Acute effects of different degrees of ultra-endurance exercise on systemic inflammatory responses

Effects of ibuprofen during 42-km trail running on oxidative stress, muscle fatigue, muscle damage and performance: a randomized controlled trial

Up to 75% of marathon runners ingest non-steroidal anti-inflammatory drugs (NSAIDs) during competition. Despite the doubt whether or not they contribute to performance, the effect of NSAID in endurance sports is unclear. We evaluated the effect of ibuprofen (IBU) use on oxidative stress, muscle damage, physical performance, and vertical jump of runners participating in a 42-km-trail running. The sample consisted of 12 men randomly divided into 2 groups: a placebo group (placebo) and an ibuprofen group (IBG). A 400-mg IBU capsule was administered to the IBG 15 min prior to the start of the trial and during the course after 5 h. In the intergroup analysis, placebo 70.1% increase (p < 0.0001; Cohen's d = 4.77) of the thiobarbituric acid reactive substances (TBARS); the IBG exhibited a 31.46% increase of the sulphhydryl groups (SH) (p = 0.024, Cohen's d = 0.27), 55% of squat jump (SJ) (p < 0.01; Cohen's d = 1.41) with no significant effect on creatine kinase (CK), pace, speed, and finish time. In summary, IBU had positive evidence on oxidative stress and muscle fatigue, but had no effect on physical performance and muscle damage.

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.

Blood-Based Biomarkers for Managing Workload in Athletes: Considerations and Recommendations for Evidence-Based Use of Established Biomarkers

Blood-based biomarkers can provide an objective individualized measure of training load, recovery, and health status in order to reduce injury risk and maximize performance. Despite enormous potentials, especially owing to currently evolving technology, such as point-of-care testing, and advantages, in terms of objectivity and non-interference with the training process, there are several pitfalls in the use and interpretation of biomarkers. Confounding variables such as preanalytical conditions, inter-individual differences, or an individual chronic workload can lead to variance in resting levels. In addition, statistical considerations such as the detection of meaningful minimal changes are often neglected. The lack of generally applicable and individual reference levels further complicates the interpretation of level changes and thus load management via biomarkers. Here, the potentials and pitfalls of blood-based biomarkers are described, followed by an overview of established biomarkers currently used to support workload management. Creatine kinase is discussed in terms of its evidence for workload management to illustrate the limited applicability of established markers for workload management to date. We conclude with recommendations for best practices in the use and interpretation of biomarkers in a sport-specific context.

Can a basic solution activate the inflammatory reflex? A review of potential mechanisms, opportunities, and challenges

Stimulation of the inflammatory reflex (IR) is a promising strategy to treat systemic inflammatory disorders. However, this strategy is hindered by the cost and side effects of traditional IR activators. Recently, oral intake of sodium bicarbonate (NaHCO3) has been suggested to activate the IR, providing a safe and inexpensive alternative. Critically, the mechanisms whereby NaHCO3 might achieve this effect and more broadly the pathways underlying the IR remain poorly understood. Here, we argue that the recognition of NaHCO3 as a potential IR activator presents exciting clinical and research opportunities. To aid this quest, we provide an integrative review of our current knowledge of the neural and cellular pathways mediating the IR and discuss the status of physiological models of IR activation. From this vantage point, we derive testable hypotheses on potential mechanisms whereby NaHCO3 might stimulate the IR and compare NaHCO3 with classic IR activators. Elucidation of these mechanisms will help determine the therapeutic value of NaHCO3 as an IR activator and provide new insights into the IR circuitry.

Echocardiographic Assessment of Left Ventricular Function 10 Years after the Ultra-Endurance Running Event Eco-Trail de Paris® 2011

Background: Regular and moderate physical activity is beneficial for physical and mental health, resulting in an increase in life expectancy for both sexes. From a cardiovascular point of view, although the benefits of regular moderate physical exercise have been established, the long-term effects of repeated ultra-endurance running events are still unknown. Hypothesis: The aim of our study is to evaluate the 10-year evolution of the parameters of the left ventricular systolic and diastolic functions of amateur subjects regularly practising ultra-endurance running events using resting echocardiography. Study design: Cross-sectional study. Level of evidence: Level 3—non-randomized controlled cohort/follow-up study. Methods: The 66 participants who participated in the 2011 edition of the Eco-Trail de Paris® were contacted by e-mail. Demographic data, sports practice, and the results of an echocardiography scan carried out during the year 2021 evaluating left ventricular systolic and diastolic function variables were collected. Echographic variables from 2011 and 2021 were compared using the paired Student’s t-test. Results: Forty-six (70%) participants responded positively. Twenty (30%) participants could not be reached and were not analysed. Of the 46 respondents, 42 (91%) provided data from a trans-thoracic cardiac ultrasound performed in 2021. Over the past 10 years, the participants reported having completed an average of 4 ± 2 ultra-trails per year. No significant differences were observed between left ventricular diastolic and systolic echocardiographic parameters between the years 2011 and 2021. Conclusions: Among amateur participants, long-distance running is not associated with an alteration in the echocardiographic parameters of resting left ventricular systolic and diastolic function after 10 years of practice. Clinical relevance: Long-term long-distance running practice is not associated with left ventricular cardiac function alteration. These results suggest a potential adaptation role of the cardiovascular system to regular and moderate long-distance running practice.

