Debunking the Myth of Exercise-Induced Immune Suppression: Redefining the Impact of Exercise on Immunological Health Across the Lifespan

Low energy availability increases immune cell formation of reactive oxygen species and impairs exercise performance in female endurance athletes

INTRODUCTION

The effects of low energy availability (LEA) on the immune system are poorly understood. This study examined the effects of 14 days of LEA on immune cell redox balance and inflammation at rest and in response to acute exercise, and exercise performance in female athletes.

METHODS

Twelve female endurance athletes (age: 26.8 ± 3.4 yrs, maximum oxygen uptake (V˙O2max): 55.2 ± 5.1 mL × min-1 × kg-1) were included in a randomized, single-blinded crossover study. They were allocated to begin with either 14 days of optimal energy availability diet (OEA, 52 ± 2 kcal × kg fat free mass (FFM)-1 × day-1) or LEA diet (22 ± 2 kcal × kg FFM-1 × day-1), followed by 3 days of refueling (OEA) with maintained training volume. Peripheral blood mononuclear cells (PBMCs) were isolated, and plasma obtained at rest before and after each dietary period. The PBMCs were used for analysis of mitochondrial respiration and H2O2 emission and specific proteins. Exercise performance was assessed on cycle by a 20-min time trial and time to exhaustion at an intensity corresponding to ∼110 % V˙O2max).

RESULTS

LEA was associated with a 94 % (P = 0.003) increase in PBMC NADPH oxidase 2 protein content, and a 22 % (P = 0.013) increase in systemic cortisol. LEA also caused an alteration of several inflammatory related proteins (P < 0.05). Acute exercise augmented H2O2 emission in PBMCs (P < 0.001) following both OEA and LEA, but to a greater extent following LEA. LEA also reduced the mobilization of white blood cells with acute exercise. After LEA, performance was reduced in both exercise tests (P < 0.001), and the reduced time trial performance remained after the 3 days of refueling (P < 0.001).

CONCLUSION

14 days of LEA in female athletes increased cortisol levels and had a pronounced effect on the immune system, including increased capacity for ROS production, altered plasma inflammatory proteome and lowered exercise induced mobilization of leukocytes. Furthermore, LEA resulted in a sustained impairment in exercise performance.

Molecular adaptations in response to exercise training are associated with tissue-specific transcriptomic and epigenomic signatures

Regular exercise has many physical and brain health benefits, yet the molecular mechanisms mediating exercise effects across tissues remain poorly understood. Here we analyzed 400 high-quality DNA methylation, ATAC-seq, and RNA-seq datasets from eight tissues from control and endurance exercise-trained (EET) rats. Integration of baseline datasets mapped the gene location dependence of epigenetic control features and identified differing regulatory landscapes in each tissue. The transcriptional responses to 8 weeks of EET showed little overlap across tissues and predominantly comprised tissue-type enriched genes. We identified sex differences in the transcriptomic and epigenomic changes induced by EET. However, the sex-biased gene responses were linked to shared signaling pathways. We found that many G protein-coupled receptor-encoding genes are regulated by EET, suggesting a role for these receptors in mediating the molecular adaptations to training across tissues. Our findings provide new insights into the mechanisms underlying EET-induced health benefits across organs.

Unraveling the link between cardiorespiratory fitness and cancer: a state-of-the-art review

Cardiorespiratory fitness (CRF) not only reflects an individual's capacity to perform physical activities but also encapsulates broader effects on the basic biology of aging. This review aims to summarize the evidence on the influence of CRF on overall and site-specific cancer risks. It delves into the biological mechanisms through which CRF may exert its effects, explores the clinical implications of these findings, identifies gaps in the current evidence base, and suggests directions for future research. The synthesis of findings reveals that higher CRF levels (general threshold of > 7 METs) are consistently associated with a reduced risk of a range of cancers, including head and neck, lung, breast, gastrointestinal, particularly pancreatic and colorectal, bladder, overall cancer incidence and mortality, and potentially stomach and liver, bile duct, and gall bladder cancers. These inverse associations between CRF and cancer risk do not generally differ across age groups, sex, race, or adiposity, suggesting a universal protective effect of CRF. Nonetheless, evidence linking CRF with skin, mouth and pharynx, kidney, and endometrial cancers is limited and inconclusive. Conversely, higher CRF levels may be potentially linked to an increased risk of prostate cancer and hematological malignancies, such as leukemia and myeloma, although the evidence is still not conclusive. CRF appears to play a significant role in reducing the risk of several cancers through various biological mechanisms, including inflammation reduction, immune system enhancement, hormonal regulation, and metabolic improvements. Overall, enhancing CRF through regular physical activity offers a vital, accessible strategy for reducing cancer risk and extending the health span. Future research should aim to fill the existing evidence gaps regarding specific cancers and elucidate the detailed dose-response relationships between CRF levels and cancer risk. Studies are also needed to elucidate the causal relationships and mechanistic pathways linking CRF to cancer outcomes.

Freshwater sports and infectious diseases: A narrative review

Freshwater sports involve a wide range of practices leading to contact with soil and water that can entail exposure to agents of potential infectious diseases. The pathogens can be multiple (bacteria, parasites, viruses, fungi), and be either well-known or more unfamiliar and exotic. We conducted a literature review to describe various infections contracted following exposure to water and mud during freshwater sport activities. Out of the 1011 articles identified, 50 were finally included. Our findings encompassed bacterial infections (leptospirosis and gastrointestinal infections); parasitic infections (schistosomiasis, cercarial dermatitis); viral infections (norovirus and other gastrointestinal viruses; seaweed contamination; and fungal infections. These infections were reported in various countries worldwide among diverse freshwater sport activities, including swimming, surfing, kayaking, as well as extreme sports such as adventure races and mud runs. Water sports in freshwater can expose participants to infectious risks according to geographical location and type of sport. Because regular sport practice is beneficial for health, freshwater sports should not be avoided due to potential exposure to pathogens; that much said, certain precautions should be taken. In addition to adoption of preventive measures, participants should be informed about infectious risks and seek medical advice if symptoms appear after exposure. Current guidelines for assessment of bathing water quality do not suffice to ensure comprehensive evaluation of freshwater quality. Event organizers are called upon to pay close attention to environmental factors and meteorological events, to conduct timely sensitization campaigns, and to enforce appropriate safety measures.

Comparison of Australian Football League Women's athletes match day energy and nutrient intake to recommendations

AIMS

This cross-sectional observational study quantified Australian Football League Women's athletes' match volume, and compared match-day dietary intakes against recommendations.

