shift in serum innate immunity proteins.

Acute and Chronic Effects of Endurance Running on Inflammatory Markers: A Systematic Review

In order to understand the effect of endurance running on inflammation, it is necessary to quantify the extent to which acute and chronic running affects inflammatory mediators. The aim of this study was to summarize the literature on the effects of endurance running on inflammation mediators. Electronic searches were conducted on PubMED and Science Direct with no limits of date and language of publication. Randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) investigating the acute and chronic effects of running on inflammation markers in runners were reviewed by two researchers for eligibility. The modified Downs and Black checklist for the assesssments of the methodological quality of studies was subsequently used. Fifty-one studies were finally included. There were no studies with elite athletes. Only two studies were chronic interventions. Results revealed that acute and chronic endurance running may affect anti- and pro-inflammatory markers but methodological differences between studies do not allow comparisons or generalization of the results. The information provided in this systematic review would help practitioners for better designing further studies while providing reference values for a better understanding of inflammatory responses after different running events. Further longitudinal studies are needed to identify the influence of training load parameters on inflammatory markers in runners of different levels and training background.