Relationship between Exercise Intensity and IL-6 Increase during an 80 km Long-Distance Running Race

Background: IL-6 plasma concentration (IL-6PC) reflects the systemic inflammation related to exercise intensity level. This study aims to describe the IL-6PC kinetics during a long-distance running race. IL-6PC was measured in 20 male runners before (0 km), at each refreshment point (at 21 and 53 km, i.e., k₂₁ and k₅₃, respectively) and at the end of an 80 km long-distance run (k₈₀). Methods: IL-6PC variations (absolute and relative values in each of the three sections (S)) were calculated over S1 (0_k₂₁), S2 (k₂₁_k₅₃) and S3 (k₅₃_k₈₀) and compared with the exercise intensity (duration*race speed) within each section. Results: The mean IL-6PC increased during the run: 2.1 ± 0.6 ng.L⁻¹ at 0 km, 21.0 ± 11.3 ng.L⁻¹ at k₂₁, 38.9 ± 13.0 ng.L⁻¹ at k₅₃ and 49.8 ± 11.9 ng.L⁻¹ at k₈₀. Exercise intensity increased between S1 (24.2 ± 0.5) and S2 (51.9 ± 3.2) (p = 0.04) but not between S2 and S3 (67.4 ± 4.5) (p = 0.69). IL-6PC variation was associated with exercise intensity within S1 (p = 0.03) and S2 (p = 2 × 10⁻³) and showed at least a trend within S3 (p = 0.06). Conclusions: IL-6PC increases that occur during the early stages of a long-distance run are associated with the running intensity, and then IL-6PC remain stable after the reduction in intensity related to the decrease in running speed.

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.

Recent Progress in Applicability of Exercise Immunology and Inflammation Research to Sports Nutrition

This article focuses on how nutrition may help prevent and/or assist with recovery from the harmful effects of strenuous acute exercise and physical training (decreased immunity, organ injury, inflammation, oxidative stress, and fatigue), with a focus on nutritional supplements. First, the effects of ketogenic diets on metabolism and inflammation are considered. Second, the effects of various supplements on immune function are discussed, including antioxidant defense modulators (vitamin C, sulforaphane, taheebo), and inflammation reducers (colostrum and hyperimmunized milk). Third, how 3-hydroxy-3-methyl butyrate monohydrate (HMB) may offset muscle damage is reviewed. Fourth and finally, the relationship between exercise, nutrition and COVID-19 infection is briefly mentioned. While additional verification of the safety and efficacy of these supplements is still necessary, current evidence suggests that these supplements have potential applications for health promotion and disease prevention among athletes and more diverse populations.

Paradoxical Relationships between Serum 25(OH)D and Ferritin with Body Composition and Burnout: Variation by Sex and Sports Team

Adequate serum vitamin D and iron levels are thought to influence physical training adaptations and mood positively. The primary purpose of this prospective, observational study was to investigate relationships between serum 25-OH vitamin D/25(OH)D and serum ferritin levels with body composition and athlete burnout symptoms. Seventy-three collegiate athletes (female: n = 49; male: n = 24) from indoor (swimming, basketball) and outdoor (soccer, cross-country) sports were tested pre-season and post-season for serum 25(OH)D and serum ferritin (nutrient biomarkers) via venipuncture; body composition (total lean mass, bone mineral density/BMD, and % body fat) via dual energy X-ray absorptiometry (DXA) scans; and athlete burnout symptoms (post-season) via the athlete burnout questionnaire (ABQ). When male and female cohorts were combined, significant correlations (Pearson’s r) were noted between pre-season serum 25(OH)D versus the change (∆: post-season minus pre-season) in both BMD (r = −0.34; p = 0.0003) and % body fat (r = −0.28; p = 0.015). Serum ferritin ∆ was significantly associated with lean mass ∆ (r = −0.34; p = 0.003). For burnout symptoms, serum 25(OH)D ∆ significantly explained 20.6% of the variance for devaluation of the sport in the male cohort only. Across time, serum 25(OH)D levels decreased while serum ferritin levels increased, non-significantly, in both males and females. Relationships between nutrient biomarkers and body composition were opposite of physiological expectations.

Exercise-Induced Hyperhomocysteinemia Is Not Related to Oxidative Damage or Impaired Vascular Function in Amateur Middle-Aged Runners under Controlled Nutritional Intake

To determine the influence of different doses of maximal acute exercise on the kinetics of plasma homocysteine (tHcy) and its relationship with oxidative status and vascular function, nine recreational runners completed a 10 km race (10K) and a marathon (M). Blood samples were collected before (Basal), immediately post-exercise (Post0), and after 24 h (Post24). Nutritional intake was controlled at each sample point. A significant increase in tHcy was observed after both races, higher after M. Basal levels were recovered at Post24 after 10K, but remained elevated at Post 24 for M. A significant decrease in GSH/GSSG ratio was observed in Post0, especially marked after M. Furthermore, this increase in pro-oxidant status remained at Post24 only after M. Other oxidative status markers failed to confirm this exercise-induced pro-oxidant status except glutathione peroxidase activity that was lower in Post24 compared to Basal in 10K and in Post0 and Post24 in M. No statistical correlation was found between oxidative markers and tHcy. No significant changes were observed in the concentration of endothelial cell adhesion molecules (VCAM-1 and E-Selectin) and VEGF. In conclusion, tHcy increases in an exercise–dose–response fashion but is not related to endothelial dysfunction mediated by oxidative stress mechanisms.

