Effect of exercise intensity on the cytokine response to an acute bout of running

Can Methamphetamine-Induced Cardiotoxicity be Ameliorated by Aerobic Training and Nutrition Bio-shield Superfood Supplementation in Rats After Withdrawal?

The abuse of methamphetamine is a significant threat to cardiovascular health and has detrimental effects on the myocardium. The present study aims to explore potential interventions that can mitigate myocardial pyroptosis in rats following methamphetamine withdrawal. A total of 104 male Wistar rats were randomly assigned to eight groups. The rats underwent a methamphetamine administration protocol, receiving intraperitoneal injections of 10 mg/kg during the 1st week, followed by a weekly dose escalation of 1 mg/kg from the second to the 6th week and two times per day. Concurrently, the rats engaged in 6 weeks of moderate-intensity treadmill aerobic training, lasting 60 min per day, 5 days a week. Simultaneously, the Nutrition bio-shield Superfood (NBS) supplement was administered at a dosage of 25 g/kg daily for 6 weeks. The study assessed the expression levels of Caspase-1, Interleukin-1beta (IL-1β), and Interleukin-18 (IL-18) genes in myocardial tissue. Data analysis utilized a one-way analysis of variance (p ≤ 0.05). The findings revealed that methamphetamine usage significantly elevated the expression of Caspase-1, IL-1β, and IL-18 genes (p ≤ 0.05). Conversely, methamphetamine withdrawal led to a notable reduction in the expression of these genes (p ≤ 0.05). Noteworthy reductions in Caspase-1, IL-1β, and IL-18 expression were observed following aerobic training, supplementation, and the combined approach (p ≤ 0.05). The chronic use of methamphetamine was associated with cardiac tissue damage. This study highlights the potential of aerobic training and NBS Superfood supplementation in mitigating the harmful effects of methamphetamine-induced myocardial pyroptosis. The observed reductions in gene expression levels indicate promising interventions to address the cardiovascular consequences of methamphetamine abuse. The findings of this study suggest that a combination of aerobic exercise and NBS Superfood supplementation can provide a promising approach to mitigate the deleterious effects of methamphetamine on the heart. These findings can be useful for healthcare professionals and policymakers to design effective interventions to prevent and manage the adverse effects of methamphetamine abuse.

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.

Acute effect of exercise intensity on circulating FGF-21, FSTL-1, cathepsin B, and BDNF in young men

BACKGROUND/OBJECTIVES

Exercise intensity is potentially an important regulator of various exerkines secretion, but the optimal exercise intensity to increase and sustain exerkines levels, including FGF-21, FSTL-1, cathepsin B, and BDNF in humans, has not yet been fully elucidated. This study aimed to examine the circulating levels of FGF-21, FSTL-1, cathepsin B, and BDNF according to the exercise intensity.

METHODS

Nine young men (24.0 ± 0.4 years old) performed 4 different experimental sessions at 1-week intervals: 1) a control session (CTRL; no exercise); 2) moderate-intensity continuous exercise (MICE, 55% HRR); 3) vigorous-intensity continuous exercise (VICE, 85% HRR); and 4) high-intensity interval exercise (HIIE, 4 repetitions of a 30-s of "all out" cycling workout followed by a 4-min recovery). Blood samples were collected at 4 different time points (pre-exercise, immediately post-exercise, 30 min post-exercise, and 90 min post-exercise).

RESULTS

Serum FGF-21, FSTL-1, cathepsin B, and BDNF were higher in HIIE than in CTRL immediately post-exercise, and FSTL-1, cathepsin B, and BDNF were higher in HIIE than in MICE immediately post-exercise (P < 0.05). The AUC for FGF-21, FSTL-1, and BDNF was higher in HIIE than in CTRL, and the AUC for FGF-21 and BDNF was higher in HIIE than in MICE (P < 0.05). Furthermore, the change in blood lactate was positively correlated with the changes in all exerkines.

CONCLUSIONS

This study demonstrates that acute HIIE effectively increases serum FGF-21, FSTL-1, cathepsin B, and BDNF compared to MICE. Therefore, the secretion of exerkines, including FGF-21, FSTL-1, cathepsin B, and BDNF may be exercise intensity-dependent.

What is the optimal type and dose of physical activity for colorectal cancer prevention?

Epidemiological evidence shows that higher levels of physical activity reduce the relative risk of colon cancer by up to 20%. To design optimal physical activity interventions for primary prevention, it is important to understand how the specific characteristics of physical activity (type, intensity, overall volume) influence the magnitude of colon cancer risk reduction. Improving our understanding of the underlying biological mechanisms will also help to manipulate physical activity characteristics to precisely target mechanisms of action and identify populations most likely to benefit. This review synthesizes the best available evidence to explore how the type and dose of physical activity moderate the protective effect of physical activity on colon cancer.

The effect of exercise on cytokine concentration in equine autologous conditioned serum

BACKGROUND

Autologous conditioned serum (ACS) is a commonly administered intra-articular treatment for the management of osteoarthritis in athletic horses.

OBJECTIVES

To investigate the influence of exercise on the concentration of cytokines in a non-commercial method of ACS production.

STUDY DESIGN

Non-randomised cross over design.

METHODS

Whole blood was obtained from eight healthy Standardbred horses immediately prior to, 1 h and 24 h following a single bout of exhaustive exercise. Blood was processed using a non-commercial method of ACS production. Fluorescent microsphere immunoassay (FMIA) analysis was performed to quantify Interleukin 1 receptor antagonist (IL-1Ra), Interleukin-10 (IL-10), Interleukin 1β (IL-1β) and tumour necrosis factor α (TNF-α) concentrations at each time point. Mixed effect repeated measures analysis of variance (ANOVA) was used to compare the pre-exercise and post-exercise cytokine concentrations. Significance was set at P < 0.05.

RESULTS

A reduced concentration of IL-1Ra (median 584.4, IQR 81.9-5098 pg/ml, p = 0.004) and an increased concentration of TNF-α (11.92, 9.28-39.75 pg/ml, P = .05) at 1 h post-exercise were observed when compared with baseline values (IL-Ra 7349, 1272-10 760 pg/ml; TNF TNF-α 11.16, 8.36-32.74 pg/ml). No difference in cytokine concentrations of IL-10 or IL-1β were found between any of the time points.

MAIN LIMITATIONS

The large biological variability and small sample size represents limitations of this study.

CONCLUSIONS

These results suggest that a single bout of intense exercise can reduce the concentration of the anti-inflammatory cytokine IL-1Ra and increase the concentration of the pro-inflammatory cytokine TNF-α, reducing the 'anti-inflammatory' cytokine composition of ACS. Our findings suggest that collection of blood for ACS production should be performed no sooner than 24 h following a single episode of intense exercise.