METHODS

Self-report, direct observation, and fluid measurements determined dietary intake (n = 17, 25 ± 4.5 years, 22.8 ± 1.8 kg/m2) on five home match days (early or late starting). Global positioning system software captured match volume. Linear mixed effects models evaluated differences in early versus late match volume and nutrient intakes. Data are presented as mean ± standard deviation.

RESULTS

Athletes covered 6712 ± 622 m during matches, with similar numbers of very high-intensity running efforts over equal distances in early and late matches (early vs. late efforts [no.]: 8.5 ± 4.9 vs. 9.5 ± 5.5; distance [m]: 203 ± 127 vs. 212 ± 113). Across all match days, 71% (n = 12) of athletes met their predicted daily energy requirements. However, 82% (n = 14) failed to meet minimum daily carbohydrate recommendations; intake was lower on early compared with late match days (4.7 g/day vs. 5.4 g/kg/day, p = 0.027). On average, no athletes met carbohydrate recommendations in the 2 h prior to a match and only 24% (n = 4) met recommendations during matches. All athletes met post-match carbohydrate and protein requirements.

CONCLUSION

Athletes cover large distances during games with frequent bursts of high-intensity running. However, they do not adjust their intake to meet the energy demands of competition, with inadequate fuelling prior to and during matches. These findings emphasise the need for greater athlete education and dietary support to maximise strategic fuelling to optimise athletic performance.

Sports and Immunity, from the recreational to the elite athlete

The pivotal role of the immune system in physical activity is well-established. While interactions are complex, they tend to constitute discrete immune responses. Moderate intensity exercise causes leukocytosis with a mild anti-inflammatory cytokine profile and immunoenhancement. Above a threshold of intensity, lactate-mediated IL-6 release causes a proinflammatory state followed by a depressed inflammatory state, which stimulates immune adaptation and longer term cardiometabolic enhancement. Exercise-related immune responses are modulated by sex, age and immunonutrition. At all ability levels, these factors collectively affect the immune balance between enhancement or overload and dysfunction. Excessive training, mental stress or insufficient recovery risks immune cell exhaustion and hypothalamic pituitary axis (HPA) stress responses causing immunodepression with negative impacts on performance or general health. Participation in sport provides additional immune benefits in terms of ensuring regularity, social inclusion, mental well-being and healthier life choices in terms of diet and reduced smoking and alcohol, thereby consolidating healthy lifestyles and longer term health. Significant differences exist between recreational and professional athletes in terms of inherent characteristics, training resilience and additional stresses arising from competition schedules, travel-related infections and stress. Exercise immunology examines the central role of immunity in exercise physiology and straddles multiple disciplines ranging from neuroendocrinology to nutrition and genetics, with the aim of guiding athletes to train optimally and safely. This review provides a brief outline of the main interactions of immunity and exercise, some influencing factors, and current guidance on maintaining immune health.

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.

Exercise activates interferon response of the liver via Gpld1 to enhance antiviral innate immunity

Healthy behavioral patterns could modulate organ functions to enhance the body's immunity. However, how exercise regulates antiviral innate immunity remains elusive. Here, we found that exercise promotes type I interferon (IFN-I) production in the liver and enhances IFN-I immune activity of the body. Despite the possibility that many exercise-induced factors could affect IFN-I production, we identified Gpld1 as a crucial molecule, and the liver as the major organ to promote IFN-I production after exercise. Exercise largely loses the efficiency to induce IFN-I in Gpld1-/- mice. Further studies demonstrated that exercise-produced 3-hydroxybutanoic acid (3-HB) critically induces Gpld1 expression in the liver. Gpld1 blocks the PP2A-IRF3 interaction, thus enhancing IRF3 activation and IFN-I production, and eventually improving the body's antiviral ability. This study reveals that exercise improves antiviral innate immunity by linking the liver metabolism to systemic IFN-I activity and uncovers an unknown function of liver cells in innate immunity.

Exercise to Prevent Accelerated Vascular Aging in People Living With HIV

Given advances in antiretroviral therapy, the mortality rate for HIV infection has dropped considerably over recent decades. However, people living with HIV (PLWH) experience longer life spans coupled with persistent immune activation despite viral suppression and potential toxicity from long-term antiretroviral therapy use. Consequently, PLWH face a cardiovascular disease (CVD) risk more than twice that of the general population, making it the leading cause of death among this group. Here, we briefly review the epidemiology of CVD in PLWH highlighting disparities at the intersections of sex and gender, age, race/ethnicity, and the contributions of social determinants of health and psychosocial stress to increased CVD risk among individuals with marginalized identities. We then overview the pathophysiology of HIV and discuss the primary factors implicated as contributors to CVD risk among PLWH on antiretroviral therapy. Subsequently, we highlight the functional evidence of premature vascular dysfunction as an early pathophysiological determinant of CVD risk among PLWH, discuss several mechanisms underlying premature vascular dysfunction in PLWH, and synthesize current research on the pathophysiological mechanisms underlying accelerated vascular aging in PLWH, focusing on immune activation, chronic inflammation, and oxidative stress. We consider understudied aspects such as HIV-related changes to the gut microbiome and psychosocial stress, which may serve as mechanisms through which exercise can abrogate accelerated vascular aging. Emphasizing the significance of exercise, we review various modalities and their impacts on vascular health, proposing a holistic approach to managing CVD risks in PLWH. The discussion extends to critical future study areas related to vascular aging, CVD, and the efficacy of exercise interventions, with a call for more inclusive research that considers the diversity of the PLWH population.

Immunology of Physical Exercise: Is Equus caballus an Appropriate Animal Model for Human Athletes?

Domestic horses routinely participate in vigorous and various athletic activities. This enables the horse to serve as a model for studying athletic physiology and immunology in other species, including humans. For instance, as a model of physical efforts, such as endurance rides (long-distance running/aerobic exercise) and races (anaerobic exercise), the horse can be useful in evaluating post-exercise response. Currently, there has been significant interest in finding biomarkers, which characterize the advancement of training and adaptation to physical exercise in the horse. The parallels in cellular responses to physical exercises, such as changes in receptor expression and blood cell activity, improve our understanding of the mechanisms involved in the body's response to intense physical activity. This study focuses on the changes in levels of the pro- and anti-inflammatory cytokines and cellular response in the context of post-exercise immune response. Both the direction of changes in cytokine levels and cellular responses of the body, such as proliferation and expression of surface markers on lymphocytes, monocytes and neutrophils, show cross-functional similarities. This review reveals that horses are robust research models for studying the immune response to physical exercise in human athletes.

