Cytokine response to strenuous exercise in athletes and non-athletes--an adaptive response

Monitoring the physiological inflammatory alertness in horse after road transport

The aim of this study was to assess the changes of pro-inflammatory interleukins in 10 horses subjected to road transport practices (distance of 150 km) from the training site (Messina, Sicily) to the competition centre in Syracuse (Sicily). Blood sampling and interleukins analysis were performed during a round trip transportation (transport 1 and transport 2). In particular, blood samples were collected before the transport took place (Pre), five minutes later (Post) and one hour later (Post 1 h), for each transport, in order to assess the serum concentration of IL-1α, IL-1β, IL-2 and IL-6. The results showed that the serum concentration of IL-1α decreased at Post and Post 1 h compared to the values obtained at rest condition (P < 0.05). The other interleukins analysed (i.e. IL-1β, IL-2 and IL-6) showed increased levels at Post than Rest and Post 1 h in transport 1 (P < 0.05). In transport 2 the analysed parameters showed no change throughout the analysed time points (P > 0.05); however, higher levels of IL-1α at Pre and higher IL-1β, IL-2 and IL-6 values at Post were found in transport 1 than transport 2 (P < 0.05). The increase in pro-inflammatory cytokines after transport 1 suggests the triggering of the inflammatory event and this may show that, although horses are animals accustomed to transport, this is a stressful event that could activate the well-orchestrated inflammation cascade, albeit physiological and temporary, as highlighted by the lower serum concentrations of the investigated interleukins found in transport 1 than transport 2 and by the lack of significant differences in the serum concentrations of the investigated interleukins among the time points of transport 2. It must be taken into account that enrolled animals are well-trained and healthy athletic horses participating to a jumper competition, thus, such inflammation did not occur thanks to a good balance between pro-inflammatory and anti-inflammatory cytokines which allowed a prompt restoration of homeostasis eventually impaired by the stressful event.

Effect of 2 weeks rest-pause on oxidative stress and inflammation in female basketball players

Intense exercise leads to increased production of free radicals, resulting in an inflammatory response in athletes. For this reason, it was decided to investigate whether a single intensive exercise until exhaustion applied after a 2-week rest period would result in a violation of the pro-oxidant-antioxidant balance. Twenty-seven trained female basketball players (age: 16.55 ± 0.96 years, body mass: 66.40 ± 13.68 kg, height: 173.45 ± 5.14 cm) were enrolled to the study following the application of inclusion and exclusion criteria. Study was conducted at the end of the competitive training phase. Participants underwent incremental treadmill exercise, with blood samples collected before the test, immediately post-exercise, and after a 3-h restitution period. Total antioxidant capacity (TAC) levels increased significantly after exercise and remained unchanged after 3 h. Concentration of interleukin-10 (IL-10) and creatine kinase (CK) significantly increased after exercise and then decreased. Concentration of interleukin-2 (IL-2) was significantly reduced immediately and 3 h after exercise, while interleukin-13 (IL-13), interleukin-1α (IL-1α), and tryptophan (TRP) decreased 3 h after exercise. No significant changes were observed in other biochemical parameters. Obtained results show an increased antioxidant capacity which reduced oxidative stress and inflammation in response to intense exercise indicating that rested athletes have a high adaptation and elevated tolerance to effort.

Demystifying roles of exercise in immune response regulation against acute respiratory infections: A narrative review

The benefits of physical activity and exercise, especially those classified as moderate-to-vigorous activity (MVPA), have been well-established in preventing non-communicable diseases and mental health problems in healthy adults. However, the relationship between physical activity and exercise and the prevention and management of acute respiratory infection (ARI), a global high-burden disease, has been inconclusive. There have been debates and disagreements among scientific publications regarding the relationship between exercise and immune response against the causative agents of ARI. This narrative review aims to explore the theory that sufficiently explains the correlation between exercise, immune response, and ARI. The potential root causes of discrepancies come from research associated with the "open window" hypothesis. The studies have several limitations, and future improvements to address them are urgently needed in the study design, data collection, exercise intervention, subject recruitment, biomarkers for infection and inflammation, nutritional and metabolism status, and in addressing confounding variables. In conclusion, data support the clinical advantages of exercise have a regulatory contribution toward improving the immune response, which in turn potentially protects humans fromARI. However, the hypothesis related to its negative effect must be adopted cautiously.

Impacts of different triathlon races on systemic cytokine profile and metabolic parameters in healthy individuals: a systematic review

The present systematic review aimed to discuss the impacts of different triathlon protocols on the level of pro and anti-inflammatory cytokines, as well as biomarkers related to the performance of healthy individuals. Four databases [PubMed (28 articles), Scopus (24 articles), Science Direct (200 articles), and SPORT Discus (1101 articles) were assessed. The eligibility criteria were applied, and the selected articles were used in the peer review, independently, as they were identified by March 2022. Of the 1359 articles found, 10 were included in this systematic review. Despite the difference in triathlon protocols, it was observed an increase in pro and anti-inflammatory cytokines including IL-4 and IL-10, and chemokines, such as IL-8 and MCP-1. Moreover, the anti-inflammatory serum levels increase after triathlon. Overall, the studies also reported enhancement in the serum levels of cortisol, creatine kinase, C reactive protein, Endothelial Growth Factor, Vascular Endothelial Growth Factor, Myostatin, Lactate dehydrogenase, free fatty acids, and lactate dehydrogenase in triathlon athletes. This systematic review indicates that different triathlon race promotes an acute elevation of circulating cytokines and chemokines levels which return to standard levels after triathlon races. The findings of this systematic review demonstrate that the modulation of inflammatory parameters may be associated with an increase in metabolic indicators (CK, Cortisol, and LDH) after the end of different types of triathlon races.

Cytokines as Biomarkers for Evaluating Physical Exercise in Trained and Non-Trained Individuals: A Narrative Review

Physical activity and exercise training have numerous health benefits, including the prevention and management of chronic diseases, improvement of cardiovascular health, and enhancement of mental well-being. However, the effectiveness of training programs can vary widely among individuals due to various factors, such as genetics, lifestyle, and environment. Thus, identifying reliable biomarkers to evaluate physical training effectiveness and personalize training programs is crucial. Cytokines are signaling molecules produced by immune cells that play a vital role in inflammation and tissue repair. In recent years, there has been increasing interest in the potential use of cytokines as biomarkers for evaluating training effectiveness. This review article aims to provide an overview of cytokines, their potential as biomarkers, methods for measuring cytokine levels, and factors that can affect cytokine levels. The article also discusses the potential benefits of using cytokines as biomarkers, such as monitoring muscle damage and inflammation, and the potential for personalized training programs based on cytokine responses. We believe that the use of cytokines as biomarkers holds great promise for optimizing training programs and improving overall health outcomes.