Effects of Different Hydration Strategies in Young Men during Prolonged Exercise at Elevated Ambient Temperatures on Pro-Oxidative and Antioxidant Status Markers, Muscle Damage, and Inflammatory Status

Physical exercise is associated with an increase in the speed of metabolic processes to supply energy to working muscles and endogenous heat production. Intense sweating caused by the work performed at high ambient temperatures is associated with a significant loss of water and electrolytes, leading to dehydration. This study aimed to examine the effectiveness of different hydration strategies in young men during prolonged exercise at elevated ambient temperatures on levels of pro-oxidative and antioxidant status, oxidative status markers (TAC/TOC), muscle cell damage (Mb, LDH), and inflammatory status (WBC, CRP, IL-1β). The study was conducted on a group of 12 healthy men with average levels of aerobic capacity. The intervention consisted of using various hydration strategies: no hydration; water; and isotonic drinks. The examination was di-vided into two main stages. The first stage was a preliminary study that included medical exami-nations, measurements of somatic indices, and exercise tests. The exercise test was performed on a cycle ergometers. Their results were used to determine individual relative loads for the main part of the experiment. In the second stage, the main study was conducted, involving three series of weekly experimental tests using a cross-over design. The change in plasma volume (∆PV) measured im-mediately and one hour after the exercise test was significantly dependent on the hydration strategy (p = 0.003 and p = 0.002, respectively). The mean values of oxidative status did not differ signifi-cantly between the hydration strategy used and the sequence in which the test was performed. Using isotonic drinks, due to the more efficient restoration of the body’s water and electrolyte balance compared to water or no hydration, most effectively protects muscle cells from the negative effects of exercise, leading to heat stress of exogenous and endogenous origin.

Acute physiological outcomes of high-intensity functional training: a scoping review

Background

Systematic reviews and meta-analyses related to high-intensity functional training (HIFT) have been conducted. However, due to a restricted pool of available research, these investigations are often limited in scope. As such, a scoping review investigating the present literature surrounding the acute physiological response to HIFT-based exercise was chosen as a more appropriate structured review.

Methodology

A scoping review was conducted following Arksey and O'Malley's framework. Three large scale databases were searched to reveal any article pertaining to HIFT and related exercise terminology.

Results

A total of 2,241 articles were found during the initial search. Following this, titles, then abstracts, and full-texts were reviewed to determine inclusion eligibility. A total of 60 articles which investigated a combined total of 35 unique HIFT workouts were included within this review.

Conclusions

A variety of physiological parameters and HIFT workouts have been examined. Markers of intensity (e.g., blood lactate concentrations, heart rate) have been most consistently assessed across all studies, and these support the idea that HIFT workouts are typically performed at high-intensity. In contrast, the inclusion of most other measures (e.g., hormonal, markers of inflammation and damage, energy expenditure, performance) has been inconsistent and has thus, limited the possibility for making generalized conclusions. Differences in study methodologies have further impacted conclusions, as different studies have varied in sample population characteristics, workouts assessed, and time points. Though it may be impossible to comprehensively research all possible HIFT workouts, consistent adoption of population definitions and workload quantification may overcome this challenge and assist with future comparisons.

Acute Physiological Effects of Continuous Versus Intermittent Walking During Golf in Individuals With Knee Osteoarthritis: A Pilot Study

OBJECTIVE

The aim of the study was to compare the acute effects of walking the golf course versus using a golf cart during a round of golf on biological markers of joint disease, joint pain, and cardiovascular parameters in individuals with knee osteoarthritis.

METHODS

Participants with knee OA (n = 10) older than 50 yrs were recruited for this crossover designed study in which they completed two 18-hole rounds of golf: (1) walking the course and (2) using a golf cart. Five control participants (n = 5) performed the walking condition only. Step count, heart rate, rating of perceived exertion and pain using the Numeric Pain Rating Scale were measured during the round. Serum was collected at baseline, 9th hole (halfway), and 18th hole (completion) and tested for biomarkers associated with tissue turnover (cartilage oligomeric matrix protein), inflammation (tumor necrosis factor α, interleukin 1β, interleukin 6), and degradative enzyme production (matrix metalloproteinase 3, matrix metalloproteinase 13).

RESULTS

In knee OA participants, walking the course was associated with significantly higher step count and duration of moderate/vigorous physical activity (72.2% vs. 32.6% of the round) but did lead to a significant increase in knee joint pain (P < 0.05). Both conditions caused cartilage oligomeric matrix protein and matrix metalloproteinase 13 concentration increases from baseline to completion (P < 0.05), but inflammatory markers (tumor necrosis factor α, interleukin 6, and interleukin 1β, P < 0.05) only increased when walking the course. Biomarker concentrations did not increase in control participants.

CONCLUSIONS

Walking the course optimizes the duration of moderate/vigorous activity during a round of golf, but the golf cart is a beneficial option in those with exacerbated joint pain and inflammation that would otherwise limit participation.

Exercise training modulates adipokine dysregulations in metabolic syndrome

Metabolic syndrome (MetS) is a cluster of risk factors for various metabolic diseases, and it is characterized by central obesity, dyslipidemia, hypertension, and insulin resistance. The core component for MetS is adipose tissue, which releases adipokines and influences physical health. Adipokines consist of pro and anti-inflammatory cytokines and contribute to various physiological functions. Generally, a sedentary lifestyle promotes fat accumulation and secretion of pro-inflammatory adipokines. However, regular exercise has been known to exert various beneficial effects on metabolic and cognitive disorders. Although the mechanisms underlying exercise beneficial effects in MetS are not fully understood, changes in energy expenditure, fat accumulation, circulatory level of myokines, and adipokines might be involved. This review article focuses on some of the selected adipokines in MetS, and their responses to exercise training considering possible mechanisms.

Acute Effects of Strength and Endurance Training on Bone Turnover Markers in Young Adults and Elderly Men

CONTEXT

Exercise is recognized as an important strategy to prevent bone loss, but its acute effects on bone turnover markers (BTMs) and related markers remain uncertain.

OBJECTIVE

To assess the acute effects of two different exercise modes on BTMs and related markers in young adults of both sexes and elderly men.

DESIGN SETTING PARTICIPANTS

This was a three-group crossover within-subjects design study with a total of 53 participants-19 young women (aged 22-30), 20 young men (aged 21-30 years), and 14 elderly men (aged 63-74 years)-performing two different exercise sessions [strength training (ST) and high-intensity interval training (HIIT)] separated by 2 weeks, in a supervised laboratory setting.