Metabolic pathways in immune senescence and inflammaging: Novel therapeutic strategy for chronic inflammatory lung diseases. An EAACI position paper from the Task Force for Immunopharmacology

The accumulation of senescent cells drives inflammaging and increases morbidity of chronic inflammatory lung diseases. Immune responses are built upon dynamic changes in cell metabolism that supply energy and substrates for cell proliferation, differentiation, and activation. Metabolic changes imposed by environmental stress and inflammation on immune cells and tissue microenvironment are thus chiefly involved in the pathophysiology of allergic and other immune-driven diseases. Altered cell metabolism is also a hallmark of cell senescence, a condition characterized by loss of proliferative activity in cells that remain metabolically active. Accelerated senescence can be triggered by acute or chronic stress and inflammatory responses. In contrast, replicative senescence occurs as part of the physiological aging process and has protective roles in cancer surveillance and wound healing. Importantly, cell senescence can also change or hamper response to diverse therapeutic treatments. Understanding the metabolic pathways of senescence in immune and structural cells is therefore critical to detect, prevent, or revert detrimental aspects of senescence-related immunopathology, by developing specific diagnostics and targeted therapies. In this paper, we review the main changes and metabolic alterations occurring in senescent immune cells (macrophages, B cells, T cells). Subsequently, we present the metabolic footprints described in translational studies in patients with chronic asthma and chronic obstructive pulmonary disease (COPD), and review the ongoing preclinical studies and clinical trials of therapeutic approaches aiming at targeting metabolic pathways to antagonize pathological senescence. Because this is a recently emerging field in allergy and clinical immunology, a better understanding of the metabolic profile of the complex landscape of cell senescence is needed. The progress achieved so far is already providing opportunities for new therapies, as well as for strategies aimed at disease prevention and supporting healthy aging.

Impact of exercise on markers of B cell-related immunity: A systematic review

BACKGROUND

B cells represent a crucial component of adaptive immunity that ensures long-term protection from infection by generating pathogen-specific immunoglobulins. Exercise alters B cell counts and immunoglobulin levels, but evidence-based conclusions on potential benefits for adaptive immunity are lacking. This systematic review assessed current literatures on the impact of acute exercise and exercise training on B cells, immunoglobulins, and markers of secretory immunity in human biofluids.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, MEDLINE, Web of Science, and Embase were searched on March 8, 2023. Non-randomized controlled trials and crossover trials investigating the impact of acute exercise or exercise training on B cell counts and proportions, immunoglobulin levels, salivary flow rate, or secretory immunoglobulin A secretion rate were included. Quality and reporting of exercise training studies were assessed using the Tool for the Assessment of Study Quality and reporting in Exercise. Study characteristics, outcome measures, and statistically significant changes were summarized tabularly.

RESULTS

Of the 67 eligible studies, 22 applied acute exercise and 45 applied exercise training. All included outcomes revealed significant alterations over time in acute exercise and exercise training context, but only a few investigations showed significant differences compared to control conditions. Secretory and plasma immunoglobulin A levels were most consistently increased in response to exercise training.

CONCLUSION

B cell-related outcomes are altered by acute exercise and exercise training, but evidence-based conclusions cannot be drawn with high confidence due to the large heterogeneity in populations and exercise modalities. Well-designed trials with large sample sizes are needed to clarify how exercise shapes B cell-related immunity.

Immune consequences of exercise in hypoxia: A narrative review

Immune outcomes are key mediators of many health benefits of exercise and are determined by exercise type, dose (frequency/duration, intensity), and individual characteristics. Similarly, reduced availability of ambient oxygen (hypoxia) modulates immune functions depending on the hypoxic dose and the individual capacity to respond to hypoxia. How combined exercise and hypoxia (e.g., high-altitude training) sculpts immune responses is not well understood, although such combinations are becoming increasingly popular. Therefore, in this paper, we summarize the impact on immune responses of exercise and of hypoxia, both independently and together, with a focus on specialized cells in the innate and adaptive immune system. We review the regulation of the immune system by tissue oxygen levels and the overlapping and distinct immune responses related to exercise and hypoxia, then we discuss how they may be modulated by nutritional strategies. Mitochondrial, antioxidant, and anti-inflammatory mechanisms underlie many of the adaptations that can lead to improved cellular metabolism, resilience, and overall immune functions by regulating the survival, differentiation, activation, and migration of immune cells. This review shows that exercise and hypoxia can impair or complement/synergize with each other while regulating immune system functions. Appropriate acclimatization, training, and nutritional strategies can be used to avoid risks and tap into the synergistic potentials of the poorly studied immune consequences of exercising in a hypoxic state.

Exercise and osteoimmunology in bone remodeling

Bones can form the scaffolding of the body, support the organism, coordinate somatic movements, and control mineral homeostasis and hematopoiesis. The immune system plays immune supervisory, defensive, and regulatory roles in the organism, which mainly consists of immune organs (spleen, bone marrow, tonsils, lymph nodes, etc.), immune cells (granulocytes, platelets, lymphocytes, etc.), and immune molecules (immune factors, interferons, interleukins, tumor necrosis factors, etc.). Bone and the immune system have long been considered two distinct fields of study, and the bone marrow, as a shared microenvironment between the bone and the immune system, closely links the two. Osteoimmunology organically combines bone and the immune system, elucidates the role of the immune system in bone, and creatively emphasizes its interdisciplinary characteristics and the function of immune cells and factors in maintaining bone homeostasis, providing new perspectives for skeletal-related field research. In recent years, bone immunology has gradually become a hot spot in the study of bone-related diseases. As a new branch of immunology, bone immunology emphasizes that the immune system can directly or indirectly affect bones through the RANKL/RANK/OPG signaling pathway, IL family, TNF-α, TGF-β, and IFN-γ. These effects are of great significance for understanding inflammatory bone loss caused by various autoimmune or infectious diseases. In addition, as an external environment that plays an important role in immunity and bone, this study pays attention to the role of exercise-mediated bone immunity in bone reconstruction.

The Role of Diet and Physical Activity in Shaping COVID-19 Severity: Design, Validation, and Application of a Retrospective Questionnaire

After the global challenges posed by COVID-19, researchers strived to identify risk factors for severe cases, which lead to various complications-including death. Lifestyle modifications, such as implementing a healthy diet and recommended physical activity, have been shown to be protective against severe COVID-19 cases. Despite an association of a plant-based diet with reduced COVID-19 severity, specific dietary characteristics have not been identified. Also, the methodology for measuring physical activity is variable, with studies overlooking the intensity or the habit components of physical activity. To bridge this gap, our study designed, validated, and applied a retrospective questionnaire with aims of exploring the relationship between lifestyle factors, specifically diet and physical activity, and severe COVID-19. We considered the intensity and years of physical activity habit, which is a limitation of other questionnaires. Results reveal associations of age and BMI with severe COVID-19. An excessive sugar diet was found to be associated with severe COVID-19 and increased symptom duration. We also observed an inverse relationship pattern of moderate- and vigorous-intensity physical activity across case severity, which is absent in walking physical activity. This study lays a foundation for research aiming to identify lifestyle factors that prevent severe COVID-19 cases.