Endocrine responses of the stress system to different types of exercise

Physical activity is an important part of human lifestyle although a large percentage of the population remains sedentary. Exercise represents a stress paradigm in which many regulatory endocrine systems are involved to achieve homeostasis. These endocrine adaptive responses may be either beneficial or harmful in case they exceed a certain threshold. The aim of this review is to examine the adaptive endocrine responses of hypothalamic-pituitary-adrenal axis (HPA), catecholamines, cytokines, growth hormone (GH) and prolactin (PRL) to a single bout or regular exercise of three distinct types of exercise, namely endurance, high-intensity interval (HIIE) and resistance exercise. In summary, a single bout of endurance exercise induces cortisol increase, while regular endurance exercise-induced activation of the HPA axis results to relatively increased basal cortisolemia; single bout or regular exercise induce similar GH peak responses; regular HIIE training lowers basal cortisol concentrations, while catecholamine response is reduced in regular HIIE compared with a single bout of HIIE. HPA axis response to resistance exercise depends on the intensity and volume of the exercise. A single bout of resistance exercise is characterized by mild HPA axis stimulation while regular resistance training in elderly results in attenuated inflammatory response and decreased resting cytokine concentrations. In conclusion, it is important to consider which type of exercise and what threshold is suitable for different target groups of exercising people. This approach intends to suggest types of exercise appropriate for different target groups in health and disease and subsequently to introduce them as medical prescription models.

High-intensity circuit training change serum myostatin but not myogenin in adolescents' soccer players: a quasi-experimental study

BACKGROUND

Skeletal muscle contractions due to exercise lead to the secretion of many proteins and proteoglycan peptides called myokines. Myostatin (MSTN) and Myogenin (MyoG) are two of the most important skeletal muscle growth regulatory factors related to myoblast differentiation and muscle hypertrophy. The present study aims at investigating the effects over eight weeks of high-intensity circuit training (HICT) on serum MyoG and MSTN in male soccer players.

METHOD

The present study is a quasi-experimental study on 21 male soccer players (Experimental group: n = 11, Control group: n = 10) (ages 15.0 ± 3.4 years, body mass 55.7 ± 7.8 kg, height 173.3 ± 8.0 cm, Body mass index 18.4 ± 1.9 kg m^-2, maximum oxygen uptake 61.89 ± 3.01 ml kg^-1 and the peak height velocity 14.5 ± 0.3 years). Participants were randomly divided into two groups: training group and a control group. The first resting blood samples were obtained in the morning-fasting state, and the second blood samples were obtained after the maximum aerobic test at pre- and post-HICT.

RESULTS

There were non-significant differences in resting serum values of MyoG (p = 0.309, p > 0.05) but significant differences in resting serum values of MSTN between the training and control groups after eight weeks of HICT (p = 0.003, p < 0.05). No significant differences were observed between groups in the acute response of serum values of MyoG (p = 0.413, p < 0.05) and MSTN (p = 0.465, p < 0.05) to the maximum aerobic test after eight weeks of HICT.

CONCLUSION

These results suggest that eight weeks of HICT can decrease the resting serum values of MSTN but not change the resting serum values of MyoG in male adolescent soccer players. Also, eight weeks of HICT does not affect the acute response of MSTN and MyoG after a maximum aerobic test.

Effect of sera from elite athletes on cytokine secretion and insulin signaling in preadipocytes and skeletal muscle cells

Introduction: The immunomodulatory effect of physical activity can impact insulin signaling differentially in adipose tissues and skeletal muscle cells, depending on sport intensity. In this study, the effect of serum from elite athletes with varying endurance levels and playing different power sports on cytokine secretion and insulin signaling in preadipocyte and skeletal muscle cell lines was investigated. Methods: Preadipocytes (3T3-L1) and skeletal muscle cells (C2C12) were cultured in media containing pooled sera from elite athletes who play high-endurance (HE), high-power (HP), or low-endurance/low-power (LE/LP) sports for 72 h. Secreted cytokines (IL-6 and TNF-alpha) were assessed in the supernatant, and insulin signaling phosphoproteins levels were measured in lysates following treatment using cells multiplex immunoassays. Results: Sera from LE/LP and HP induced TNF-α secretion in C2C12, while serum from HE reduced IL-6 secretion compared to non-athlete serum control. All elite athlete sera groups caused decreased insulin sensitivity in 3T3-L1 cells, whereas in C2C12 cells, only HE athlete serum reduced insulin signaling, while LE/LP and HP caused increased insulin sensitivity. Conclusion: Sera from elite athletes of different sport disciplines can affect the inflammatory status and insulin signaling of preadipocytes and myoblasts differently, with risk of developing insulin resistance. Furthermore, investigation of the functional relevance of these effects on exercise physiology and pathophysiology is warranted.

Differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability in athletes and non-athletes

The study investigated the differential response to a single bout of maximal incremental treadmill exercise between athletes and non-athletes without dry eyes regarding tear secretion, tear film stability, visual acuity (VA), and stereoacuity. Additionally, the study examined the effect of gender and the duration of exercise on exercise-induced changes. Study participants included young university students aged 18-25 years who were athletes (male/female: 13/13) or non-athletes (male/female: 17/9). Participants underwent an aerobic exercise session using a treadmill and following the laid down Bruce treadmill test protocol till exhaustion. Measurements were taken in the order of distance VA, stereopsis, non-invasive tear break-up time (TBUT), and phenol red thread test, at baseline and after the exercise regimen. Within- and between-subject analyses using multiple t-tests with correction for multiple comparisons were performed to determine differences before and after exercise in athletes and non-athletes. Subsequently, ANCOVA was used to assess the influence of gender and the duration of exercise. The mean age (SD) of the athletes and the non-athletes was 22.4 ± 2.1 years and 21.8 ± 2.1 years, respectively (p = 0.357). Before exercise, the athletes had higher TBUT than non-athletes (14.6 ± 2.9 s vs. 11.9 ± 3.8 s; p = 0.021), but no difference was observed in any other ocular measurements. After exercise, the athletes showed significant improvement in tear secretion with the basal tear secretion increasing from 22.3 ± 2.5 mm to 25.8 ± 1.7 mm (p < 0.001). The non-athletes on the other hand had a borderline increase in tear secretion from 21.42 ± 2.85 mm to 23.73 ± 2.68 mm (p = 0.08). Also, the TBUT was much improved in the athletes after exercise compared to the non-athletes (17.7 ± 2.7 s vs. 14.8 ± 2.9 s, p = 0.004). Additionally, exercise improved the VA indifferently between the groups, while stereoacuity was unchanged after exercise in either group. Gender had no influence on the differences in the tear function measures between athletes and non-athletes after exercise. The duration of exercise, however, showed a borderline effect on the tear film stability (p = 0.068) after exercise. Our findings support the differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability between athletes and non-athletes. Thus, increased physical fitness and the duration of exercise might be crucial in the improvement of tear function through aerobic exercise.

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.

Cancer Related Anemia: An Integrated Multitarget Approach and Lifestyle Interventions

Cancer is often accompanied by worsening of the patient's iron profile, and the resulting anemia could be a factor that negatively impacts antineoplastic treatment efficacy and patient survival. The first line of therapy is usually based on oral or intravenous iron supplementation; however, many patients remain anemic and do not respond. The key might lie in the pathogenesis of the anemia itself. Cancer-related anemia (CRA) is characterized by a decreased circulating serum iron concentration and transferrin saturation despite ample iron stores, pointing to a more complex problem related to iron homeostatic regulation and additional factors such as chronic inflammatory status. This review explores our current understanding of iron homeostasis in cancer, shedding light on the modulatory role of hepcidin in intestinal iron absorption, iron recycling, mobilization from liver deposits, and inducible regulators by infections and inflammation. The underlying relationship between CRA and systemic low-grade inflammation will be discussed, and an integrated multitarget approach based on nutrition and exercise to improve iron utilization by reducing low-grade inflammation, modulating the immune response, and supporting antioxidant mechanisms will also be proposed. Indeed, a Mediterranean-based diet, nutritional supplements and exercise are suggested as potential individualized strategies and as a complementary approach to conventional CRA therapy.