Pain sensitivity increases more in younger runners during an ultra-marathon

OBJECTIVES

Ultra-endurance research interest has increased in parallel with an increased worldwide participation in these extreme activities. Pain-related data for the growing population of ultra-endurance athletes, however, is insufficient. More data is especially needed regarding the variation in the aging populations of these athletes. We have previously shown that peripheral and central pain sensitivity increases during an ultra-marathon. To further clarify these changes in pain sensitivity during ultra-endurance competition we investigated these variations in two age populations: Younger runners ≤ 39-year-old (younger) and an older group of runners being ≥ 40 years of age (older).

METHODS

Subjects were recruited from ultra-marathon competitions held over a three-year period in Florida, USA. All courses were flat with either hard macadam surface or soft sandy trails; run in hot, humid weather conditions. Pressure pain threshold (PPT) was measured with a pressure algometer on the distal, dominant arm before and immediately after an ultra-marathon. Conditioned pain modulation (CPM) was also measured pre and post, immediately after the PPT by placing the non-dominant hand in a cold-water bath maintained at 13.5 ± 1.5 °C. The difference between the pre and post measurements for both PPT and CPM were calculated and referred to as ΔPPT and ΔCPM, respectively for analysis. Data were analyzed with a Mixed 2 × 2 (Within X Between) MANOVA.

RESULTS

Both PPT and CPM decreased during the ultra-marathons (p<0.05) in the younger group of runners. In the older runners there was not a statistically significant decrease in PPT during the ultramarathons whereas CPM did significantly decrease statistically (p=0.031). The ΔPPT was less in the older group compared to the younger group (p=0.018). The difference between the younger and older groups ΔCPM approached statistical significance at p=0.093.

CONCLUSIONS

This statistical evidence suggests that the overall increase in peripheral and possibly central pain sensitivity was different between our age groups. Pain sensitivity during the ultra-marathon increased more in our younger group of runners than in our older group. This study suggests that there is an unidentified factor in an older population of ultra-marathon runners that results in an attenuated increase in pain sensitivity during an ultra-endurance activity. These factors may include a decreased innate immune response, lower fitness level, lower exertion during the ultra-marathon, variation in endorphin, enkephalin, endocannabinoid and psychological factors in the older age runners.

Acute Changes in Interleukin-6 Level During Four Days of Long-Distance Walking

Background

Interleukin 6 (IL-6) has an inflammatory effect, and its concentration in serum increases during exercise. However, no studies have assessed acute changes in IL-6 concentration after consecutive days of extreme and long-term exercise.

Objective

This study aimed to assess acute changes in serum IL-6 concentration during four days of long-distance walking.

Methods

This prospective observational study assessed 25 athletes (aged 44.8 ± 9.1 years), who covered a total of 251 km in four days. Blood samples were collected daily to assess serum IL-6 concentrations. Repeated-measures analysis of variance (with Bonferroni’s post hoc test) and the Kruskal–Wallis H-test (with Dunn’s post hoc test) were used to investigate the differences between the measures.

Results

The serum IL-6 concentrations were higher on the four days of walking (1st day: 26.8 ± 14.8; 2nd day: 14 ± 7.4; 3rd day: 9.4 ± 10.8; 4th day: 4.5 ± 0.2 pg/mL) when compared to pre-walk values (pre-walk: 2.2 ± 2.1 pg/mL; p < 0.001). On the first day, there was a tenfold increase compared to the pre-walk value.

Conclusion

The inflammatory response increased the serum concentration of IL-6 after four days of exercise. With the passing of days, there were reductions but not to baseline values.

Exercise but Not Supplemental Dietary Tryptophan Influences Heart Rate and Respiratory Rate in Sled Dogs

Tryptophan (Trp), an indispensable amino acid for dogs, is the precursor of serotonin, a neurotransmitter with a variety of effects throughout the body, including the ability to modulate cardiac and pulmonary activity. This study aimed to investigate the effects of a 12-week incremental exercise regimen and supplemental dietary Trp on heart rate (HR) and respiratory rate (RR) in client-owned sled dogs. Sixteen Siberian huskies were randomly allocated to either treatment or control diet groups. Both groups were fed a control diet (Trp to large neutral amino acid ratio of 0.047:1); however, treatment dogs received a Trp supplement to achieve a Trp to large neutral amino acid ratio of 0.075:1. Every three weeks, external telemetry equipment was used to non-invasively measure and record HR and RR at a resting, working, and post-exercise state in a controlled exercise challenge. A mixed model was used to test differences between diet, activity parameter, and week. Dietary Trp supplementation had no effect on HR or RR. Independent of diet, resting, working, post-exercise HR, and time to recover post-exercise HR decreased from week −1 to week 11 (p < 0.05). Resting HR had the greatest reduction from week −1 to week 11 (21%, p < 0.05). Working RR did not change with exercise (p > 0.10), but rRR and postRR decreased from week −1 to week 11 (p < 0.05). These data suggest that the exercise regimen the dogs were subjected to may have positively impacted the dogs’ capacity to sustain aerobic exercise, whereas Trp supplementation had no effect on HR or RR.