MAIN OUTCOME MEASURES

Plasma volume-corrected serum measurements of the BTMs C-terminal telopeptide of type 1 collagen (CTX-I) and procollagen of type 1 N-terminal propeptide (P1NP), total osteocalcin (OC), sclerostin, and lipocalin-2 (LCN2) at baseline, immediately after, and 3 and 24 h after each of the two exercise modes were performed.

RESULTS AND CONCLUSION

Analyses revealed sex- and age-dependent differences in BTMs and related bone markers at baseline and time-, sex-, and age-dependent differences in response to exercise. No differences between exercise modes were observed for BTM response except for sclerostin in young men and LCN2 in elderly men. An acute, transient, and uniform increase in P1NP/CTX-1 ratio was found in young participants, demonstrating that beneficial skeletal effects on bone metabolism can be attained through both aerobic endurance and resistance exercise, although this effect seems to be attenuated with age. The acute effects of exercise on bone-related biomarkers were generally blunted after 24 h, suggesting that persistent alterations following prolonged exercise interventions should be assessed at later time points.

High intensity muscle stimulation activates a systemic Nrf2-mediated redox stress response

High intensity exercise is a popular mode of exercise to elicit similar or greater adaptive responses compared to traditional moderate intensity continuous exercise. However, the molecular mechanisms underlying these adaptive responses are still unclear. The purpose of this pilot study was to compare high and low intensity contractile stimulus on the Nrf2-mediated redox stress response in mouse skeletal muscle. An intra-animal design was used to control for variations in individual responses to muscle stimulation by comparing a stimulated limb (STIM) to the contralateral unstimulated control limb (CON). High Intensity (HI - 100Hz), Low Intensity (LI - 50Hz), and Naïve Control (NC - Mock stimulation vs CON) groups were used to compare these effects on Nrf2-ARE binding, Keap1 protein, and downstream gene and protein expression of Nrf2 target genes. Muscle stimulation significantly increased Nrf2-ARE binding in LI-STIM compared to LI-CON (p = 0.0098), while Nrf2-ARE binding was elevated in both HI-CON and HI-STIM compared to NC (p = 0.0007). The Nrf2-ARE results were mirrored in the downregulation of Keap1, where Keap1 expression in HI-CON and HI-STIM were both significantly lower than NC (p = 0.008) and decreased in LI-STIM compared to LI-CON (p = 0.015). In addition, stimulation increased NQO1 protein compared to contralateral control regardless of stimulation intensity (p = 0.019), and HO1 protein was significantly higher in high intensity compared to the Naïve control group (p = 0.002). Taken together, these data suggest a systemic redox signaling exerkine is activating Nrf2-ARE binding and is intensity gated, where Nrf2-ARE activation in contralateral control limbs were only seen in the HI group. Other research in exercise induced Nrf2 signaling support the general finding that Nrf2 is activated in peripheral tissues in response to exercise, however the specific exerkine responsible for the systemic signaling effects is not known. Future work should aim to delineate these redox sensitive systemic signaling mechanisms.

Age and Sport Intensity-Dependent Changes in Cytokines and Telomere Length in Elite Athletes

Exercise-associated immune response plays a crucial role in the aging process. The aim of this study is to investigate the effect of sport intensity on cytokine levels, oxidative stress markers and telomere length in aging elite athletes. In this study, 80 blood samples from consenting elite athletes were collected for anti-doping analysis at an anti-doping laboratory in Italy (FMSI). Participants were divided into three groups according to their sport intensity: low-intensity skills and power sports (LI, n = 18); moderate-intensity mixed soccer players (MI, n = 31); and high-intensity endurance sports (HI, n = 31). Participants were also divided into two age groups: less than 25 (n = 45) and above 25 years old (n = 35). Serum levels of 10 pro and anti-inflammatory cytokines and two antioxidant enzymes were compared in age and sport intensity groups and telomere lengths were measured in their respective blood samples. Tumor necrosis factor-alpha (TNF-α) was the only cytokine showing significantly higher concentration in older athletes, regardless of sport intensity. Interleukin (IL)-10 increased significantly in HI regardless of age group, whereas IL-6 concentration was higher in the older HI athletes. IL-8 showed a significant interaction with sport intensity in different age groups. Overall, significant positive correlations among levels of IL-6, IL-10, IL-8 and TNF-α were identified. The antioxidant catalase activity was positively correlated with levels of TNF-α. Telomere length increased significantly with sport intensity, especially in the younger group. HI had longer telomeres and higher levels of pro- and anti-inflammatory cytokines, suggesting less aging in HI compared to low and moderate counterparts in association with heightened immune response. Investigation of the functional significance of these associations on the health and performance of elite athletes is warranted.

Endocannabinoids and aging-Inflammation, neuroplasticity, mood and pain

Aging is associated with changes in hormones, slowing of metabolism, diminished physiological processes, chronic inflammation and high exposure to oxidative stress factors, generally described as the biological cost of living. Lifestyle interventions of diet and exercise can improve the quality of life during aging and lower diet-related chronic disease. The endocannabinoid system (ECS) has important effects on systemic metabolism and physiological systems, including the central and peripheral nervous systems. Exercise can reduce the loss of muscle mass and improve strength, and increase the levels of endocannabinoids (eCB) in brain and blood. Although the ECS exerts controls on multiple systems throughout life it affords benefits to natural aging. The eCB are synthesized from polyunsaturated fatty acids (PUFA) and the primary ones are produced from arachidonic acid (n-6 PUFA) and others from the n-3 PUFA, namely eicosapentaenoic and docosahexaenoic acids. The eCB ligands bind to their receptors, CB1 and CB2, with effects on appetite stimulation, metabolism, immune functions, and brain physiology and neuroplasticity. Dietary families of PUFA are a primary factor that can influence the types and levels of eCB and as a consequence, the downstream actions when the ligands bind to their receptors. Furthermore, the association of eCB with the synthesis of oxylipins (OxL) is a connection between the physiological actions of eCB and the lipid derived immunological OxL mediators of inflammation. OxL are ubiquitous and influence neuroinflammation and inflammatory processes. The emerging actions of eCB on neuroplasticity, well-being and pain are important to aging. Herein, we present information about the ECS and its components, how exercise and diet affects specific eCB, their role in neuroplasticity, neuroinflammation, pain, mood, and relationship to OxL. Poor nutrition status and low nutrient intakes observed with many elderly are reasons to examine the role of dietary PUFA actions on the ECS to improve health.