How N-Acetylcysteine Supplementation Affects Redox Regulation, Especially at Mitohormesis and Sarcohormesis Level: Current Perspective

Exercise frequently alters the metabolic processes of oxidative metabolism in athletes, including exposure to extreme reactive oxygen species impairing exercise performance. Therefore, both researchers and athletes have been consistently investigating the possible strategies to improve metabolic adaptations to exercise-induced oxidative stress. N-acetylcysteine (NAC) has been applied as a therapeutic agent in treating many diseases in humans due to its precursory role in the production of hepatic glutathione, a natural antioxidant. Several studies have investigated NAC’s possible therapeutic role in oxidative metabolism and adaptive response to exercise in the athletic population. However, still conflicting questions regarding NAC supplementation need to be clarified. This narrative review aims to re-evaluate the metabolic effects of NAC on exercise-induced oxidative stress and adaptive response developed by athletes against the exercise, especially mitohormetic and sarcohormetic response.

Role of Interleukin-6 in Vascular Health and Disease

IL-6 is usually described as a pleiotropic cytokine produced in response to tissue injury or infection. As a pro-inflammatory cytokine, IL-6 activates innate and adaptative immune responses. IL-6 is released in the innate immune response by leukocytes as well as stromal cells upon pattern recognition receptor activation. IL-6 then recruits immune cells and triggers B and T cell response. Dysregulated IL-6 activity is associated with pathologies involving chronic inflammation and autoimmunity, including atherosclerosis. However, IL-6 is also produced and released under beneficial conditions, such as exercise, where IL-6 is associated with the anti-inflammatory and metabolic effects coupled with physical adaptation to intense training. Exercise-associated IL-6 acts on adipose tissue to induce lipogenesis and on arteries to induce adaptative vascular remodeling. These divergent actions could be explained by complex signaling networks. Classical IL-6 signaling involves a membrane-bound IL-6 receptor and glycoprotein 130 (gp130), while trans-signaling relies on a soluble version of IL-6R (sIL-6R) and membrane-bound gp130. Trans-signaling, but not the classical pathway, is regulated by soluble gp130. In this review, we discuss the similarities and differences in IL-6 cytokine and myokine signaling to explain the differential and opposite effects of this protein during inflammation and exercise, with a special focus on the vascular system.

Changes in Inflammatory Cytokines and Irisin in Response to High Intensity Swimming in Adolescent versus Adult Male Swimmers

Swimming is a popular youth sport that is considered beneficial for cardiovascular fitness. However, the potential inflammatory outcomes of high intensity swimming in younger swimmers are unclear, as is the response of irisin, a myokine released during exercise with anti-inflammatory properties. This study compared the plasma concentrations of interleukins 1-beta (IL-1β), 6 (IL-6), 10 (IL-10), tumor necrosis factor alpha (TNF-α) and irisin in response to intense swimming between adolescent and adult male swimmers. Thirty-two swimmers (16 adolescents, 14 ± 1 years; 16 adults, 21.5 ± 3.1 years) completed a high intensity interval swimming trial. At rest, only TNF-α was higher (33%, p < 0.05) in adolescents compared with adults. There was an overall significant increase in IL-1β from pre- to post-swimming (3% in adolescents, 24% in adults), but no significant interaction. IL-10 significantly increased in both groups (+34% in adolescents, +56% in adults). IL-6 and TNF-α increased significantly (+32% and +26%, respectively) in adults, but not in adolescents (+2% and -9%, respectively). Adults showed a small, but significant decrease in irisin (-5%), with no change in adolescents. The lack of an IL-6, TNF-α and irisin response to intense swimming in adolescent swimmers may suggest a blunted inflammatory and myokine response following high intensity exercise in trained youth.

Inflammatory responses to acute exercise during pulmonary rehabilitation in patients with COPD

Objective

Pulmonary rehabilitation is a cornerstone treatment in the management of chronic obstructive pulmonary disease (COPD). Acute bouts of exercise can lead to short bursts of inflammation in healthy individuals. However, it is unclear how COPD patients respond to acute bouts of exercise. This study assessed inflammatory responses to exercise in COPD patients at the start (phase 1) and end (phase 2) of pulmonary rehabilitation.

Methods

Blood samples were collected before and after an acute exercise bout at the start (phase 1, n = 40) and end (phase 2, n = 27) of pulmonary rehabilitation. The primary outcome was change in fibrinogen concentrations. Secondary outcomes were changes in CRP concentrations, total/differential leukocyte counts, markers of neutrophil activation (CD11b, CD62L and CD66b), and neutrophil subsets (mature, suppressive, immature, progenitor).

Results

Acute exercise (phase 1) did not induce significant changes in fibrinogen (p = 0.242) or CRP (p = 0.476). Total leukocyte count [mean difference (MD), 0.5 ± 1.1 (10⁹ L⁻¹); p = 0.004], neutrophil count [MD, 0.4 ± 0.8 (10⁹ L⁻¹); p < 0.001], and immature neutrophils (MD, 0.6 ± 0.8%; p < 0.001) increased post-exercise. Neutrophil activation markers, CD11b (p = 0.470), CD66b (p = 0.334), and CD62L (p = 0.352) were not significantly altered post-exercise. In comparison to the start of pulmonary rehabilitation (phase 2), acute exercise at the end of pulmonary rehabilitation led to a greater fibrinogen response (MD, 84 mg/dL (95% CI − 14, 182); p = 0.045).

Conclusion

An acute bout of exercise does not appear to induce significant alterations in the concentrations of inflammatory mediators but can increase white blood cell subsets post-exercise. A greater fibrinogen response to acute exercise is seen at the end of pulmonary rehabilitation when compared to the start. Further research is required to understand the clinical context of these acute inflammatory responses to exercise.

Inflammation, physical activity, and chronic disease: An evolutionary perspective

Low-grade inflammation is emerging as a common feature of contemporary metabolic, psychiatric, and neurodegenerative diseases. Both physical inactivity and abdominal adiposity are associated with persistent systemic low-grade inflammation. Thus, the behavioral, biological, and physiological changes that cause a predisposition to obesity and other co-morbidities could have epigenetic underpinnings in addition to various evolutionary scenarios. A key assumption involves the potential for a mismatch between the human genome molded over generations, and the issue of adapting to the modern high calorie diet and common built environments promoting inactivity. This biological mismatch appears to have dire health consequences. Therefore, the goal of this article is to provide a brief overview on the importance of inflammation as part of human survival and how physical activity (PA) and physical inactivity are critical regulators of systemic inflammation. The review will highlight anti-inflammatory effects of PA and exercise training from a metabolic and systemic signaling perspective, which includes skeletal muscle to utilization of fatty acids, TLR4 signaling, and myokine/adipokine effects. The available evidence suggests that PA, regular exercise, and weight loss offer both protection against and treatment for a wide variety of chronic diseases associated with low-grade inflammation through an improved inflammatory profile.