Acute Effects of Triathlon Race on Oxidative Stress Biomarkers

The response to strenuous exercise was investigated by reactive oxygen species (ROS) production, oxidative damage, thiol redox status, and inflammation assessments in 32 enrolled triathlon athletes (41.9 ± 7.9 yrs) during Ironman® (IR), or half Ironman® (HIR) competition. In biological samples, inflammatory cytokines, aminothiols (glutathione (GSH), homocysteine (Hcy), cysteine (Cys), and cysteinylglycine (CysGly)), creatinine and neopterin, oxidative stress (OxS) biomarkers (protein carbonyl (PC), thiobarbituric acid-reactive substances (TBARS)), and ROS were assessed. Thirteen HIR and fourteen IR athletes finished the race. Postrace, ROS (HIR +20%; IR +28%; p < 0.0001), TBARS (HIR +57%; IR +101%), PC (HIR +101%; IR +130%) and urinary neopterin (HIR +19%, IR +27%) significantly (range p < 0.05-0.0001) increased. Moreover, HIR showed an increase in total Cys +28%, while IR showed total aminothiols, Cys, Hcy, CysGly, and GSH increase by +48, +30, +58, and +158%, respectively (range p < 0.05-0.0001). ROS production was significantly correlated with TBARS and PC (R 2 = 0.38 and R 2 = 0.40; p < 0.0001) and aminothiols levels (range R 2 = 0.17-0.47; range p < 0.01-0.0001). In particular, ROS was directly correlated with the athletes' age (R 2 = 0.19; p < 0.05), with ultraendurance years of training (R 2 = 0.18; p < 0.05) and the days/week training activity (R 2 = 0.16; p < 0.05). Finally, the days/week training activity (hours/in the last 2 weeks) was found inversely correlated with the IL-6 postrace (R 2 = -0.21; p < 0.01). A strenuous performance, the Ironman® distance triathlon competition, alters the oxidant/antioxidant balance through a great OxS response that is directly correlated to the inflammatory parameters; furthermore, the obtained data suggest that an appropriate training time has to be selected in order to achieve the lowest ROS production and IL-6 concentration at the same time.

Acute kidney injury during an ultra-distance race

Purpose

Previous studies have noted consequences of ultra-distance trail running on health, but few studies are available regarding the temporal variations of renal biomarker injury during the running. The aim of this study was to assess the of kidney function parameters temporal variation during and on short-term after an ultra-distance race.

Methods

We performed an observational study with 47 subjects participating in an ultra-distance race (80 km). Urine (47 subjects) and blood (21 subjects) samples were serially collected before (baseline—km 0), during (21 and 53 km), on arrival (80 km), and 9 days after the race (d9).

Results

Mean serum creatinine increased during the race from 90±14 μmol/L (km0) to 136±32 μmol/L (km 80—p<0.0001) corresponding to a 52% increase. Mean creatininuria progressively increased from 4.7±4.5 mmol/L (km 0) to 22.8±12.0 mmol/L (km 80) (p<0.0001). Both urinary biomarkers (Neutrophil Gelatinase Associated Lipocalin and Kidney Injury Molecule-1) of acute kidney injury (AKI) progressively increased during the race (p<0.05 vs baseline). However, after adjustment to urine dilution by urine creatinine, no significant changes remained (p>0.05). On day 9, no significant difference remains in blood and urine biomarkers compared to their respective baseline levels.

Conclusions

During an ultra-distance race, despite an acute and transient increase in the serum creatinine levels, urinary biomarkers of AKI displayed only limited changes with a complete regression on day 9. These results suggest the absence of the short-term impact of an ultra-distance race kidney function.

Acute Cardiovascular Adaptation to Strenuous Exercise: An Integrative Ultrasound Study

OBJECTIVES

The aim of this study was to evaluate the acute effects of participation in an Ironman distance triathlon competition on arterial function by ultrasound, in relation to cardiac function and body water content.

METHODS

Twenty-eight male triathletes participating in an Ironman distance competition underwent carotid, femoral, and cardiac ultrasound examinations. Moreover, the presence of extravascular lung water was identified by lung echo B-lines (echogenic coherent wedge-shaped signal with a narrow origin from the hyperechoic pleural line) at rest and within 20 minutes of arrival.