Effect of a 4-week fish oil supplementation on neuromuscular performance after exhaustive exercise in young healthy men

Neuromuscular function is one of the important factors affecting athletic performance. Previous studies have shown that fish oil supplementation can improve performance. This study investigated the effect of fish oil on neuromuscular performance after exhausting exercise. Eighteen healthy men (mean ± standard deviation; age 26.9±2.6 years; weight 78.33±10.42 kg; height 175.8±4.9 cm; body fat percentage 18.40±5.46%) voluntarily participated and were randomly assigned to fish and corn oil groups in a double blind manner. Participants received 6 g/day of oil for 4 weeks, while maintaining baseline diet and training status during the study. Changes in maximal voluntary contraction (MVC) of the tibialis anterior muscle, neuromuscular propagation of tibialis anterior muscle (M-wave), corticospinal excitability (MEP: motor evoked potential), and the rate of perceived exertion (RPE) were evaluated before and after supplementation in response to a modified Bruce exhausting protocol. Group differences in changes in each variable following supplementation were assessed by two-way analysis of variances (ANOVA). Compared to corn oil, fish oil demonstrated less perceived exertion at the end of exhaustive exercise (F=9.72, P=0.001) after supplementation, and normalised MEP to M-wave showed a trend (F=3.83, P=0.071). However, M-wave peak to peak amplitudes changes were not significant between the groups (P>0.05). In addition, significant differences were observed between baseline MVC values of the group following supplementation. Thus, it seems that fish oil can improve corticospinal excitability, thereby improving neuromuscular function in exhausting activities. Therefore, fish oil supplementation may be recommended to increase performance in activities otherwise limited. However, the mechanism underlying this effect remains to be elucidated.

Characterization and Modulation of Systemic Inflammatory Response to Exhaustive Exercise in Relation to Oxidative Stress

Exhaustive exercise induces systemic inflammatory responses, which are associated with exercise-induced tissue/organ damage, but the sources and triggers are not fully understood. Herein, the basics of inflammatory mediator cytokines and research findings on the effects of exercise on systemic inflammation are introduced. Subsequently, the association between inflammatory responses and tissue damage is examined in exercised and overloaded skeletal muscle and other internal organs. Furthermore, an overview of the interactions between oxidative stress and inflammatory mediator cytokines is provided. Particularly, the transcriptional regulation of redox signaling and pro-inflammatory cytokines is described, as the activation of the master regulatory factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is involved directly or indirectly in controlling pro-inflammatory genes and antioxidant enzymes expression, whilst nuclear factor-kappa B (NF-κB) regulates the pro-inflammatory gene expression. Additionally, preventive countermeasures against the pathogenesis along with the possibility of interventions such as direct and indirect antioxidants and anti-inflammatory agents are described. The aim of this review is to give an overview of studies on the systematic inflammatory responses to exercise, including our own group as well as others. Moreover, the challenges and future directions in understanding the role of exercise and functional foods in relation to inflammation and oxidative stress are discussed.

Identification of Urinary Biomarkers for Exercise-Induced Immunosuppression by iTRAQ Proteomics

Purpose

To identify noninvasive immune biomarkers of exercise-induced immunosuppression using the iTRAQ proteomics technique.

Methods

Fifteen healthy males were recruited and subjected to a four-week incremental treadmill running training program. After each week of training, WBC counts and CD4⁺ and CD8⁺ lymphocytes were measured to monitor the immune function status. iTRAQ proteomics technology was used to identify differential proteins and their characteristics in urine.

Results

Our data showed that the WBC counts, CD4⁺ lymphocytes, and CD4⁺/CD8⁺ ratio decreased by more than 10% after four weeks of training, suggesting exercise-induced immunosuppression. A total of 1854 proteins were identified in urine during the incremental running using the iTRAQ technology. Compared with the urine before training, there were 89, 52, 77, and 148 proteins significantly upregulated and 66, 27, 68, and 114 proteins significantly downregulated after each week, respectively. Among them, four upregulated proteins, SEMG-1, PIP, PDGFRL, and NDPK, increased their abundance with the increased exercise intensity. Bioinformatics analysis indicates that these proteins are involved in stress response and immune function.

Conclusion

Four weeks of incremental treadmill running induced immunosuppression in healthy males. By using iTRAQ proteomics, four proteins in the urine, SEMG-1, PIP, PDGFRL, and NDPK, were found to increase incrementally with the increased exercise intensity, which have the potential to be used as noninvasive immune biomarkers of exercise-induced immunosuppression.

The acute effects of walking exercise intensity on systemic cytokines and oxidative stress

Purpose

Oxidative stress is associated with tissue cytokine secretion although the precise mechanism(s) underpinning this relationship during high intensity intermittent exercise remains unclear. This study investigates the acute response to a bout of high intensity intermittent walking (HIIW), compared to continuous moderate intensity walking (CMW), on various cytokines and biomarkers of oxidative stress.

Methods

Seventeen (n = 17) apparently healthy male participants (aged 22.6 ± 4.6 years; \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2} \max$$\end{document}V˙O2max: 53.7 ± 7.1 ml kg⁻¹ min⁻¹) undertook a randomised crossover study consisting of two exercise trials: (1) HIIW requiring 3 × 5 min bursts at 80% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2} \max$$\end{document}V˙O2max (each separated by 5 min of walking at 30% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2} \max$$\end{document}V˙O2max) and (2) CMW (60% \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{V}{\text{O}}_{2} \max$$\end{document}V˙O2max for 30 min). Each trial was separated by 7 days. Venous blood samples were obtained pre-exercise, post-exercise and at 2, 4, 24 and 48 h post-exercise for determination of systemic inflammation (IL-6 and TNF-α), lipid soluble antioxidants and oxidative stress (LOOH, H₂O₂ and the ascorbyl free radical).

Results

Both IL-6 and TNF-α increased immediately post exercise, regardless of intensity and remained elevated until at least 4 h (main effect for time; p < 0.05). While there was no change in either lipid peroxidation or free radical metabolism (Asc· and H₂O₂), α-tocopherol increased (pooled HIIW and CMW, p < 0.05), whereas lycopene decreased at 2 h post HIIW (p < 0.05).

Conclusion

Bouts of both HIIW and CMW promote cytokine secretion post exercise, and this seems to be independent of oxidative stress. Further investigation is required to assess how such changes may underpin some of the transient health benefits of exercise.