Does chronic high-intensity endurance training have an effect on cardiovascular markers of active populations and athletes? Systematic review and meta-analysis

OBJECTIVE

The objective of this study was to ascertain the effects of high-intensity chronic endurance training on cardiovascular markers of active populations and athletes.

METHODS

This review was conducted in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We used databases of PubMed, Science Direct, SPORTDiscus, Google Scholar and grey literatures with Mesh and free-text search as well as manual searches to identify relevant studies from June 2017 to September 2019. Weighted standardised mean differences and effect size of the intervention group versus the control group were calculated using a random effect model with 95% CI.

RESULT

There was significant improvement in high-density lipoprotein with weighted standardised mean difference and effect size=-1.06 (-1.83 to -0.30), p=0.006. We have also observed a significant reduction in low-density lipoprotein and total cholesterol with weighted standardised mean difference and effect size=-0.97 (-1.58 to -0.36), p=0.002, and = -0.78 (-1.34 to -0.22), p=0.007, respectively. There was a significant reduction in interleukin 6 (IL-6) using a fixed effect model with weighted standardised mean difference and effect size=-0.87 (-1.33 to -0.40), p=0.0003 and C reactive protein (CRP) with weighted standardised mean differences and effect size=-0.41 (-0.73 to -0.09), p=0.01.

CONCLUSION

Chronic high-intensity endurance training improves healthy lipid profiles (increase high-density lipoprotein, decreased low-density lipoprotein and total cholesterol). And decreased inflammatory markers (IL-6 and CRP) independent of age and sex and cannot be associated with an increased risk of developing cardiovascular disease.

PROSPERO REGISTRATION NUMBER

CRD 42017081369.

Modality-specific training adaptations - do they lead to a dampened acute inflammatory response to exercise?

While adaptations to a short-term training program can dampen the acute inflammatory response to exercise, less is known about the influence of chronic modality-specific adaptations to training. This study compares the acute inflammatory response to upper- and lower-body interval exercise in individuals chronically trained in these respective modalities. Ninety minutes of interval exercise matched for relative power output on an arm-crank (ARM) and cycle ergometer (LEG) was performed by 8 trained paddlers and 8 trained cyclists. Blood samples were taken before and after exercise. Interleukin-6 (IL-6) concentrations were analysed in plasma, while the expression of intracellular heat shock protein 72 (iHsp72) was assessed in monocytes. IL-6 was increased following both modalities (fold change - ARM: 7.23 ± 3.56, p < 0.001; LEG: 9.03 ± 4.82, p < 0.001), in both groups (cyclists, p < 0.001; paddlers, p < 0.001), but the increase was smaller in ARM compared with LEG (time × modality, p < 0.001). ARM induced a smaller iHsp72 response compared with LEG (fold change - ARM: 1.07 ± 0.14, p = 0.102; LEG: 1.18 ± 0.14, p < 0.001; time × modality, p = 0.039). Following ARM, iHsp72 expression was increased in the cyclists only (fold change cyclists: 1.12 ± 0.11, p = 0.018; paddlers: 1.03 ± 0.17, p = 0.647), while iHsp72 expression following LEG was increased in both groups (fold change cyclists: 1.14 ± 0.15, p = 0.027; paddlers: 1.22 ± 0.13, p < 0.001). Taken together, the acute inflammatory response to lower-body interval exercise was larger compared with work-matched upper-body interval exercise. Moreover, adaptations to upper-body exercise training dampened the iHsp72 response to this modality. Therefore, exercise may be less effective in reducing chronic low-grade inflammation in individuals relying on their upper body, such as wheelchair users.

A comparison of isomaltulose versus maltodextrin ingestion during soccer-specific exercise

Purpose

The performance and physiological effects of isomaltulose and maltodextrin consumed intermittently during prolonged soccer-specific exercise were investigated.

Methods

University soccer players (n = 22) performed 120 min of intermittent exercise while consuming 8% carbohydrate–electrolyte drinks (equivalent to ~ 20 g h⁻¹) containing maltodextrin (Glycaemic Index: 90–100), isomaltulose (Glycaemic Index: 32) or a carbohydrate-energy-free placebo in a manner replicating the practices of soccer players (i.e., during warm-up and half-time). Physical (sprinting, jumping) and technical (shooting, dribbling) performance was assessed.

Results

Blood glucose and plasma insulin (both P < 0.001) concentrations varied by trial with isomaltulose maintaining > 13% higher blood glucose concentrations between 75 and 90 min versus maltodextrin (P < 0.05). A decline in glycaemia at 60 min in maltodextrin was attenuated with isomaltulose (−19 versus −4%; P = 0.015). Carbohydrates attenuated elevations in plasma epinephrine concentrations (P < 0.05), but isomaltulose proved most effective at 90 and 120 min. Carbohydrates did not attenuate IL-6 increases or reductions in physical or technical performances (all P > 0.05). Ratings of abdominal discomfort were influenced by trial (P < 0.05) with lower values for both carbohydrates compared to PLA from 60 min onwards.

Conclusions

Although carbohydrates (~ 20 g h⁻¹) did not attenuate performance reductions throughout prolonged soccer-specific exercise, isomaltulose maintained higher blood glucose at 75–90 min, lessened the magnitude of the exercise-induced rebound glycaemic response and attenuated epinephrine increases whilst maintaining similar abdominal discomfort values relative to maltodextrin. When limited opportunities exist to consume carbohydrates on competition-day, low-glycaemic isomaltulose may offer an alternative nutritional strategy for exercising soccer players.

Exercise-induced cytokine changes in antigen stimulated whole-blood cultures compared to serum

Strenuous exercise is followed by an elevation of many cytokines with inflammation regulating properties. Since most cytokines act at pico- or nanomolar concentrations many investigations failed to detect their concentrations in vivo. Hence, the aim of this study was to evaluate the significance of cytokine measurements (IL-1β, TNF-α, IL-1ra, IL-6, CCL2 and CXCL8) in a stimulated whole-blood culture (sWBC) compared to serum with respect to their exercise-induced kinetics and detection rates. 40 male volunteers (age: 25,5±4,3years, BMI: 24,00±2,24, VO₂peak: 46,9±4,1mL/kg×min) performed 60min of intensive bicycle exercise (80% VO₂peak). Blood samples were taken before and for up to 24h after exercise. All cytokines were determined by a multiplex ELISA. There were weak to moderate correlations between cytokines in sWBC and serum. While exercise did not affect pro-inflammatory cytokines in serum, in sWBC only IL-1β was increased 1.2-fold at 3h (p<0,05). All other cytokines increased both in sWBC and serum. The detection rate was superior in sWBC vs serum for most cytokines. Exercise-induced cytokine kinetics in sWBC do not reflect systemic changes. Both approaches provide a synergistic insight into inflammatory processes on the cytokine level.