RESULTS

At the end of the competition, athletes showed an increased heart rate (mean ± SD, from 60.2 ± 13.1 to 82.8 ± 15.6 beats/min; P < .0001) and unchanged mean blood pressure (from 93 ± 14 to 91 ± 10 mm Hg; P > .05) in the presence of negligible dehydration (total body water from 48.0 ± 4.0 to 46.5 ± 3.9 kg; P > .05). Cardiac output increased (from 5.5 ± 1.2 to 6.7 ± 2.4 L/min; P < .05) in the presence of an unchanged stroke volume (from 64 ± 14 to 59 ± 16 mL; P > .05) and unchanged left ventricular elastance (from 1.52 ± 0.48 to 1.39 ± 0.48 mm Hg/mL/m² ; P > .05). The mean carotid diameter increased (from 7.19 ± 0.65 to 7.61 ± 0.76 mm; P < .05), whereas the mean femoral diameter was unchanged at the end of the competition (from 10.41 ± 0.83 to 10.49 ± 0.82 mm; P > .05). Carotid intima-media thickness was significantly reduced (from 537 ± 70 to 495 ± 70 μm; P < .05), whereas B-lines increased significantly after the competition (from 1 [0-4] to 12 [5-23]; P < .0001).

CONCLUSIONS

These data suggest different acute functional adaptation in central arteries with respect to peripheral leg vessels.

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.

Mountain Cycling Ultramarathon Effects on Inflammatory and Hemoglobin Responses

PURPOSE

This study aimed to analyze the cumulative physiological burden of repetitive, strenuous exercise held during mountain cycling ultramarathon on regulatory mechanisms of hemoglobin degradation.

METHODS

Fifty-five nonprofessional athletes (mean age, 44.8 ± 7.1 yr) participating in a 9-consecutive-day mountain cycling ultramarathon (TransPortugal) underwent anthropometric, hematological, and biochemical assessments before and immediately after the race. Participants were further stratified as completers (nine courses) or noncompleters and were divided according to the time they took to complete the race. The heme oxygenase-1 (HMOX1) functional genetic polymorphism and haptoglobin (HP) phenotypic variants were also analyzed.

RESULTS

Total leukocytes, neutrophil count, and monocyte count increased, whereas decreases in erythrocyte counts and hemoglobin were found between pre- and postultramarathon. Circulating haptoglobin (Hp) was increased, whereas its soluble receptor (sCD163) decreased. Athletes who completed all nine courses presented with increased leukocyte, neutrophil, and erythrocyte counts, as well as hemoglobin, red cell distribution width, total bilirubin, and total cholesterol levels. High-sensitivity C-reactive protein and Hp decreased in comparison with noncompleters. HMOX1 and HP genetic polymorphisms were associated with biochemical profile, notably with Hp levels. Analysis of covariance showed a significant effect of HP phenotype in Hp circulating levels at the end of race and on the magnitude of variation from pre- to postrace.

CONCLUSIONS

Present findings support a comodulatory influence of genetic- and exercise-associated factors on resulting inflammatory and hemoglobin catabolic marker Hp after highly demanding endurance exercise.

Central and peripheral pain sensitization during an ultra-marathon competition

Background and aims

The participation in ultra-marathons and other ultra-endurance events has increased exponentially over the past decade. There is insufficient data on variation in pain mechanisms in exercise overall but especially in the ultra-endurance athlete population. To further understand peripheral and central pain sensitization we have investigated pressure pain threshold and conditioned pain modulation during three separate ultra-marathon competitions.

Methods

Each ultra-marathon investigated was held in the state of Florida, USA, over flat, sandy and paved surfaces under generally warm to hot, humid conditions. Pressure pain threshold was measured utilizing a Baseline © Dolorimeter. The blunt end of the dolorimeter stylus was placed onto the distal dominant arm, equidistant between the distal radius and ulna, three times in a blinded manner to insure that the testing technician did not influence the subject’s responses. Conditioned pain modulation was measured immediately after the PPT measures by placing the non-dominant hand in a cool water bath maintained at 15°C. The same dolorimeter measurement was repeated two more times on the dominant arm while the non-dominant hand remained in the water. Data was analyzed with a paired t-test.

Results

Pressure pain threshold was significantly decreased (p<0.05) at 25, 50 and 100 miles. Conditioned pain modulation was also significantly decreased (p<0.05) at 25, 50 and 100 miles of an ultra-marathon competition.

Conclusions

Together these data suggest an increased peripheral and/or central pain sensitization starting at 25 miles and continuing throughout an ultra-marathon competition run in these conditions. This is the first study that provides evidence of a decreased peripheral pain threshold and decreased central pain inhibition from ultra-marathon running. Decreases in both the peripheral pain threshold and central inhibition may result from nociceptor plasticity, central sensitization or a combination of both.

Implications

Based on previous research that has indicated a central sensitization resulting from inflammation and the well-documented inflammatory response to the rigors of ultra-marathon competition, we suggest the decreased peripheral pain threshold and decreased descending pain inhibition results from this inflammatory response of running an ultra-marathon.

The level of physical training modulates cytokine levels through P2X7 receptor in healthy subjects

INTRODUCTION

The P2X7 receptor-NLRP3 inflammasome complex (P2X7R-Infl) regulates inflammatory and immune responses. Physical exercise modulates heat-shock proteins (Hsps), influencing cytokine levels and oxidative stress; Hsp72 triggers P2X7R-Infl-dependent responses.