Acute Effects of Whole-Body Vibration on Inflammatory Markers in People with Chronic Obstructive Pulmonary Disease: A Pilot Study

Whole-body vibration (WBV) has gained prominence in the rehabilitation of individuals with chronic obstructive pulmonary disease (COPD) because it is a safe and low intensity exercise that promises beneficial effects on physical performance and quality of life. However, its effects on plasma cytokine levels in COPD are still unclear. The aim of the current study was to investigate the acute effects of WBV on inflammatory biomarkers in people with COPD. Twenty-six participants, COPD people (n=13) and healthy controls (n=13), were included. Both groups performed WBV at amplitude of 2 mm and frequency of vibration of 35 Hz, during six series of 30 seconds. They were assessed for lung function, body composition, 6-minute walking test (6MWT), handgrip strength test, plasma concentrations of interleukin (IL), IL-6, IL-8, and IL-10, and soluble tumor necrosis factor alpha (TNF-α) receptors (sTNFR-1 and sTNFR-2). People with COPD had moderate disease [forced expiratory volume in the first second (FEV1) = 58.1%], as well as a worse performance in the 6MWT. The plasma cytokine profile at rest showed that participants with COPD had higher levels of IL-8 and lower levels of IL-10. After one session of WBV, we found an increased plasma IL-10 level in the COPD group, with similar levels for healthy controls. One session of WBV modified the plasma IL-10 level. No effects were found on the other investigated cytokines.

Exercise-induced 'browning' of adipose tissues

Global rates of obesity continue to rise and are necessarily the consequence of a long-term imbalance between energy intake and energy expenditure. This is the result of an expansion of adipose tissue due to both the hypertrophy of existing adipocytes and hyperplasia of adipocyte pre-cursors. Exercise elicits numerous physiological benefits on adipose tissue, which are likely to contribute to the associated cardiometabolic benefits. More recently it has been demonstrated that exercise, through a range of mechanisms, induces a phenotypic switch in adipose tissue from energy storing white adipocytes to thermogenic beige adipocytes. This has generated the hypothesis that the process of adipocyte 'browning' may partially underlie the improved cardiometabolic health in physically active populations. Interestingly, 'browning' also occurs in response to various stressors and could represent an adaptive response. In the context of exercise, it is not clear whether the appearance of beige adipocytes is metabolically beneficial or whether they occur as a transient adaptive process to exercise-induced stresses. The present review discusses the various mechanisms (e.g. fatty acid oxidation during exercise, decreased thermal insulation, stressors and angiogenesis) by which the exercise-induced 'browning' process may occur.

Comparable Neutrophil Responses for Arm and Intensity-matched Leg Exercise

INTRODUCTION

Arm exercise is performed at lower absolute intensities than lower body exercise. This may impact on intensity-dependent neutrophil responses, and it is unknown whether individuals restricted to arm exercise experience the same changes in the neutrophil response as found for lower body exercise. Therefore, we aimed to investigate the importance of exercise modality and relative exercise intensity on the neutrophil response.

METHODS

Twelve moderately trained men performed three 45-min constant load exercise trials after determination of peak oxygen uptake for arm exercise (V˙O2peak arms) and cycling (V˙O2peak legs): 1) arm cranking exercise at 60% V˙O2peak arms, 2) moderate cycling at 60% V˙O2peak legs, and 3) easy cycling at 60% V˙O2peak arms.

RESULTS

Neutrophil numbers in the circulation increased for all exercise trials, but were significantly lower for easy cycling when compared with arm exercise (P = 0.009), mirroring the blunted increase in HR and epinephrine during easy cycling. For all trials, exercising HR explained some of the variation of the neutrophil number 2 h postexercise (R = 0.51-0.69), epinephrine explaining less of this variation (R = 0.21-0.34). The number of neutrophils expressing CXCR2 decreased in the recovery from exercise in all trials (P < 0.05).

CONCLUSIONS

Arm and leg exercise elicits the same neutrophil response when performed at the same relative intensity, implying that populations restricted to arm exercise might achieve a similar exercise induced neutrophil response as those performing lower body exercise. A likely explanation for this is the higher sympathetic activation and cardiac output for arm and relative intensity-matched leg exercise when compared with easy cycling, which is partly reflected in HR. This study further shows that the downregulation of CXCR2 may be implicated in exercise-induced neutrophilia.

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.

Potential involvement of lactate and interleukin-6 in the appetite-regulatory hormonal response to an acute exercise bout

This study examines the involvement of two potential mechanisms (lactate and IL-6) that may explain the intensity-dependent effects of acute exercise on appetite-related parameters. Our findings support a clear intensity-dependent paradigm for appetite-regulation following exercise, as highlighted by the change in acylated ghrelin and the suppression of appetite and energy intake after vigorous exercise (continuous and intermittent). Further, our findings extend previous work in animal/cell models by providing evidence for the potential role of lactate and IL-6 in mediating changes in appetite-related parameters following exercise in humans.

High-intensity exercise suppresses appetite partly through changes in peripheral appetite-regulating hormones. Lactate and IL-6 mediate the release of these hormones in animal/cell models and may provide a mechanistic link between exercise intensity and appetite regulation. The current study examined changes in appetite-regulating hormones, lactate, and IL-6 after different intensities of running. Eight males completed four experimental sessions: 1) moderate-intensity continuous training (MICT; 65% V̇o_2max); 2) vigorous-intensity continuous training (VICT; 85% V̇o_2max); 3) sprint interval training (SIT; repeated “all-out” sprints); and 4) Control (CTRL; no exercise). Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), total peptide YY (PYY), lactate, IL-6, and appetite perceptions were measured pre-, immediately postexercise, 30 min postexercise, and 90 min postexercise. Energy intake was recorded over 3 days. VICT and SIT suppressed ghrelin (P < 0.001), although SIT elicited a greater (P = 0.016 vs. MICT) and more prolonged (P < 0.001 vs. all sessions) response. GLP-1 increased immediately after MICT (P < 0.001) and 30 min after VICT (P < 0.001) and SIT (P < 0.002), while VICT elicited a greater postexercise increase in PYY vs. MICT (P = 0.027). Postexercise changes in blood lactate and IL-6 correlated with the area under the curve values for ghrelin (r = −0.60, P < 0.001) and GLP-1 (r = 0.42, P = 0.017), respectively. Appetite was suppressed after exercise (P < 0.001), although more so after VICT (P < 0.027) and SIT (P < 0.001) vs. MICT, and energy intake was reduced on the day after VICT (P < 0.017 vs. MICT and CTRL) and SIT (P = 0.049 vs. MICT). These findings support an intensity-dependent paradigm for appetite regulation following exercise and highlight the potential involvement of lactate and IL-6.

NEW & NOTEWORTHY This study examines the involvement of two potential mechanisms (lactate and IL-6) that may explain the intensity-dependent effects of acute exercise on appetite-related parameters. Our findings support a clear intensity-dependent paradigm for appetite regulation following exercise, as highlighted by the change in acylated ghrelin and the suppression of appetite and energy intake after vigorous exercise (continuous and intermittent). Further, our findings extend previous work in animal/cell models by providing evidence for the potential role of lactate and IL-6 in mediating changes in appetite-related parameters following exercise in humans.