Influence of exhaustive aerobic exercise on some cytokines and serum iron parameters in canine experimental model

The aim of the experiment was to study the effect of exhaustive exercise on some cytokines and iron status parameters. We used 12 male, mongrel dogs divided into two groups – animals from experimental group were submitted to exercise at moderate intensity with exhaustion as the end-point; animals from control group did no exercise. Serum levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), hepcidin prohormone, serum iron (SI), total iron binding capacity (TIBC) and transferrin saturation (TS) were measured before exercise (BE), right after exercise (0 hour) and on 2, 4, 24, 48 and 72 hours after exercise. SI, TIBC and TS were measured also on day 7 and 14 after exercise. Serum levels of TNF-α increased after the exhaustive exercise. Serum levels of IL-6 demonstrated an increase at 0 hour, but increase was not statistically significant compared to BE level. Serum levels of hepcidin prohormone marked a slight increase 48 hours after the exercise, but change was insignificant. Levels of SI decreased on hour 72 (P<0.01) and on day 7 (P<0.01) and 14 (P<0.05) after the exercise, as compared to BE level. Similar were changes in TS. TIBC decreased on 4, 24 and 72 hours (P<0.05) after exercise, but only compared to control group. In conclusion, exhaustive exercise causes inflammatory response and a significant decrease in SI levels.

Effects of Acute Endurance Exercise on Plasma Protein Profiles of Endurance-Trained and Untrained Individuals over Time

Acute physical exercise and repeated exercise stimuli affect whole-body metabolic and immunologic homeostasis. The aim of this study was to determine plasma protein profiles of trained (EET, n = 19) and untrained (SED, n = 17) individuals at rest and in response to an acute bout of endurance exercise. Participants completed a bicycle exercise test at an intensity corresponding to 80% of their VO_2max. Plasma samples were taken before, directly after, and three hours after exercise and analyzed using multiplex immunoassays. Seventy-eight plasma variables were included in the final analysis. Twenty-nine variables displayed significant acute exercise effects in both groups. Seven proteins differed between groups, without being affected by acute exercise. Among these A2Macro and IL-5 were higher in EET individuals while leptin showed elevated levels in SED individuals. Fifteen variables revealed group and time differences with elevated levels for IL-3, IL-7, IL-10, and TNFR2 in EET individuals. An interaction effect could be observed for nine variables including IL-6, MMP-2, MMP-3, and muscle damage markers. The proteins that differ between groups indicate a long-term exercise effect on plasma protein concentrations. These findings might be of importance in the development of exercise-based strategies in the prevention and therapy of chronic metabolic and inflammatory diseases and for training monitoring.

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.

Comparison of inflammatory responses to a soccer match between elite male and female players

The aim of this study was to compare the inflammatory responses between male and female soccer players for a period of 48 hours after an official match. Blood samples were taken from 83 subjects (22 elite male and 21 elite female soccer players and 20 male and 20 female inactive individuals) in the morning of the game day, immediately after the soccer game and 24 and 48 hours after the match. Average relative exercise intensity during the match was similar in male and female players, as indicated by mean heart rate that was 86.9 ± 4.3 and 85.6 ± 2.3% of maximal heart rate (p = 0.23), respectively. Interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) increased 2- to 4-fold above resting values, peaking immediately after the match. C-reactive protein (CRP) and creatine kinase peaked 24 hours after the match. Interleukin 6, CRP, and creatine kinase responses were similar in male and female players, but the peak in TNF-α was 18% higher in male players. Interleukin 6, TNF-α, and CRP at rest were lower in male and female players compared with the control subjects, suggesting a protective effect of regular exercise training regarding the inflammatory profile. The results of this study show that a soccer match induces significant inflammatory responses in both male and female players, with only TNF-α peak values being lower in females. Because of the effects of inflammatory responses on performance and health of the players, it is suggested that coaches and trainers should adjust exercise training programs after a match to promote recovery and protect the athletes' health.

A therapeutic role for vitamin D on obesity-associated inflammation and weight-loss intervention

Vitamin D plays an essential role in the regulation of skeletal metabolism as well as calcium and phosphate homeostasis, while vitamin D receptor (VDR) regulates de novo lipid synthesis, thereby contributing to the development of obesity. Furthermore, obese individuals are at a greater risk for vitamin D deficiency which may increase the potential risk for chronic inflammation, insulin resistance, and metabolic syndrome. While acute exercise enhances the activation of inflammatory signaling pathways, chronic exercise training may attenuate elevated pro-inflammatory cytokine production, resulting in the improvement of cardiovascular and metabolic health in obese individuals. Supplementation with vitamin D coupled with exercise or mild caloric restriction has been shown to improve markers of fitness and inflammation as well as cholesterol. Therefore, this review primarily addresses the impact of vitamin D deficiency in obesity-related inflammatory imbalances and how exercise and weight-loss interventions may enhance the beneficial effects on vitamin D-mediated inflammation in obesity.

Coronary and muscle blood flow during physical exercise in humans; heterogenic alliance

In this review, we present the relation between power generation capabilities and pulmonary oxygen uptake during incremental cycling exercise in humans and the effect of exercise intensity on the oxygen cost of work. We also discuss the importance of oxygen delivery to the working muscles as a factor determining maximal oxygen uptake in humans. Subsequently, we outline the importance of coronary blood flow, myocardial oxygen uptake and myocardial metabolic stability for exercise tolerance. Finally, we describe mechanisms of endothelium-dependent regulation of coronary and skeletal muscle blood flow, dysregulation of which may impair exercise capacity and increase the cardiovascular risk of exercise.

Effects of 8-week combined training on body composition, isokinetic strength, and cardiovascular disease risk factors in older women

BACKGROUND AND AIMS

Decline in muscle endurance and strength as well as attenuated cardiac function with aging not only leads to overall physical function decline but also has a close relationship with cardiovascular disease occurrence. This study examined the effects of an 8-week combined training program (i.e., consisting of both aerobic and resistance training) on body composition, isokinetic strength, and cardiovascular disease (CVD) risk factors in older women.

METHODS

Nineteen women, aged 65-75 years, were randomly assigned to either a combined training (CT, n = 9) or an aerobic training (AT, n = 10) group. Body composition and isokinetic strength were assessed before and after the exercise program. Blood samples were collected to identify CVD risk factors.

RESULTS

At the end of the training program, body mass, body fat mass, percent body fat, and body mass index decreased significantly and lean mass increased significantly in the CT group compared with those in the AT group (p < 0.05). Isokinetic strength was also significantly greater in the CT group than in the AT group (p < 0.05). In addition, the C-reactive protein level was significantly lower in the CT group than in the AT group, whereas interleukin-6, tumor necrosis factor-α, and total cholesterol levels were significantly lower in both groups (p < 0.05).

CONCLUSIONS

An 8-week combined exercise program benefits body composition, especially lean mass, and positively affects isokinetic strength and CVD risk factors. Therefore, increasing lean mass and strength by continuously participating in a combined exercise program may be an effective treatment for preventing and improving CVD in older women.