Early-life exercise induces immunometabolic epigenetic modification enhancing anti-inflammatory immunity in middle-aged male mice

Exercise is usually regarded to have short-term beneficial effects on immune health. Here we show that early-life regular exercise exerts long-term beneficial effects on inflammatory immunity. Swimming training for 3 months in male mice starting from 1-month-old curbs cytokine response and mitigates sepsis when exposed to lipopolysaccharide challenge, even after an 11-month interval of detraining. Metabolomics analysis of serum and liver identifies pipecolic acid, a non-encoded amino acid, as a pivotal metabolite responding to early-life regular exercise. Importantly, pipecolic acid reduces inflammatory cytokines in bone marrow-derived macrophages and alleviates sepsis via inhibiting mTOR complex 1 signaling. Moreover, early-life exercise increases histone 3 lysine 4 trimethylation at the promoter of Crym in the liver, an enzyme responsible for catalyzing pipecolic acid production. Liver-specific knockdown of Crym in adult mice abolishes this early exercise-induced protective effects. Our findings demonstrate that early-life regular exercise enhances anti-inflammatory immunity during middle-aged phase in male mice via epigenetic immunometabolic modulation, in which hepatic pipecolic acid production has a pivotal function.

The effect of physical exercise on anticancer immunity

Regular physical activity is associated with lower cancer incidence and mortality, as well as with a lower rate of tumour recurrence. The epidemiological evidence is supported by preclinical studies in animal models showing that regular exercise delays the progression of cancer, including highly aggressive malignancies. Although the mechanisms underlying the antitumorigenic effects of exercise remain to be defined, an improvement in cancer immunosurveillance is likely important, with different immune cell subtypes stimulated by exercise to infiltrate tumours. There is also evidence that immune cells from blood collected after an exercise bout could be used as adoptive cell therapy for cancer. In this Perspective, we address the importance of muscular activity for maintaining a healthy immune system and discuss the effects of a single bout of exercise (that is, 'acute' exercise) and those of 'regular' exercise (that is, repeated bouts) on anticancer immunity, including tumour infiltrates. We also address the postulated mechanisms and the clinical implications of this emerging area of research.

Higher level of physical activity reduces mental and neurological symptoms during and two years after COVID-19 infection in young women

Previous studies found that regular physical activity (PA) can lower the risk of SARS-CoV-2 (COVID-19) infection and post-COVID-19 condition (PCC), yet its specific effects in young women have not yet been investigated. Thus, we aimed to examine whether regular physical activity reduces the number of symptoms during and after COVID-19 infection among young women aged between 18 and 34 (N = 802), in which the confounding effect of other morbidities could be excluded. The average time since infection was 23.5 months. Participants were classified into low, moderate, and high PA categories based on the reported minutes per week of moderate and vigorous PA. Using the Post-COVID-19 Case Report Form, 50 different symptoms were assessed. Although regular PA did not decrease the prevalence of COVID-19 infection and PCC but significantly reduced the number of mental and neurological symptoms both in acute COVID-19 and PCC. Importantly, the high level of PA had a greater impact on health improvements. In addition, the rate of reinfection decreased with an increased level of PA. In conclusion, a higher level of regular PA can reduce the risk of reinfection and the number of mental and neurological symptoms in PCC underlying the importance of regular PA, even in this and likely other viral disease conditions.

HIIT Induces Stronger Shifts within the Peripheral T Cell Compartment Independent of Sex

Acute exercise induces changes within the T-cell compartment, especially in cytotoxic CD8+ memory subsets, depending on exercise intensity and duration. It is unclear whether exercise-induced changes in major T-cell subsets differ in response to acute high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) and whether sex-specific effects exist. Twenty-four recreationally active runners (females: n=12, 27.8±4.1years, 54.4±4.6 ml*kg-1*min-1; males: n=12, 31.6±3.8years, 58.9±7.7 ml*kg-1*min-1) participated in this randomized controlled crossover study, and conducted an energy- and duration-matched HIIT and MICT session. Blood was sampled before (T1), immediately (T2) and 1 h after exercise (T3). Flow cytometry was used to identify T-cell populations. HIIT decreased the proportion of CD8+ T-cells more pronounced at T3 compared to MICT (p=0.007), induced a significantly stronger increase in the CD8+ effector memory (TEM) cell proportion at T2 (p=0.032), and decreased CD4+ central memory proportion more pronounced at T2 (p=0.029). A decrease below baseline CD8+ TEM proportion at T3 was observed only after HIIT (p<0.001). No interaction effects between sexes were revealed. Taken together, HIIT represents a more potent stimulus to induce shifts mainly within the cytotoxic CD8+ T-cell compartment, thereby giving implications to investigate the role of HIIT on the cell´s effector phenotype and function in more detail.

Acute exercise-induced release of innate immune proteins via small extracellular vesicles changes with aerobic fitness and age

AIM

Physical exercise triggers the secretion of small extracellular vesicles (sEVs) into the circulation in humans, enabling signalling crosstalk between tissues. Exercise-derived EVs and their cargo have been proposed to mediate adaptations to exercise; however, our understanding of how exercise-derived EV protein cargo is modulated by factors such as aerobic fitness and age of an individual is currently unknown. Here, we examined the circulating sEV proteome following aerobic exercise in healthy males of different ages and aerobic fitness to understand exercise-induced EV response during the aging process.

METHODS

Twenty-eight healthy men completed a bout of 20-min cycling exercise at 70% estimated VO2peak . Small EVs were isolated from blood samples collected before and immediately after exercise, and then quantified using particle analysis and Western blotting. Small EV proteome was examined using quantitative proteomic analysis.

RESULTS

We identified a significant increase in 13 proteins in small plasma EVs following moderate-to-vigorous intensity exercise. We observed distinct changes in sEV proteome after exercise in young, mature, unfit, and fit individuals, highlighting the impact of aerobic fitness and age on sEV protein secretion. Functional enrichment and pathway analysis identified that the majority of the significantly altered sEV proteins are associated with the innate immune system, including proteins known to be damage-associated molecular patterns (DAMPs).

CONCLUSION

Together, our findings suggest that exercise-evoked acute stress can positively challenge the innate immune system through the release of signalling molecules such as DAMPs in sEVs, proposing a novel EV-based mechanism for moderate-to-vigorous intensity exercise in immune surveillance pathways.