SUBJECTS AND METHODS

We studied the effect of a single bout of maximal exercise on lymphomonocyte expression of P2X7R, NLRP3, caspase-1, NF-kB and Hsp72 and circulating levels of IL-1β, IL-18 and MCP-1, all modulated by P2X7R-Infl, in healthy sedentary (SED), trained (ATH), endurance (END) male individuals.

RESULTS

Baseline P2X7R, NLRP3 and Caspase-1 expression progressively increased from SED to ATH and END; NF-kβ showed the same trend. Hsp72 did not differ among groups. Acute exercise strongly reduced P2X7R in all participants, irrespective of their degree of physical training. Inflammasome responses differed across groups: in SED, NLRP3 and Caspase-1 increased; in ATH, NLRP3 reduced and caspase-1 did not vary; in END, NLRP3 and Caspase-1 declined. Baseline IL-1β, higher in END, was unmodified after exercise; IL-18 decreased; MCP-1 doubled in SED, did not vary in ATH, declined in END. In the whole study population, significant direct relationships emerged between P2X7R expression and IL-1β, IL-18, MCP-1 levels, all P < .001; also Caspase-1 related with these markers. A multivariate analysis showed age, BMI and P2X7R as determinants of postexercise IL-1β levels.

CONCLUSION

Endurance show higher P2X7R-Infl expression and function vs SED and ATH; however, maximal exercise determines prevailing pro-inflammatory vs anti-inflammatory responses in untrained and trained participants, respectively, highlighting a likely cause-effect relationship between degree of physical activity and P2X7R-Infl-mediated responses.

Is irisin the new player in exercise-induced adaptations or not? A 2017 update

Irisin is produced by a proteolytic cleavage of fibronectin type III domain-containing protein 5 (FNDC5) and has emerged as a potential mediator of exercise-induced energy metabolism. The purpose of this study was to review the results of studies that investigated irisin responses to acute and chronic exercise and provide an update. A comprehensive search in the databases of MEDLINE was performed (74 exercise studies). The focus of the analysis was on data concerning FNDC5 mRNA expression in skeletal muscle and circulating irisin concentration relatively to exercise mode, intensity, frequency and duration and the characteristics of the sample used. Circulating irisin levels may either not relate to FNDC5 transcription or expression of the later precedes irisin rise in the blood. Acute speed/strength and endurance exercise protocols represent potent stimuli for irisin release if they are characterized by adequate intensity and/or duration. There are no reports regarding irisin responses to field sport activities. Although animal studies suggest that irisin may also respond to systematic exercise training, the majority of human studies has produced contradictory results. Certain methodological issues need to be considered here such as the analytical assays used to measure irisin concentration in the circulation. Results may also be affected by subjects’ age, conditioning status and exercise intensity. The role of irisin as a moderator of energy metabolism during exercise remains to be seen.

Can half-marathon affect overall health? The yin-yang of sport

Physical activity improves overall health and counteracts metabolic pathologies. Adipose tissue and bone are important key targets of exercise; the prevalence of diseases associated with suboptimal physical activity levels has increased in recent times as a result of lifestyle changes. Mesenchymal stem cells (MSCs) differentiation in either osteogenic or adipogenic lineage is regulated by many factors. Particularly, the expression of master genes such as RUNX2 and PPARγ2 is essential for MSC commitment to osteogenic or adipogenic differentiation, respectively. Besides various positive effects on health, some authors have reported stressful outcomes as a consequence of endurance in physical activity. We looked for further clues about MSCs differentiation and serum proteins modulation studying the effects of half marathon in runners by means of gene expression analyses and a proteomic approach. Our results demonstrated an increase in osteogenic commitment and a reduction in adipogenic commitment of MSCs. In addition, for the first time we have analyzed the proteomic profile changes in runners after half-marathon activity in order to survey the related systemic adjustments. The shotgun proteomic approach, performed through the immuno-depletion of the 14 most abundant serum proteins, allowed the identification of 23 modulated proteins after the half marathon. Interestingly, proteomic data showed the activation of both inflammatory response and detoxification process. Moreover, the involvement of pathways associated to immune response, lipid transport and coagulation, was elicited. Notably, positive and negative effects may be strictly linked. Data are available via ProteomeXchange with identifier PXD006704.

SIGNIFICANCE

We describe gene expression and proteomic studies aiming to an in-depth understanding of half-marathon effects on bone and adipogenic differentiation as well as biological phenomena involved in sport activity. We believe that this novel approach suggests the physical effects on overall health and show the different pathways involved during half marathon. Contents of the paper have not been published or submitted for publication elsewhere. The authors declare no conflict of interest.