Effect of Aerobic Exercise Training on MDA and TNF- α Levels in Patients with Type 2 Diabetes Mellitus

Objective. Diabetes mellitus (DM) is associated with low-grade inflammation. The benefits of regular exercise for the DM are well established, whereas less is known about the impact of aerobic exercise on malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-α) in the DM. Methods. We randomised 64 participants, who do not exercise regularly, without any diabetic chronic complications in parallel to 12 weeks of aerobic exercise (three times per week, n = 31) and no exercise (control; n = 33). Plasma levels of soluble TNF-α and MDA levels were measured before-after physical training programme and control group. Results. Sixty-four patients with type 2 diabetes mellitus were analysed. When comparing the two groups of patients with age, gender, hemoglobin A1c (HbA1c) levels, lipid profile, waist circumference, body mass index (BMI) and class of treatment for diabetes were not different between groups. While soluble TNF-α remained essentially unaffected by physical training, plasma concentrations of MDA markedly decreased (P < 0.05); physical training also decreased body weight, waist circumference, and blood pressure (P < 0.05). Conclusion. Exercise training favorably affected body weight, waist circumference, and blood pressure. A three-weekly, 12-week, aerobic-training programme, without a concomitant weight loss diet, was associated with significant decrease in MDA levels in type 2 diabetic individuals.

The fatty acid amide hydrolase in lymphocytes from sedentary and active subjects

PURPOSE

Endocannabinoids (eCB) and interleukin 6 (IL-6) levels change during physical activity, thus suggesting their involvement in the modulation of exercise-related processes like inflammation and energy homeostasis. To investigate whether lifestyle might affect the activity of the eCB-degrading enzyme fatty acid amide hydrolase (FAAH), active and sedentary subjects were enrolled.

METHODS

Plasma IL-6 levels and lymphocyte FAAH activity of eight physically active male subjects (mean ± SEM; age = 39.3 ± 2.9 yr, body mass index = 21.1 ± 0.4 kg·m), usually practicing aerobic exercise (8.1 ± 1.2 h·wk), and eight sedentary subjects (38.8 ± 3.7 yr, body mass index = 23.1 ± 0.8 kg·m) were measured. Also, in vitro effect of IL-6 was tested on FAAH expression and activity and on FAAH promoter activity in lymphocytes from sedentary subjects.

RESULTS

Under resting conditions (at least 12 h from the last exercise), the active group showed plasma IL-6 levels (2.74 ± 0.73 pg·mL) and lymphocyte FAAH activity (215.7 ± 38.5 pmol·min·mg protein) significantly higher than those measured in the sedentary group (0.20 ± 0.02 pg·mL, and 42.0 ± 4.2 pmol·min·mg protein). Increased IL-6 levels paralleled increased FAAH activity, and consistently, the in vitro treatment of lymphocytes from sedentary individuals with 10 ng·mL IL-6 for 48 h significantly increased FAAH expression and activity. Transient transfection experiments showed that IL-6 induced the expression of a reporter gene under the control of a cAMP response element-like region in the human FAAH promoter. A mutation in the same element abolished IL-6 up-regulation, demonstrating that this cytokine regulates FAAH activity at the transcriptional level.

CONCLUSION

IL-6 leads to activation of the FAAH promoter, thus enhancing FAAH activity that modulates the eCB tone in physically active people.

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.

The treatment strategies of autoimmune disease may need a different approach from conventional protocol: a review

Autoimmune disease (AD) is one of the emerging noncommunicable diseases. Remission is a possibility in AD, but current treatment strategies are not able to achieve this. We have well-established protocols for infections, oncology, metabolic diseases, and transplantation which are often used as models for the management of AD. Studies and observations suggest that in contrast to diseases used as a role model, AD has wide variability, different causative and pathogenic process, which is highly dynamic, making the current treatment strategies to fall short of expected complete remission. In this brief review, it is attempted to highlight the current understanding of AD and the probable gaps in the treatment strategies. Few hypothetical suggestions to modify the treatment protocols are presented.

Potential beneficial effects of whole-body vibration for muscle recovery after exercise

Whole-body vibration is an emerging strategy used by athletes and exercising individuals to potentially accelerate muscle recovery. The vibration elicits involuntary muscle stretch reflex contractions leading to increased motor unit recruitment and synchronization of synergist muscles, which may lead to greater training adaptations over time. Intense exercise training, especially eccentric muscle contractions, will inevitably lead to muscle damage and delayed onset muscle soreness, which may interfere with the maintenance of a planned training program. Whole-body vibration before and after exercise shows promise for attenuating muscle soreness and may be considered as an adjunct to traditional therapies (i.e., massage, cryotherapy) to accelerate muscle recovery.

Immobilization increases interleukin-6, but not tumour necrosis factor-α, release from the leg during exercise in humans

Data on interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) release during acute exercise are not conclusive, and information is lacking about the impact of physical inactivity. Some studies have shown an increase, but others report no changes in IL-6 and TNF-α release during exercise. We have now studied the temporal relationship of leg IL-6 and TNF-α release before and during isolated two-legged exercise after 14 days of one-leg immobilization (IM) while the other leg served as the control (CON) leg. Fifteen healthy male subjects (mean ± SEM age, 23 ± 1 years; body mass index, 23.6 ± 0.7 kg m(-2); and maximal oxygen uptake, 46.8 ± 1.4 ml kg(-1) min(-1)) performed 45 min of two-legged dynamic knee-extensor exercise at 19.6 ± 0.8 W. Arterial and femoral venous blood samples from the CON and the IM leg were collected every 15 min during exercise, and leg blood flow was measured with Doppler ultrasound. The arterial plasma IL-6 concentration increased (P < 0.05) with exercise (rest, 1.3 ± 0.1 pg ml(-1); 15 min, 1.9 ± 0.2 pg ml(-1); 30 min, 2.4 ± 0.2 pg ml(-1); and 45 min, 3.1 ± 0.3 pg ml(-1)). Interleukin-6 release occurred after 15 min of exercise, and the release from the IM leg was significantly greater compared with the CON leg after 45 min (1114 ± 152 versus 606 ± 14 pg min(-1), respectively, P < 0.05). Tumour necrosis factor-α release did not differ between the CON and the IM leg, and arterial concentrations remained unchanged during exercise (P > 0.05). In conclusion, prior immobilization enhances release of IL-6 from the leg during exercise at a moderate workload, and the release is already present in the early phase of exercise. Neither immobilization nor exercise had an effect on TNF-α release in the working legs.

Increase in IL-6, TNF-α, and MMP-9, but not sICAM-1, concentrations depends on exercise duration

It has been suggested that exercise intensity is of importance in the regulation of increase in pro-inflammatory molecules, but there is still a debate about the effect of duration on these molecules. Therefore, the effect of exercise duration on the serum concentrations of interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), soluble form of intercellular adhesion molecule-1 (sICAM-1), and matrix metalloproteinase-9 (MMP-9) was studied in 22 half-marathon (HM) and 18 marathon (M) male amateur runners who completed their exercise task in 1.8 ± 0.2 (mean ± standard deviation) and 3.6 ± 0.4 h, respectively (thus, average speed was 11.7 ± 1.5 and 11.9 ± 1.8 km h(-1), respectively). Blood was sampled 2 days before, 15 min after, and 28 h after the race. IL-6, TNF-α, and MMP-9 always increased immediately after exercise, but the increase was larger (P < 0.05) in M versus HM (∆IL-6: 31 ± 24 vs. 5 ± 4 pg ml(-1); ∆TNF-α: 1.7 ± 1.9 vs. 0.5 ± 0.8 pg ml(-1); MMP-9: 288 ± 216 vs. 145 ± 128 ng ml(-1), respectively). sICAM-1 also increased with exercise, but similarly in M and HM (20 ± 40 vs. 23 ± 32 ng ml(-1), respectively). Only sICAM-1 remained elevated 28 h post-exercise in both HM and M, while IL-6, TNF-α, and MMP-9 returned to pre-exercise levels. Competitive HM and M races induce significant increases in IL-6, TNF-α, sICAM-1, and MMP-9 concentrations. As HM and M runners performed the competition with similar absolute intensity, the difference in response between the groups suggests that exercise duration is of importance in the regulation of IL-6, TNF-α, and MMP-9, but not sICAM-1 concentrations in response to prolonged running.