The effects of short-term, progressive exercise training on disease activity in smouldering multiple myeloma and monoclonal gammopathy of undetermined significance: a single-arm pilot study

BACKGROUND

High levels of physical activity are associated with reduced risk of the blood cancer multiple myeloma (MM). MM is preceded by the asymptomatic stages of monoclonal gammopathy of undetermined significance (MGUS) and smouldering multiple myeloma (SMM) which are clinically managed by watchful waiting. A case study (N = 1) of a former elite athlete aged 44 years previously indicated that a multi-modal exercise programme reversed SMM disease activity. To build from this prior case study, the present pilot study firstly examined if short-term exercise training was feasible and safe for a group of MGUS and SMM patients, and secondly investigated the effects on MGUS/SMM disease activity.

METHODS

In this single-arm pilot study, N = 20 participants diagnosed with MGUS or SMM were allocated to receive a 16-week progressive exercise programme. Primary outcome measures were feasibility and safety. Secondary outcomes were pre- to post-exercise training changes to blood biomarkers of MGUS and SMM disease activity- monoclonal (M)-protein and free light chains (FLC)- plus cardiorespiratory and functional fitness, body composition, quality of life, blood immunophenotype, and blood biomarkers of inflammation.

RESULTS

Fifteen (3 MGUS and 12 SMM) participants completed the exercise programme. Adherence was 91 ± 11%. Compliance was 75 ± 25% overall, with a notable decline in compliance at intensities > 70% V̇O2PEAK. There were no serious adverse events. There were no changes to M-protein (0.0 ± 1.0 g/L, P =.903), involved FLC (+ 1.8 ± 16.8 mg/L, P =.839), or FLC difference (+ 0.2 ± 15.6 mg/L, P =.946) from pre- to post-exercise training. There were pre- to post-exercise training improvements to diastolic blood pressure (- 3 ± 5 mmHg, P =.033), sit-to-stand test performance (+ 5 ± 5 repetitions, P =.002), and energy/fatigue scores (+ 10 ± 15%, P =.026). Other secondary outcomes were unchanged.

CONCLUSIONS

A 16-week progressive exercise programme was feasible and safe, but did not reverse MGUS/SMM disease activity, contrasting a prior case study showing that five years of exercise training reversed SMM in a 44-year-old former athlete. Longer exercise interventions should be explored in a group of MGUS/SMM patients, with measurements of disease biomarkers, along with rates of disease progression (i.e., MGUS/SMM to MM).

REGISTRATION

https://www.isrctn.com/ISRCTN65527208 (14/05/2018).

Effect of histamine-receptor antagonism on the circulating inflammatory cell and cytokine response to exercise: A pilot study

The purpose of this study was to gain insight into histamine's role in the exercise inflammatory response and recovery from exercise. To explore this, young healthy participants (n = 12) performed 300 eccentric leg extensions under control (Placebo) versus histamine H1 and H2 receptor antagonism (Blockade) in a randomized cross-over study. Circulating leukocytes and cytokines were measured for 72 h after exercise. Circulating leukocytes were elevated at 6 and 12 h after exercise (p < 0.05) with the peak response being a 44.1 ± 11.7% increase with Blockade versus 13.7 ± 6.6% with Placebo (both p < 0.05 vs. baseline, but also p < 0.05 between Blockade and Placebo). Of the cytokines that were measured, only MCP-1 was elevated following exercise. The response at 6 h post-exercise was a 104.0 ± 72.5% increase with Blockade versus 93.1 ± 41.9% with Placebo (both p < 0.05 vs. baseline, p = 0.82 between Blockade and Placebo). The main findings of the present investigation were that taking combined histamine H1 and H2 receptor antagonists augmented the magnitude but not the duration of the increase of circulating immune cells following exercise. This suggests histamine is not only exerting a local influence within the skeletal muscle but that it may influence the systemic inflammatory patterns.

Physical exercise in kidney disease: A commonly undervalued treatment modality

BACKGROUND

Physical inactivity has been identified as a risk factor for multiple disorders and a strong association exists between chronic kidney disease (CKD) and a sedentary lifestyle. Even though physical activity is crucial in the development and progression of disease, the general focus of the current medical practice is the pharmacological perspective of diseases with inadequate emphasis on lifestyle intervention.

METHODS

In this narrative review we explain the pathophysiological mechanisms underlying the beneficial effects of physical exercise on CKD in addition to discussing the clinical studies and trials centred on physical exercise in patients with CKD.

RESULTS

Physical activity influences several pathophysiological mechanisms including inflammation, oxidative stress, vascular function, immune response and macromolecular metabolism. While exercise can initially induce stress responses like inflammation and oxidative stress, long-term physical activity leads to protective countermeasures and overall improved health. Trials in pre-dialysis CKD patients show that exercise can lead to reductions in body weight, inflammation markers and fasting plasma glucose. Furthermore, it improves patients' functional capacity, cardiorespiratory fitness and quality of life. The effects of exercise on kidney function have been inconsistent in these trials. In haemodialysis, peritoneal dialysis and kidney transplant patients exercise interventions improve cardiorespiratory fitness, walking capacity and quality of life. Combined training shows the best performance to increase peak oxygen uptake in haemodialysis patients. In kidney transplant recipients, exercise improves walking performance, quality of life and potentially arterial stiffness. However, exercise does not affect glucose metabolism, serum cholesterol and inflammation biomarkers. Long-term, adequately powered trials are needed to determine the long-term feasibility, and effects on quality of life and major clinical outcomes, including mortality and cardiovascular risk, in all CKD stages and particularly in kidney transplant patients, a scarcely investigated population.

CONCLUSION

Physical exercise plays a crucial role in ameliorating inflammation, oxidative stress, vascular function, immune response and macromolecular metabolism, and contributes significantly to the quality of life for patients with CKD, irrespective of the treatment and stage. Its direct impact on kidney function remains uncertain. Further extensive, long-term trials to conclusively determine the effect of exercise on major clinical outcomes such as mortality and cardiovascular risk remain a research priority.

The acute effects of pre- and mid-exercise carbohydrate ingestion on the immunoregulatory stress hormone release in experienced endurance athletes-a systematic review

Background

In times of physical stress, the body orchestrates a multisystemic regulatory response. The hormones epinephrine and norepinephrine play a role in the immediate regulation chain, while cortisol is involved in delayed regulation. The release of those stress hormones in response to exercise has previously been reported to elicit diverse immune reactions.

Objective

The aim of this systematic review was to examine and present the acute effects of immediate pre- and mid-exercise carbohydrate ingestion on cortisol, epinephrine and norepinephrine levels in experienced endurance athletes.