Effects of physical activity on the link between PGC-1a and FNDC5 in muscle, circulating Ιrisin and UCP1 of white adipocytes in humans: A systematic review

Background: Exercise may activate a brown adipose-like phenotype in white adipose tissue. The aim of this systematic review was to identify the effects of physical activity on the link between peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1a) and fibronectin type III domain-containing protein 5 (FNDC5) in muscle, circulating Irisin and uncoupling protein one (UCP1) of white adipocytes in humans. Methods: Two databases (PubMed 1966 to 08/2016 and EMBASE 1974 to 08/2016) were searched using an appropriate algorithm. We included articles that examined physical activity and/or exercise in humans that met the following criteria: a) PGC-1a in conjunction with FNDC5 measurements, and b) FNDC5 and/or circulating Irisin and/or UCP1 levels in white adipocytes. Results: We included 51 studies (12 randomised controlled trials) with 2474 participants. Out of the 51 studies, 16 examined PGC-1a and FNDC5 in response to exercise, and only four found increases in both PGC-1a and FNDC5 mRNA and one showed increased FNDC5 mRNA. In total, 22 out of 45 studies that examined circulating Irisin in response to exercise showed increased concentrations when ELISA techniques were used; two studies also revealed increased Irisin levels measured via mass spectrometry. Three studies showed a positive association of circulating Irisin with physical activity levels. One study found no exercise effects on UCP1 mRNA in white adipocytes. Conclusions: The effects of physical activity on the link between PGC-1a, FNDC5 mRNA in muscle and UCP1 in white human adipocytes has attracted little scientific attention. Current methods for Irisin identification lack precision and, therefore, the existing evidence does not allow for conclusions to be made regarding Irisin responses to physical activity. We found a contrast between standardised review methods and accuracy of the measurements used. This should be considered in future systematic reviews.

Effects of physical activity on the link between PGC-1a and FNDC5 in muscle, circulating Ιrisin and UCP1 of white adipocytes in humans: A systematic review

Background: Exercise may activate a brown adipose-like phenotype in white adipose tissue. The aim of this systematic review was to identify the effects of physical activity on the link between peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1a) and fibronectin type III domain-containing protein 5 (FNDC5) in muscle, circulating Irisin and uncoupling protein one (UCP1) of white adipocytes in humans. Methods: Two databases (PubMed 1966 to 08/2016 and EMBASE 1974 to 08/2016) were searched using an appropriate algorithm. We included articles that examined physical activity and/or exercise in humans that met the following criteria: a) PGC-1a in conjunction with FNDC5 measurements, and b) FNDC5 and/or circulating Irisin and/or UCP1 levels in white adipocytes. Results: We included 51 studies (12 randomised controlled trials) with 2474 participants. Out of the 51 studies, 16 examined PGC-1a and FNDC5 in response to exercise, and only four found increases in both PGC-1a and FNDC5 mRNA and one showed increased FNDC5 mRNA. In total, 22 out of 45 studies that examined circulating Irisin in response to exercise showed increased concentrations when ELISA techniques were used; two studies also revealed increased Irisin levels measured via mass spectrometry. Three studies showed a positive association of circulating Irisin with physical activity levels. One study found no exercise effects on UCP1 mRNA in white adipocytes. Conclusions: The effects of physical activity on the link between PGC-1a, FNDC5 mRNA in muscle and UCP1 in white human adipocytes has attracted little scientific attention. Current methods for Irisin identification lack precision and, therefore, the existing evidence does not allow for conclusions to be made regarding Irisin responses to physical activity. We found a contrast between standardised review methods and accuracy of the measurements used. This should be considered in future systematic reviews.

Physical activity and exercise attenuate neuroinflammation in neurological diseases

Major depressive disorder (MDD), schizophrenia (SCH), Alzheimer's disease (AD), and Parkinson's disease (PD) are devastating neurological disorders, which increasingly contribute to global morbidity and mortality. Although the pathogenic mechanisms of these conditions are quite diverse, chronic neuroinflammation is one underlying feature shared by all these diseases. Even though the specific root causes of these diseases remain to be identified, evidence indicates that the observed neuroinflammation is initiated by unique pathological features associated with each specific disease. If the initial acute inflammation is not resolved, a chronic neuroinflammatory state develops and ultimately contributes to disease progression. Chronic neuroinflammation is characterized by adverse and non-specific activation of glial cells, which can lead to collateral damage of nearby neurons and other glia. This misdirected neuroinflammatory response is hypothesized to contribute to neuropathology in MDD, SCH, AD, and PD. Physical activity (PA), which is critical for maintenance of whole body and brain health, may also beneficially modify neuroimmune responses. Since PA has neuroimmune-modifying properties, and the common underlying feature of MDD, SCH, AD, and PD is chronic neuroinflammation, we hypothesize that PA could minimize brain diseases by modifying glia-mediated neuroinflammation. This review highlights current evidence supporting the disease-altering potential of PA and exercise through modifications of neuroimmune responses, specifically in MDD, SCH, AD and PD.