IL-6, Antioxidant Capacity and Muscle Damage Markers Following High-Intensity Interval Training Protocols

The aim of this study was to investigate changes of interleukin-6 (IL-6), total antioxidant capacity (TAC) and muscle damage markers (creatine kinase (CK), myoglobin and lactate dehydrogenase (LDH)) in response to three different high-intensity interval training (HIIT) protocols of identical external work. Twelve moderately-trained males participated in the three HIIT trials which consisted of a warm-up, followed by 12 min of 15 s, 30 s or 60 s HIIT sequences with the work/rest ratio 1. The biochemical markers of inflammation, oxidative stress and muscle damage were analysed POST, 3 h and 24 h after the exercise. All HIIT protocols caused an immediate increase in IL-6, TAC, CK, myoglobin and LDH. The most pronounced between-trials differences were found for the POST-exercise changes in IL-6 (Effect size ± 90% confidence interval: 1.51 ± 0.63, 0.84 ± 0.34 and 1.80 ± 0.60 for the 15s/15s, 30s/30s and 60s/60s protocol, respectively) and myoglobin (1.11 ± 0.29, 0.45 ± 0.48 and 1.09 ± 0.22 for the 15s/15s, 30s/30s and 60s/60s protocol, respectively). There were no substantial between-trial differences in other biochemical variables. In conclusion, the 15s/15s and 60s/60s protocols might be preferred to the 30s/30s protocols in order to maximize the training stimulus.

Impact of physical activity and mechanical loading on biomarkers typically used in osteoarthritis assessment: current concepts and knowledge gaps

There is an ongoing need to develop prognostic and diagnostic biomarkers for osteoarthritis (OA). Understanding how biomarkers change in response to physical activity may be vital for understanding if a patient has a joint that is failing to adapt to a given loading stimulus. The purpose of this review is to describe how biomarker changes after joint loading may help detect early OA and determine prognosis. This may help to inform and more specifically target interventions and clinical trials. We conducted a critical review of the relevant literature that was published to January 2016. There is extensive OA biomarker research, specifically basal biomarker concentrations; however, there is limited research surrounding biomarker response to load. Some of this limited research includes the response of minimal biomarkers reflecting bone, synovium, inflammatory, and cartilage responses to load. Biomarker changes occur in bone and cartilage in response to a variety of activities and are influenced by variables such as body weight, load, vibration, and activity time. Biomarker responses to loading tasks may serve as a measure of overall joint health and be predictive of structural changes. Biomarkers adapt to training over time, and this may indicate a need for a gradual return to physical activity after an injury to allow time for joint tissues to adapt to load. Biomarker responses to physical activity may be monitored to determine appropriate loading levels and safety for return to activity.

Endothelial and inflammatory responses to acute exercise in perimenopausal and late postmenopausal women

Endothelial dysfunction and inflammation are characteristics of subclinical atherosclerosis and may increase through progressive menopausal stages. Evaluating endothelial responses to acute exercise can reveal underlying dysfunction not apparent in resting conditions. The purpose of this study was to investigate markers of endothelial function and inflammation before and after acute exercise in healthy low-active perimenopausal (PERI) and late postmenopausal (POST) women. Flow-mediated dilation (FMD), CD31⁺/CD42b^- and CD62E⁺ endothelial microparticles (EMPs), and the circulating inflammatory factors monocyte chemoattractant protein 1 (MCP-1), interleukin 8 (IL-8), and tumor necrosis factor-α (TNF-α) were measured before and 30 min after acute exercise. Before exercise, FMD was not different between groups (PERI: 6.4 ± 0.9% vs. POST: 6.5 ± 0.8%, P = 0.97); however, after acute exercise PERI tended to improve FMD (8.5 ± 0.9%, P = 0.09), whereas POST did not (6.2 ± 0.8%, P = 0.77). Independent of exercise, we observed transient endothelial dysfunction in POST with repeated FMD measures. There was a group × exercise interaction for CD31⁺/CD42b^- EMPs (P = 0.04), where CD31⁺/CD42b^- EMPs were similar before exercise (PERI: 57.0 ± 6.7 EMPs/μl vs. POST: 58.5 ± 5.3 EMPs/μl, P = 0.86) but were higher in POST following exercise (PERI: 48.2 ± 6.7 EMPs/μl vs. POST: 69.4 ± 5.3 EMPs/μl, P = 0.023). CD62E⁺ EMPs were lower in PERI compared with POST before exercise (P < 0.001) and increased in PERI (P = 0.04) but did not change in POST (P = 0.68) in response to acute exercise. After acute exercise, MCP-1 (P = 0.055), TNF-α (P = 0.02), and IL-8 (P < 0.001) were lower in PERI but only IL-8 decreased in POST (P < 0.001). Overall, these data suggest that perimenopausal and late postmenopausal women display different endothelial and inflammatory responses to acute exercise.

Cannabis and Exercise Science: A Commentary on Existing Studies and Suggestions for Future Directions

Policies regarding cannabis use are rapidly changing, yet public officials have limited access to scientific information that might inform the creation of these policies. One important area in which to begin investigations is the link between recreational cannabis use and health, specifically exercise. There are common anecdotal reports that cannabis decreases motivation, including motivation to exercise. On the other hand, there are also anecdotal reports that cannabis is used prior to athletic activity. In fact, the World Anti-Doping Agency includes cannabis as a prohibited substance in sport, partly because it is believed that it may enhance sports performance. At the current time, there is limited scientific evidence to support either one of these opposing lay perspectives. Given recent political, cultural, and legal trends, and the growing acceptance of recreational cannabis use, it is important to develop a more nuanced understanding of the relationship between cannabis and exercise, specifically the potential effects of use on exercise performance, motivation, and recovery.

Interleukin-6 and associated cytokine responses to an acute bout of high-intensity interval exercise: the effect of exercise intensity and volume

Acute increases in interleukin (IL)-6 following prolonged exercise are associated with the induction of a transient anti-inflammatory state (e.g., increases in IL-10) that is partly responsible for the health benefits of regular exercise. The purposes of this study were to investigate the IL-6-related inflammatory response to high-intensity interval exercise (HIIE) and to determine the impact of exercise intensity and volume on this response. Ten participants (5 males and 5 females) completed 3 exercise bouts of contrasting intensity and volume (LOW, MOD, and HIGH). The HIGH protocol was based upon standard HIIE protocols, while the MOD and LOW protocols were designed to enable a comparison of exercise intensity and volume with a fixed duration. Inflammatory cytokine concentrations were measured in plasma (IL-6, IL-10) and also determined the level of gene expression (IL-6, IL-10, and IL-4R) in peripheral blood. The plasma IL-6 response to exercise (reported as fold changes) was significantly greater in HIGH (2.70 ± 1.51) than LOW (1.40 ± 0.32) (P = 0.04) and was also positively correlated to the mean exercise oxygen uptake (r = 0.54, P < 0.01). However, there was no change in anti-inflammatory IL-10 or IL-4R responses in plasma or at the level of gene expression. HIIE caused a significant increase in IL-6 and was greater than that seen in low-intensity exercise of the same duration. The increases in IL-6 were relatively small in magnitude, and appear to have been insufficient to induce the acute systemic anti-inflammatory effects, which are evident following longer duration exercise.