Methods

A systematic literature search was conducted using PubMed, Cochrane Library and Web of Science in accordance with PRISMA guidelines up to February 2023. Randomized controlled trials in English or German language were included if baseline and at least two follow-up measures of blood plasma or serum of chosen stress hormones (cortisol, epinephrine, norepinephrine) were collected in response to prolonged continuous endurance activity. Eligibility furthermore required an acute carbohydrate ingestion of at least 30 g of carbohydrates per hour no more than 30 min before start of the exercise, as well as a placebo-controlled study design.

Results

Eleven studies of moderate to high quality were included in this review. Carbohydrate ingestion of at least 30 g per hour was able to attenuate rises in cortisol concentration in majority of the included studies. Epinephrine levels were considerably lower with ingestion of carbohydrates compared to placebo in all studies. Norepinephrine concentrations were largely unaffected by acute carbohydrate feeding.

Conclusion

Pre- and mid-exercise ingestion of carbohydrates seems an effective dietary strategy to attenuate rises in cortisol and epinephrine levels and, thus, an effective countermeasure for endurance exercise-induced increases in stress hormone levels.

Complement System Deficiencies in Elite Athletes

BACKGROUND

Although regular physical activity improves immune competency and reduces the prevalence of inflammatory diseases, strenuous training in elite athletes is associated with an increased susceptibility to infectious complications. Therefore, the objective of our study was to assess the routinely examined parameters of the complement system in elite athletes. The study was carried out in a cohort of elite athletes (n = 134) and healthy control subjects (n = 110). In all subjects, besides a routine laboratory check-up, serum concentrations of the C3 and C4 complement components, mannose-binding lectin (MBL), as well as activation of all three complement pathways were determined.

RESULTS

Compared to healthy controls, lower C3 and C4 complement component concentrations were observed in elite athletes (0.96 ± 0.1 vs. 1.08 ± 0.2 mg/L, and 0.18 ± 0.1 vs. 0.25 ± 0.1 mg/L, respectively, p < 0.05); with much higher frequency rates of C3 and C4 deficiencies in athletes (31.3 vs. 14.5%, and 6 vs. 0%, p < 0.05). Simultaneously, athletes had much higher frequency rates of deficiencies of activation of classical and alternative complement pathways; while, deficiency of activation of the lectin pathway was similar in both cohorts.

CONCLUSIONS

We confirmed a high frequency of defects in the complement system in elite athletes. Lower concentrations of C3 and C4 complement components, with high frequencies of deficiencies of the classical and alternative complement activation pathways were the most prevalent disorder of the complement system in elite athletes. Further studies are needed to uncover the functional impacts of these observations upon the susceptibility to infectious diseases.

Immunomodulatory effects of exercise in cancer prevention and adjuvant therapy: a narrative review

Successful application of cancer immunotherapy has rekindled hope in cancer patients. However, a number of patients are unresponsive to immunotherapy and related treatments. This unresponsiveness in cancer patients toward different treatment regimens can be mainly attributed to severe immune dysfunction in such patients. Several reports indicate that physical exercise can significantly lead to improved cancer patient outcomes. Since exercise gets immense response from the immune system, it can be utilized to improve immune function. Leukocytes with enhanced functions are substantially mobilized into the circulation by a single bout of intense physical exercise. Chronic physical exercise results in greater muscle endurance and strength and improved cardiorespiratory function. This exercise regime is also useful in improving T-cell abundance and reducing dysfunctional T cells. The current available data strongly justify for future clinical trials to investigate physical exercise use as an adjuvant in cancer therapy; however, optimal parameters using exercise for a defined outcome are yet to be established. The components of the immune system associate with almost every tumorigenesis step. The inter-relationship between inflammation, cancer, and innate immunity has recently gained acceptance; however, the underlying cellular and molecular mechanisms behind this relationship are yet to be solved. Several studies suggest physical exercise-mediated induction of immune cells to elicit anti-tumorigenic effects. This indicates the potential of exercising in modulating the behavior of immune cells to inhibit tumor progression. However, further mechanistic details behind physical exercise-driven immunomodulation and anticancer effects have to be determined. This review aims to summarize and discuss the association between physical exercise and immune function modulation and the potential of exercise as an adjuvant therapy in cancer prevention and treatment.

Exercise to transform tumours from cold to hot and improve immunotherapy responsiveness

Exercise provides significant health benefits to patients diagnosed with cancer including improved survival outcomes, quality of life and reduced cancer recurrence. Across multiple murine cancer models, aerobic exercise and resistance training has exhibited anti-tumour properties illustrated by inhibited tumour growth, reduced metastatic potential and modulation of the tumour microenvironment to allow the recognition and destruction of cancer cells. Clinical studies have demonstrated the rapid mobilisation and circulatory release of mature lymphoid populations, myokines and cytokines that occurs with exercise along with tumour vasculature normalisation. Tumour microenvironments enriched with immune cells with anti-cancer potential, such as CD8+ T cells, are termed 'hot', whilst those favouring an immunosuppressive environment and lacking in effector immune cells are classed as 'cold'. Pre-clinical evidence suggests exercise training has the potential to reprogramme cold tumours to become hot, although this requires validation in clinical studies. This hot environment could potentiate immunotherapy responsiveness, improving survival outcomes of patients undergoing cancer immunotherapy and allow those with typically cold tumours to benefit from immunotherapy. This review discusses the complex interactions between exercise and cancer, including exercise-induced alterations within the tumour microenvironment and systemic immunity. The potential role exercise may play in improving cancer immunotherapy responsiveness is explored. This review also highlights the need for translational studies exploring the role of exercise in patients with cancer with the potential to widen the spectrum of tumours that derive significant benefit from immunotherapy.

The Impact of COVID-19 Health and Safety Measures on the Self-Reported Exercise Behaviors and Mental Health of College Students

The public-health restrictions (e.g., remote learning, restricted access to facilities and dining halls) put in place by colleges to reduce the spread of COVID-19 resulted in forced isolation and modifications to health-related behaviors. The restrictions and uncertainty associated with COVID-19 may have exacerbated the challenges of meeting exercise recommendations and mental-health concerns. The purpose of this study was to assess the impact of restrictions on students' exercise habits and their levels of anxiety, stress, and depression. Five-hundred and forty students completed a 29-question survey on individual demographics, living arrangements, exercise, sleep, diet, and mental health. Significant changes in weekly days of exercise and intensity were reported. Increases in anxiety, stress, and depression were reported. The two most frequently reported changes in exercise behavior were an increase in minutes of aerobic training (5%) and a combination of reduced minutes of aerobic and resistance training (3.9%), which could be reflective of an individual's ability and/or desire to maintain exercise behavior during the restrictions. Alternatively, for those students who reduced their exercise habits, aerobic training (11%) was the mode that suffered the most. Demographic factors such as ethnicity, regional residence, and gender were found to have significant effects on stress, anxiety, and depression. Amidst pandemics and future health emergencies, colleges should prioritize establishing opportunities for students to exercise, helping them meet physical activity recommendations and combat mental-health issues.