Exercise promotes IL-6 release from legs in older men with minor response to unilateral immobilization

Physical inactivity is a major contributor to low-grade systemic inflammation. Most of the studies characterizing interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) release from exercising legs have been done in young, healthy men, but studies on inactivity in older people are lacking. The impact of 14 days of one-leg immobilization (IM) on IL-6 and TNF-α release during exercise in comparison to the contralateral control (CON) leg was investigated. Fifteen healthy men (age 68.1 ± 1.1 year (mean ± SEM); BMI 27.0 ± 0.4 kg·m(2); VO2max 33.3 ± 1.6 ml·kg(‒1)·min(‒1)) performed 45 min of two-leg dynamic knee extensor exercise at 19.5 ± 0.9 W. Arterial and femoral venous blood samples from the CON and the IM legs were collected every 15 min during exercise, and thigh blood flow was measured with ultrasound Doppler. Arterial plasma IL-6 concentration increased with exercise (rest vs. 45 min, main effect p < .05). IL-6 release increased with exercise (rest vs. 30 min, main effect p < .05). Furthermore, IL-6 release was borderline (main effect, p = .085, effect size 0.28) higher in the IM leg compared to the CON leg (288 (95% CI: 213-373) vs. 220 (95% CI: 152-299) pg·min(‒1), respectively). There was no release of TNF-α in either leg and arterial concentrations remained unchanged during exercise (p > .05). In conclusion, exercise induces more pronounced IL-6 secretion in healthy older men. Two weeks of unilateral immobilization on the other hand had only a minor influence on IL-6 release. Neither immobilization nor exercise had an effect on TNF-α release across the working legs in older men.

Effects of Mountain Ultra-Marathon Running on ROS Production and Oxidative Damage by Micro-Invasive Analytic Techniques

PURPOSE

Aiming to gain a detailed insight into the physiological mechanisms involved under extreme conditions, a group of experienced ultra-marathon runners, performing the mountain Tor des Géants® ultra-marathon: 330 km trail-run in Valle d'Aosta, 24000 m of positive and negative elevation changes, was monitored. ROS production rate, antioxidant capacity, oxidative damage and inflammation markers were assessed, adopting micro-invasive analytic techniques.

METHODS

Forty-six male athletes (45.04±8.75 yr, 72.6±8.4 kg, 1.76±0.05 m) were tested. Capillary blood and urine were collected before (Pre-), in the middle (Middle-) and immediately after (Post-) Race. Samples were analyzed for: Reactive Oxygen Species (ROS) production by Electron Paramagnetic Resonance; Antioxidant Capacity by Electrochemistry; oxidative damage (8-hydroxy-2-deoxy Guanosine: 8-OH-dG; 8-isoprostane: 8-isoPGF2α) and nitric oxide metabolites by enzymatic assays; inflammatory biomarkers (plasma and urine interleukin-6: IL-6-P and IL-6-U) by enzyme-linked immunosorbent assays (ELISA); Creatinine and Neopterin by HPLC, hematologic (lactate, glucose and hematocrit) and urine parameters by standard analyses.

RESULTS

Twenty-five athletes finished the race, while twenty-one dropped out of it. A significant increase (Post-Race vs Pre) of the ROS production rate (2.20±0.27 vs 1.65±0.22 μmol.min-1), oxidative damage biomarkers (8-OH-dG: 6.32±2.38 vs 4.16±1.25 ng.mg-1 Creatinine and 8-isoPGF2α: 1404.0±518.30 vs 822.51±448.91 pg.mg-1Creatinine), inflammatory state (IL-6-P: 66.42±36.92 vs 1.29±0.54 pg.mL-1 and IL-6-U: 1.33±0.56 vs 0.71±0.17 pg.mL1) and lactate production (+190%), associated with a decrease of both antioxidant capacity (-7%) and renal function (i.e. Creatinine level +76%) was found.

CONCLUSIONS

The used micro-invasive analytic methods allowed us to perform most of them before, during and immediately after the race directly in the field, by passing the need of storing and transporting samples for further analysis. Considered altogether the investigated variables showed up that exhaustive and prolonged exercise not only promotes the generation of ROS but also induces oxidative stress, transient renal impairment and inflammation.

Effect of whey supplementation on circulating C-reactive protein: a meta-analysis of randomized controlled trials

Whey supplementation is beneficial for human health, possibly by reducing the circulating C-reactive protein (CRP) level, a sensitive marker of inflammation. Thus, a meta-analysis of randomized controlled trials was conducted to evaluate their relationship. A systematic literature search was conducted in July, 2014, to identify eligible studies. Either a fixed-effects model or a random-effects model was used to calculate pooled effects. The meta-analysis results of nine trials showed a slight, but no significant, reduction of 0.42 mg/L (95% CI −0.96, 0.13) in CRP level with the supplementation of whey protein and its derivates. Relatively high heterogeneity across studies was observed. Subgroup analyses showed that whey significantly lowered CRP by 0.72 mg/L (95% CI −0.97, −0.47) among trials with a daily whey dose ≥20 g/day and by 0.67 mg/L (95% CI −1.21, −0.14) among trials with baseline CRP ≥3 mg/L. Meta-regression analysis revealed that the baseline CRP level was a potential effect modifier of whey supplementation in reducing CRP. In conclusion, our meta-analysis did not find sufficient evidence that whey and its derivates elicited a beneficial effect in reducing circulating CRP. However, they may significantly reduce CRP among participants with highly supplemental doses or increased baseline CRP levels.