The LIM-only protein FHL2 regulates interleukin-6 expression through p38 MAPK mediated NF-κB pathway in muscle cells

Interleukin 6 (IL-6) is pleiotropic cytokine playing an important role in inflammatory response. Other than classical immune tissues, IL-6 is also produced in muscle cells under specific conditions. Four-and-a-half LIM-only protein 2 (FHL2) is preferentially expressed in skeletal and cardiac muscle cells compared to other tissues indicating it has an important role in skeletal muscle and cardiovascular system. In this report, the regulation of IL-6 by FHL2 in muscle cells was investigated. We demonstrated that FHL2 overexpression increased IL-6 mRNA level and its protein secretion in skeletal myoblasts. In contrast, the IL-6 secretion was significantly decreased after FHL2-knockdown by siRNA in response to TNFα stimulation. We further showed that FHL2-mediated induction of IL-6 was regulated by the activation of IL-6 promoter through stimulating NF-κB and p38 MAPK signaling pathway. Our results further illustrated the molecular mechanisms of IL-6 production, which provides new insights in the roles of FHL2 in post-injury inflammation or cytoprotection of muscle cells.

Functional performance and inflammatory cytokines after squat exercises and whole-body vibration in elderly individuals with knee osteoarthritis

OBJECTIVE

To investigate the effects of squat exercises combined with whole-body vibration on the plasma concentration of inflammatory markers and the functional performance of elderly individuals with knee osteoarthritis (OA).

DESIGN

Clinical, prospective, randomized, single-blinded study.

SETTING

Exercise physiology laboratory.

PARTICIPANTS

Elderly subjects with knee OA (N=32) were divided into 3 groups: (1) squat exercises on a vibratory platform (platform group, n=11); (2) squat exercises without vibration (squat group, n=10); and (3) the control group (n=11).

INTERVENTIONS

The structured program of squat exercises in the platform and squat groups was conducted 3 times per week, on alternate days, for 12 weeks.

MAIN OUTCOME MEASURES

Plasma soluble tumor necrosis factor-α receptors 1 (sTNFR1) and 2 (sTNFR2) were measured using immunoassays (the enzyme-linked immunosorbent assay method). The Western Ontario and McMaster Universities Osteoarthritis Index questionnaire was used to evaluate self-reported physical function, pain, and stiffness. The 6-minute walk test, the Berg Balance Scale, and gait speed were used to evaluate physical function.

RESULTS

In the platform group, there were significant reductions in the plasma concentrations of the inflammatory markers sTNFR1 and sTNFR2 (P<.001 and P<.05, respectively) and self-reported pain (P<.05) compared with the control group, and there was an increase in balance (P<.05) and speed and distance walked (P<.05 and P<.001, respectively). In addition, the platform group walked faster than the squat group (P<.01).

CONCLUSIONS

The results suggest that whole-body vibration training improves self-perception of pain, balance, gait quality, and inflammatory markers in elderly subjects with knee OA.

Role of vitamin C and E supplementation on IL-6 in response to training

Vitamin C and E supplementation has been shown to attenuate the acute exercise-induced increase in plasma interleukin-6 (IL-6) concentration. Here, we studied the effect of antioxidant vitamins on the regulation of IL-6 expression in muscle and the circulation in response to acute exercise before and after high-intensity endurance exercise training. Twenty-one young healthy men were allocated into either a vitamin (VT; vitamin C and E, n = 11) or a placebo (PL, n = 10) group. A 1-h acute bicycling exercise trial at 65% of maximal power output was performed before and after 12 wk of progressive endurance exercise training. In response to training, the acute exercise-induced IL-6 response was attenuated in PL (P < 0.02), but not in VT (P = 0.82). However, no clear difference between groups was observed (group × training: P = 0.13). Endurance exercise training also attenuated the acute exercise-induced increase in muscle-IL-6 mRNA in both groups. Oxidative stress, assessed by plasma protein carbonyls concentration, was overall higher in the VT compared with the PL group (group effect: P < 0.005). This was accompanied by a general increase in skeletal muscle mRNA expression of antioxidative enzymes, including catalase, copper-zinc superoxide dismutase, and glutathione peroxidase 1 mRNA expression in the VT group. However, skeletal muscle protein content of catalase, copper-zinc superoxide dismutase, or glutathione peroxidase 1 was not affected by training or supplementation. In conclusion, our results indicate that, although vitamin C and E supplementation may attenuate exercise-induced increases in plasma IL-6 there is no clear additive effect when combined with endurance training.

Effects of light emitting diode (LED) therapy and cold water immersion therapy on exercise-induced muscle damage in rats

The aim of this work is to analyze the effects of LED therapy at 940 nm or cold water immersion therapy (CWI) after an acute bout of exercise on markers of muscle damage and inflammation. Thirty-two male Wistar rats were allocated into four groups: animals kept at rest (control), exercised animals (E), exercised + CWI (CWI), and exercised + LED therapy (LED). The animals swam for 100 min, after which blood samples were collected for lactate analysis. Animals in the E group were returned to their cages without treatment, the CWI group was placed in cold water (10°C) for 10 min and the LED group received LED irradiation on both gastrocnemius muscles (4 J/cm(2) each). After 24 h, the animals were killed and the soleus muscles were submitted to histological analysis. Blood samples were used for hematological and CK analyses. The results demonstrated that the LED group presented fewer areas of muscle damage and inflammatory cell infiltration and lower levels of CK activity than the E group. Fewer areas of damaged muscle fiber were observed in the LED group than in CWI. CWI and LED did not reduce edema areas. Hematological analysis showed no significant effect of either treatment on leukocyte counts. The results suggest that LED therapy is more efficient than CWI in preventing muscle damage and local inflammation after exercise.