Vital role for primary healthcare providers: urgent need to educate the community about daily nutritional self-care to support immune function and maintain health

The importance of self-care to improve health and social well-being is well recognised. Nevertheless, there remains a need to encourage people to better understand how their body works, and how to keep it healthy. Because of its important role, part of this understanding should be based on why the immune system must be supported. This highly complex system is essential for defending against pathogens, but also for maintaining health throughout the body by preserving homeostasis and integrity. Accordingly, the immune system requires active management for optimal functioning and to reduce the risk of chronic diseases. In addition to regular exercise, healthy sleeping patterns, cultivating mental resilience, adequate nutrition through healthy and diverse dietary habits is key to the daily support of immune function. Diet and the immune system are closely intertwined, and a poor diet will impair immunity and increase the risk of acute and chronic diseases. To help elucidate the roles of primary healthcare providers in supporting individuals to engage in self-care, an international group of experts reviewed the evidence for the roles of the immune system in maintaining health and for nutrition in daily immune support, and discussed implications for population health and clinical practice.

Salivary concentrations of secretory leukocyte protease inhibitor and matrix metallopeptidase-9 following a single bout of exercise are associated with intensity and hydration status

AIM

To investigate the effects of exercise on salivary concentrations of inflammatory markers by analyzing a panel of 25 inflammatory markers in subjects who had participated in bicycle ergometer tests varying in workload and hydration status.

METHODS

Fifteen healthy young men (20-35 years) had performed 4 different exercise protocols of 1 hour duration in a randomly assigned cross-over design, preceded by a rest protocol. Individual workloads depended on participant's pre-assessed individual maximum workload (Wmax): rest (protocol 1), 70% Wmax in hydrated (protocol 2) and dehydrated (protocol 3) state, 50% Wmax (protocol 4) and intermittent 85%/55% Wmax in 2 min blocks (protocol 5). Saliva samples were collected before (T0) and immediately after exercise (T1), and at several time points after exercise (2 hours (T3), 3 hours (T4), 6 hours (T5) and 24 hours (T6)). Secretory Leukocyte Protease Inhibitor (SLPI), Matrix Metallopeptidase-9 (MMP-9) and lactoferrin was analyzed using a commercial ELISA kit, a panel of 22 cytokines and chemokines were analyzed using a commercial multiplex immunoassay. Data was analyzed using a multilevel mixed linear model, with multiple test correction.

RESULTS

Among a panel of 25 inflammatory markers, SLPI concentrations were significantly elevated immediately after exercise in all protocols compared to rest and higher concentrations reflected the intensity of exercise and hydration status. MMP-9 showed a significant increase in the 70% Wmax dehydrated, 50% Wmax and intermittent protocols.

CONCLUSIONS

Salivary concentrations of SLPI and MMP-9 seem associated with exercise intensity and hydration status and may offer non-invasive biomarkers to study (local) inflammatory responses to different exercise intensities in human studies.

Team USA injury and illness incidence at the 2022 Beijing Winter Olympic and Paralympic Games

OBJECTIVE

The purpose of this study was to determine the injury and illness incidence from Team USA athletes from the 2022 Beijing Winter Olympic and Paralympic Games and assess any sex-based differences or differences between Olympic and Paralympic athletes.

METHODS

Team USA Olympic (n=231, 48.5% female) and Team USA Paralympic (n=63, 22.2% female) athletes had medical encounters documented during the Games. Injuries and illnesses were defined according to the 2020 International Olympic Committee Consensus Statement and reviewed for accuracy by a physician. Incidence rates were calculated per 1000 athlete-days and further analysed by sex, sport, anatomical location, type of illness, injury event and injury mechanism, with incident rate ratios (IRRs) used for group comparisons.

RESULTS

There were no differences in illness (Olympic illness, IRR=0.99 (95% CI 0.48 to 2.07), p=0.998; Paralympic illness, IRR=1.43 (95% CI 0.41 to 4.97), p=0.572) or injury rates (Olympic injury, IRR=0.63 (95% CI 0.39 to 1.03), p=0.062; Paralympic injury, IRR=1.01 (95% CI 0.43 to 2.35), p=0.988) between male and female (reference group) athletes. However, Olympic athletes had significantly lower illness (IRR=0.41 (95% CI 0.22 to 0.76), p=0.003) and injury (IRR=0.56 (95% CI 0.37 to 0.87), p=0.009) risks compared with Paralympic athletes.

CONCLUSION

No significant sex-related differences in injury or illness were detected in Team USA Olympic or Paralympic participating in the 2022 Beijing Winter Games. However, Paralympic athletes exhibited higher rates of injury and illness compared with their Olympic counterparts. This study highlights delegation-specific epidemiological data which may facilitate more focused approaches for injury and illness prevention.

The Effect of Acute Physical Exercise on Natural Killer Cells Populations and Cytokine Levels in Healthy Women

Physical exercise generates a systemic response in the immune system. It has been observed that cell populations respond to exercise stimuli, especially Natural Killer cells, whose number increase within minutes of starting physical exertion. This study aimed to evaluate the acute effect of moderate- and high-intensity exercise on immunological markers in healthy women. As specific objectives, the percentages of CD3-CD56+ Natural Killer total cells, CD56brightCD16dim effector subpopulation, CD56dimCD16bright cytotoxic subpopulation, NKG2A inhibition receptor, NKG2D activation receptor, and NKT cells were analyzed. In addition, the levels of the cytokines IL-1β, IL-6, IL-8, IL-10, IL-12p70, and TNF and the chemokines CCL5/RANTES, CXCL9/MIG, CCL2/MCP-1, and CXCL10/IP-10 were also analyzed. Natural Killer total cells showed an increase in their percentage in both exercise protocols (p = 0.001 for the moderate-intensity group and p = 0.023 for the high-intensity group); however, only in the high-intensity exercise session was there an increase in the CD56dimCD16bright cytotoxic subpopulation (p = 0.014), as well as a decrease in CD56brightCD16dim effector subpopulation (p = 0.001) and their NKG2A inhibition receptor (p = 0.043). An increase in IL-6 was observed after the high-intensity exercise session (p = 0.025). Conclusions. Physical exercise influences immunological markers and shows an acute response to moderate- or high-intensity exercise.