A Systematic Review of the Acute Effects of Exercise on Immune and Inflammatory Indices in Untrained Adults

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of global mortality. Although the incidence may be reduced with regular exercise, the health benefits of a single bout of exercise on selected CVD risk factors are not well understood. The primary objective of this review is to consider the transient effects of exercise on immune (neutrophil count) and inflammatory (interleukin-6 [IL-6], C-reactive protein [CRP]) markers in untrained adults.

METHODS

MEDLINE, EMBASE, CINAHL, Sports Discus and Cochrane were searched for relevant studies published from January 1946 to May 2013. Randomised controlled or crossover studies which measured any of these parameters in untrained but otherwise healthy participants in the 48 h following about of exercise, less than 1 h in duration were included.

RESULTS

Ten studies met the inclusion criteria. The results indicate a single bout of aerobic or resistance exercise of moderate to high intensity promotes an increase in IL-6 (145 %) and neutrophil counts (51 %). It appears that 30-60 min of moderate to high intensity exercise is necessary to elicit such changes although variables such as the mode, intensity and pattern of exercise also affect the response. The acute response of CRP within the included studies is equivocal.

CONCLUSIONS

Although responses to CRP are inconsistent, a single bout of exercise can increase the activity of both circulating IL-6 and neutrophil counts in untrained adults. These immune and inflammatory responses to a single bout of exercise may be linked to a range of health benefits.

Plasma cytokine and exertional responses in relation to exercise intensity and volume of exercising muscle mass during arm-crank ergometry

This original study investigated the effect of submaximal exercise intensity and volume of contracting muscle mass on plasma inflammation-mediating cytokine and perceived exertional responses to acute arm-crank ergometry (ACE). Twelve recreationally active but upper limb untrained males performed 30 min of (i) low-intensity (40% peak oxygen uptake) ACE (LOW); (ii) moderate-intensity (60% peak oxygen uptake) ACE (MOD); and (iii) concurrent low-intensity (40% peak oxygen uptake) ACE plus lower limb cycle ergometry to match total power output in MOD (HYB). Plasma concentrations of interleukin (IL)-6, IL-10, IL-1ra, adrenaline, and cortisol were determined at rest, immediately postexercise, and 1 h and 2 h postexercise. Heart rate (HR) and differentiated ratings of perceived exertion (RPE) were also recorded. Plasma IL-6 concentrations were elevated (p < 0.05) immediately postexercise and 1 h postexercise (∼ 2.5-fold) in all trials and 2 h postexercise in MOD (3-fold). Plasma IL-1ra concentrations were elevated (p < 0.05) 2 h postexercise in MOD only (2-fold). No plasma IL-10, cortisol, and adrenaline responses were observed. HR and differentiated RPE were significantly higher during MOD than HYB and LOW. Peripheral RPE were significantly higher than central and overall RPE in each trial. Thirty minutes of moderate intensity ACE initiated a plasma cytokine response associated with the protective effect of regular exercise against cardiovascular and metabolic disease risk. Further work is required to establish an optimal intensity and duration of upper limb exercise to maximise the anti-inflammatory potential whilst managing the risk of over-use injury.

Inflammation-mediating cytokine response to acute handcycling exercise with/without functional electrical stimulation-evoked lower-limb cycling

This feasibility study compared the plasma inflammation-mediating cytokine response to an acute bout of handcycling (HC) with and without the addition of functional electrical stimulation (FES)-evoked lower-limb cycling. On two separate occasions, five recreationally active, community-based participants with motor complete paraplegia (thoracic 5- 7) performed 30 min HC and hybrid exercise (HYB) at a fixed power output. Venous blood samples were collected at rest, immediately postexercise, 1 h postexercise (post+1) and 2 h postexercise (post+2). Plasma interleukin (IL)-6, IL-10, IL-1 receptor antagonist (IL-1ra), adrenaline, and cortisol concentrations were determined via enzyme-linked immunoassay. Plasma IL-6 concentrations were significantly (p < 0.04) elevated (~2.5-fold) at post+1 and post+2 in HYB only. A small (0.5-fold), nonsignificant (p > 0.05) increase in IL-6 was observed at post+1 in HC, with concentrations significantly higher in HYB at post+2 (p < 0.02). Plasma IL-1ra was unaffected in both trials. Although not reaching statistical significance (p = 0.15), a ~1-fold increase in IL-10 concentration was seen in HYB at post+2. In contrast, increases in adrenaline (p < 0.04) and cortisol (p = 0.08) were observed immediately postexercise in HC and HYB. Initial findings suggest paralyzed skeletal muscle releases IL-6 in response to FES-evoked contractions. HYB may provide a greater anti-inflammatory potential in individuals with a thoracic spinal cord injury compared with HC alone.

Physical activity and the endocannabinoid system: an overview

Recognized as a "disease modifier", physical activity (PA) is increasingly viewed as a more holistic, cost-saving method for prevention, treatment and management of human disease conditions. The traditional view that PA engages the monoaminergic and endorphinergic systems has been challenged by the discovery of the endocannabinoid system (ECS), composed of endogenous lipids, their target receptors, and metabolic enzymes. Indeed, direct and indirect evidence suggests that the ECS might mediate some of the PA-triggered effects throughout the body. Moreover, it is now emerging that PA itself is able to modulate ECS in different ways. Against this background, in the present review we shall discuss evidence of the cross-talk between PA and the ECS, ranging from brain to peripheral districts and highlighting how ECS must be tightly regulated during PA, in order to maintain its beneficial effects on cognition, mood, and nociception, while avoiding impaired energy metabolism, oxidative stress, and inflammatory processes.