Moderate intensity physical training accelerates healing of full-thickness wounds in mice

Physical training influences the cells and mediators involved in skin wound healing. The objective of this study was to determine the changes induced by different intensities of physical training in mouse skin wound healing. Ninety male C57BL6 mice (8 weeks old, 20-25 g) were randomized into three physical training groups: moderate (70% VO2max), high (80% VO2max), and strenuous intensity (90% VO2max). Animals trained on a motorized treadmill for 8 weeks (E lesion: physical training until the day of excisional lesion, N = 10) or 10 weeks (E euthan: physical training for 2 additional weeks after excisional lesion until euthanasia, N = 10), five times/week, for 45 min. Control groups (CG) trained on the treadmill three times/week only for 5 min (N = 10). In the 8th week, mice were anesthetized, submitted to a dorsal full-thickness excisional wound of 1 cm², and sacrificed 14 days after wounding. Wound areas were measured 4, 7, and 14 days after wounding to evaluate contraction (d4, d7 and d14) and re-epithelialization (d14). Fragments of lesion and adjacent skin were processed and submitted to routine histological staining. Immunohistochemistry against alpha-smooth muscle actin (α-SMA) was performed. Moderate-intensity training (M) until lesion (M/E lesion) led to better wound closure 7 days after wounding compared to controls and M/E euthan (P < 0.05), and both moderate-intensity groups showed better re-epithelialization rates than controls (M/E lesion = 85.9%, M/E euthan = 96.4% and M/CG = 79.9%; P < 0.05). Sections of M/E lesion and M/E euthan groups stained with hematoxylin-eosin, Picrosirius red and α-SMA showed the most mature granulation tissues among all trained groups and controls. Thus, moderate-intensity physical training improves skin wound healing.

Peripheral signals of energy homeostasis as possible markers of training stress in athletes: a review

The importance of physical exercise in regulating energy balance and ultimately body mass is widely recognized. There have been several investigative efforts in describing the regulation of the energy homeostasis. Important in this regulatory system is the existence of several peripheral signals that communicate the status of body energy stores to the hypothalamus including leptin, adiponectin, ghrelin, interleukin-6, interleukin-1β, and tumor necrosis factor-α--different cytokines and other peptides that affect energy homeostasis. In certain circumstances, all these peripheral signals may be used to reveal the condition of the athlete as the result of several months of prolonged exercise training. These hormone and cytokine concentrations characterize a physical stress condition in which different hormone and cytokine responses are apparently linked to changes in physical performance. The possibility to use these peripheral signals as markers of training stress (and possible overreaching/overtraining) in elite athletes should be considered. These measured hormone and cytokine levels could also be used to characterize the physical stress of single exercise session, as the hormone and cytokine response to exercise may actually be a response to the concurrent energy deficit. In summary, different peripheral signals of energy homeostasis may be sensitive to changes in specific training stress and may be useful for predicting the onset of possible overreaching/overtraining in athletes.

Athletic humans and horses: comparative analysis of interleukin-6 (IL-6) and IL-6 receptor (IL-6R) expression in peripheral blood mononuclear cells in trained and untrained subjects at rest

BACKGROUND

Horses and humans share a natural proclivity for athletic performance. In this respect, horses can be considered a reference species in studies designed to optimize physical training and disease prevention. In both species, interleukin-6 (IL-6) plays a major role in regulating the inflammatory process induced during exercise as part of an integrated metabolic regulatory network. The aim of this study was to compare IL-6 and IL-6 receptor (IL-6R) mRNA expression in peripheral blood mononuclear cells (PBMCs) in trained and untrained humans and horses.

RESULTS

Nine highly trained male swimmers (training volume: 21.6 ± 1.7 h/wk in 10-12 sessions) were compared with two age-matched control groups represented by eight lightly trained runners (training volume: 6.4 ± 2.6 h/wk in 3-5 sessions) and nine untrained subjects. In addition, eight trained horses (training volume: 8.0 ± 2.1 h/wk in 3-4 sessions) were compared with eight age-matched sedentary mares. In humans, IL-6 mRNA levels in PBMCs determined by quantitative reverse transcription-polymerase chain reaction were significantly higher in highly trained subjects, whereas IL-6R expression did not differ among groups. In horses, transcripts of both IL-6 and IL-6R were significantly up-regulated in the trained group.

CONCLUSIONS

Up-regulation of IL-6R expression in PBMCs in horses could reflect a mechanism that maintains an adequate anti-inflammatory environment at rest through ubiquitous production of anti-inflammatory cytokines throughout the body. These findings suggest that the system that controls the inflammatory response in horses is better adapted to respond to exercise than that in humans.

Effects of resistance training on the inflammatory response

Resistance training (RT) is associated with reduced risk of low grade inflammation related diseases, such as cardiovascular disease and type 2 diabetes. The majority of the data studying cytokines and exercise comes from endurance exercise. In contrast, evidence establishing a relationship between RT and inflammation is more limited. This review focuses on the cytokine responses both following an acute bout, and after chronic RT. In addition, the effect of RT on low grade systemic inflammation such as individuals at risk for type 2 diabetes is reviewed. Cytokines are secreted proteins that influence the survival, proliferation, and differentiation of immune cells and other organ systems. Cytokines function as intracellular signals and almost all cells in the body either secrete them or have cytokine receptors. Thus, understanding cytokine role in a specific physiological situation such as a bout of RT can be exceedingly complex. The overall effect of long term RT appears to ameliorate inflammation, but the specific effects on the inflammatory cytokine, tumor necrosis factor alpha are not clear, requiring further research. Furthermore, it is critical to differentiate between chronically and acute Interleukin-6 levels and its sources. The intensity of the RT and the characteristics of the training protocol may exert singular cytokine responses and as a result different adaptations to exercise. More research is needed in the area of RT in healthy populations, specifically sorting out gender and age RT acute responses. More importantly, studies are needed in obese individuals who are at high risk of developing low grade systemic inflammatory related diseases. Assuring adherence to the RT program is essential to get the benefits after overcoming the first acute RT responses. Hence RT could be an effective way to prevent, and delay low grade systemic inflammatory related diseases.

The Pro- and Anti-Inflammatory Cytokine Response to Exercise in Adolescent Swimmers

OBJECTIVE

Whether or not individuals with allergy and asthma experience different patterns of change in the balance of both pro- and anti-inflammatory mediators with acute exercise is not known. We hypothesized that adolescent swimmers with a clinical diagnosis of respiratory allergy would have an exaggerated proinflammatory response to laboratory exercise relative to a no-allergy comparison group.

METHODS

Adolescent swimmers (17 with clinical symptoms of respiratory allergy (CSRA) and 17 in comparison group) completed the American Thoracic Society (ATS) exercise challenge on cycle ergometer. Blood was collected at baseline and immediately post-exercise. All study tests were conducted at the Institute for Clinical Translational Science at the University of California, Irvine. Circulating cytokines, growth factors, and adhesion molecules were measured using ELISAs including transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), IL-6, IL-10, P-selectin, and immunoglobulin E (IgE).

RESULTS

There was a trend toward higher resting levels of TNF-α in the CSRA group (P = 0.076). Exercise induced a significant increase in P-selectin and TGF-β1 in both groups. TNF-α increased significantly (17%) in the comparison group (pre = 0.6, post = 0.7 pg/mL), but not in the CSRA group. IL-6 increased significantly in the CSRA group (pre = 0.7, post = 0.8 pg/mL), but not in the comparison group. Circulating levels of IL-4 and IL-10 were not altered immediately post-exercise in either group.

CONCLUSIONS

A short bout of intense exercise increased inflammatory growth factors and adhesion molecules, namely TGF-β1 and P-selectin, both of which are known to be involved in allergic airway diseases. Differences in resting IL-6 and TNF-α and exercise alterations in these cytokines may also contribute to allergic disease in adolescent elite swimmers.