The expression of cytokines and chemokines in the blood of patients with severe weight loss from anorexia nervosa: an exploratory study

Anorexia nervosa (AN) is a serious, potentially life-threatening disorder characterized by severe weight loss, dysregulated eating, and often excessive exercise. While psychiatric illnesses such as depression are associated with increased levels of pro-inflammatory mediators, evidence for such disturbances in patients with AN has been less clear. In an exploratory study of possible disturbances in immune responses in AN, we assayed a panel of cytokines and chemokines in the blood of patients undergoing inpatient treatment, testing the hypothesis that metabolic disturbances in this disease would lead to a pattern of immune disturbances distinct from that of other psychiatric diseases. For this purpose, we evaluated patients by the Beck Depression Inventory-II (BDI-II) and the Eating Disorders Examination-Questionnaire and assessed cytokines and chemokines by enzyme-linked immunosorbent assays. Patients reported a moderate level of depression (mean BDI-II = 22.6) but exhibited few immunologic abnormalities of the kind associated with major depressive disorder [e.g., increased interleukin (IL)-6]; RANTES showed the most frequent elevations and was increased in 4 of the patients studied. Together, these findings suggest that features of AN such as loss of adipose tissue and excessive exercise may attenuate cytokine production and thus modulate the experience of illness that impacts on core features of disease.

Influence of oxidative stress, diaphragm fatigue, and inspiratory muscle training on the plasma cytokine response to maximum sustainable voluntary ventilation

The influence of oxidative stress, diaphragm fatigue, and inspiratory muscle training (IMT) on the cytokine response to maximum sustainable voluntary ventilation (MSVV) is unknown. Twelve healthy males were divided equally into an IMT or placebo (PLA) group, and before and after a 6-wk intervention they undertook, on separate days, 1 h of ( 1) passive rest and ( 2) MSVV, whereby participants undertook volitional hyperpnea at rest that mimicked the breathing and respiratory muscle recruitment patterns commensurate with heavy cycling exercise. Plasma cytokines remained unchanged during passive rest. There was a main effect of time ( P < 0.01) for plasma interleukin-1β (IL-1β) and interleukin-6 (IL-6) concentrations and a strong trend ( P = 0.067) for plasma interleukin-1 receptor antagonist concentration during MSVV. Plasma IL-6 concentration was reduced after IMT by 27 ± 18% (main effect of intervention, P = 0.029), whereas there was no change after PLA ( P = 0.753). There was no increase in a systemic marker of oxidative stress [DNA damage in peripheral blood mononuclear cells (PBMC)], and diaphragm fatigue was not related to the increases in plasma IL-1β and IL-6 concentrations. A dose-response relationship was observed between respiratory muscle work and minute ventilation and increases in plasma IL-6 concentration. In conclusion, increases in plasma IL-1β and IL-6 concentrations during MSVV were not due to diaphragm fatigue or DNA damage in PBMC. Increases in plasma IL-6 concentration during MSVV are attenuated following IMT, and the plasma IL-6 response is dependent upon the level of respiratory muscle work and minute ventilation.

Circulating angiogenic and inflammatory cytokine responses to acute aerobic exercise in trained and sedentary young men

PURPOSE

Endurance exercise training can ameliorate many cardiovascular and metabolic disorders and attenuate responses to inflammatory stimuli. The purpose of this study was to determine whether the angiogenic and pro-inflammatory cytokine response to acute endurance exercise differs between endurance-trained and sedentary young men.

METHODS

Ten endurance-trained and ten sedentary healthy young men performed 30 min of treadmill running at 75 % VO2max with blood sampling before and after exercise. Plasma concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-8, IL-6, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), placental growth factor (PlGF), and soluble VEGF receptor-1 (sFlt-1) were measured by multiplex ELISA.

RESULTS

Acute exercise increased IL-6 by 165 % (P < 0.05), IL-8 by 32 % (P < 0.05), PlGF by ~16 % (P < 0.05), sFlt-1 by 36 % (P < 0.001), and tended to increase bFGF by ~25 % (P = 0.06) in main effects analyses. TNF-α and VEGF did not change significantly with exercise in either group. Contrary to our hypothesis, there were no significant differences in TNF-α, IL-6, VEGF, bFGF, PlGF, or sFlt-1 between groups before or after acute exercise; however, there was a tendency for IL-8 concentrations to be higher in endurance-trained subjects compared to sedentary subjects (P = 0.06).

CONCLUSIONS

These results indicate that 30 min of treadmill running at 75 % VO2max produces a systemic angiogenic and inflammatory reaction, but endurance exercise training does not appear to significantly alter these responses in healthy young men.

Impact of exercise and metabolic disorders on heat shock proteins and vascular inflammation

Heat shock proteins (Hsp) play critical roles in the body's self-defense under a variety of stresses, including heat shock, oxidative stress, radiation, and wounds, through the regulation of folding and functions of relevant cellular proteins. Exercise increases the levels of Hsp through elevated temperature, hormones, calcium fluxes, reactive oxygen species (ROS), or mechanical deformation of tissues. Isotonic contractions and endurance- type activities tend to increase Hsp60 and Hsp70. Eccentric muscle contractions lead to phosphorylation and translocation of Hsp25/27. Exercise-induced transient increases of Hsp inhibit the generation of inflammatory mediators and vascular inflammation. Metabolic disorders (hyperglycemia and dyslipidemia) are associated with type 1 diabetes (an autoimmune disease), type 2 diabetes (the common type of diabetes usually associated with obesity), and atherosclerotic cardiovascular disease. Metabolic disorders activate HSF/Hsp pathway, which was associated with oxidative stress, increased generation of inflammatory mediators, vascular inflammation, and cell injury. Knock down of heat shock factor-1 (HSF1) reduced the activation of key inflammatory mediators in vascular cells. Accumulating lines of evidence suggest that the activation of HSF/Hsp induced by exercise or metabolic disorders may play a dual role in inflammation. The benefits of exercise on inflammation and metabolism depend on the type, intensity, and duration of physical activity.

Exercise-induced immunodepression in endurance athletes and nutritional intervention with carbohydrate, protein and fat-what is possible, what is not?

Heavily exercising endurance athletes experience extreme physiologic stress, which is associated with temporary immunodepression and higher risk of infection, particularly upper respiratory tract infections (URTI). The aim of this review is to provide a critical up-to-date review of existing evidence on the immunomodulatory potential of selected macronutrients and to evaluate their efficacy. The results of 66 placebo-controlled and/or crossover trials were compared and analysed. Among macronutrients, the most effective approach to maintain immune function in athletes is to consume ≥6% carbohydrate during prolonged exercise. Because inadequate nutrition affects almost all aspects of the immune system, a well-balanced diet is also important. Evidence of beneficial effects from other macronutrients is scarce and results are often inconsistent. Using a single nutrient may not be as effective as a mixture of several nutritional supplements. Due to limited research evidence, with the exception of carbohydrate, no explicit recommendations to reduce post-exercise URTI symptoms with single macronutrients can be derived.