Short-term swimming up-regulates pro-inflammatory mediators and cytokines in gilthead seabream (Sparus aurata)

Aerobic swimming exercise in fish has been shown to improve robustness of some species. However, the optimal conditions to be applied and the mechanisms underlying remain unknown. We investigated the effects of 6 h of induced swimming on the immune response of gilthead seabream (Sparus aurata), by analysing markers related to immune status in plasma, skin mucus, gills, heart and head-kidney. Forty fish were individually exercised in swim tunnels by applying different water currents: steady low (SL, 0.8 body lengths (BL) s-1), steady high (SH, 2.3 BL s-1), oscillating low (OL, 0.2/0.8 BL s-1) and oscillating high (OH, 0.8/2.3 BL s-1) velocities, including a non-exercised group with minimal water flow (MF, <0.1 BL s-1). Swimming conditions did not trigger a stress response or anaerobic metabolism, suggested by similar levels of cortisol, lactate, and glucose in plasma among groups. Blood haemoglobin and innate immune parameters in plasma and skin mucus also remained unaltered. However, decreased blood haematocrit was observed in fish swimming on the OL condition. Interestingly, gene expression analysis revealed that the OL condition led to the up-regulation of pro-inflammatory mediators (nfκb1 and mapk3) and cytokines (tnfα, il1β and il6) in gills. A similar response occurred in heart, with an up-regulation of nfκb1, tnfα, il6 and cox2 in the OL condition. Gene expression of these cytokines was unaltered in the head-kidney. The inflammatory response in gills and heart of gilthead seabream triggered by the OL condition highlights the importance of establishing suitable rearing conditions to improve welfare of cultured fish.

Tracking Biomarker Responses to Exercise in Hypertension

PURPOSE OF REVIEW

Strong evidence is evolving that physical exercise prevents hypertension and reduces blood pressure in patients with pre- and manifest HTN. Yet, identifying and confirming the effectiveness of exercise are challenging. Herein, we discuss conventional and novel biomarkers such as extracellular vesicles (EVs) which may track responses to HTN before and after exercise.

RECENT FINDINGS

Evolving data shows that improved aerobic fitness and vascular function as well as lowered oxidative stress, inflammation, and gluco-lipid toxicity are leading biomarkers considered to promote HTN, but they explain only about a half of the pathophysiology. Novel biomarkers such as EVs or microRNA are providing additional input to understand the complex mechanisms involved in exercise therapy for HTN patients. Conventional and novel biomarkers are needed to fully understand the integrative "cross-talk" between tissues to regulate vasculature physiology for blood pressure control. These biomarker studies will lead to more specific disease markers and the development of even more personalized therapy in this field. However, more systematic approaches and randomized controlled trials in larger cohorts are needed to assess exercise effectiveness across the day and with different exercise types.

Association of pre-diagnostic physical exercise and peri-diagnostic body composition with mortality in non-metastatic colorectal cancer

PURPOSE

Sarcopenia and myosteatosis, quantified via computed tomography (CT), are associated with poor colorectal cancer outcomes. These body composition estimates can be influenced by physical exercise. We explored the correlation between pre-diagnostic physical exercise, body composition close to diagnosis, and the combined prognosis impact of these factors.

METHODS

We studied 519 stage I-III colorectal cancer (CRC) cases diagnosed 2000-2016 with pre-diagnostic self-reported recreational physical exercise data collected in the prospective, population-based Northern Sweden Health and Disease Study, and CT-estimated skeletal muscle index (SMI) or skeletal muscle density (SMD). Risk estimates were calculated by multivariable logistic regression and Cox proportional hazards models.

RESULTS

No association was seen between low pre-diagnostic physical exercise and sarcopenia/myosteatosis in the multivariable model adjusted for age, sex, educational level, tumor stage, and tumor location. In multivariable Cox regression models, the combination of low pre-diagnostic physical exercise and either sarcopenia or myosteatosis at the time of diagnosis was associated with cancer-specific mortality compared to the reference group of high physical exercise combined with no sarcopenia/myosteatosis (adjusted HR 1.94 95% CI 1.00-3.76 for sarcopenia and adjusted HR 2.39 95% CI 1.16-4.94 for myosteatosis).

CONCLUSIONS

The combined presence of low pre-diagnostic physical exercise and sarcopenia or myosteatosis was associated with increased CRC-specific mortality. Despite the positive effect on prognosis, physical exercise did not alter body composition estimates at diagnosis, which could indicate attenuation from other factors.

Can Exercise Enhance the Efficacy of Checkpoint Inhibition by Modulating Anti-Tumor Immunity?

Immune checkpoint inhibition (ICI) has revolutionized cancer therapy. However, response to ICI is often limited to selected subsets of patients or not durable. Tumors that are non-responsive to checkpoint inhibition are characterized by low anti-tumoral immune cell infiltration and a highly immunosuppressive tumor microenvironment. Exercise is known to promote immune cell circulation and improve immunosurveillance. Results of recent studies indicate that physical activity can induce mobilization and redistribution of immune cells towards the tumor microenvironment (TME) and therefore enhance anti-tumor immunity. This suggests a favorable impact of exercise on the efficacy of ICI. Our review delivers insight into possible molecular mechanisms of the crosstalk between muscle, tumor, and immune cells. It summarizes current data on exercise-induced effects on anti-tumor immunity and ICI in mice and men. We consider preclinical and clinical study design challenges and discuss the role of cancer type, exercise frequency, intensity, time, and type (FITT) and immune sensitivity as critical factors for exercise-induced impact on cancer immunosurveillance.

The Effect of Moderate-Intensity Physical Exercise on Some Serum Inflammation Markers and the Immune System in Rats Fed Intermittent Fasting with a High-Fat Diet

Background and Objectives: This study aimed to investigate the impact of moderate-intensity physical exercise on serum inflammation markers and the immune system in rats that were fed a high-fat diet (HFD) with intermittent fasting. Materials and Methods: A total of 48 Wistar albino male rats were included in the study and divided into eight groups, each consisting of six rats. Group 1 served as the control group (CG), receiving a standard diet. Group 2 followed the standard nutrition program with intermittent fasting (CG + IF). Group 3 underwent exercise with a standard diet (CG + E). Group 4 underwent both a standard diet with intermittent fasting and exercise (CG + IF + E). Group 5 was fed a high-fat diet (HFD). Group 6 received a high-fat diet with intermittent fasting (HFD + IF). Group 7 followed a high-fat diet with exercise (HFD + E). Group 8 underwent both a high-fat diet with intermittent fasting and exercise (HFD + IF + E). The study lasted for 8 weeks. Results: The results of the analysis show that lymphocyte cell levels in groups HFD + IF, HFD + IF, and HFD + IF + E were higher compared to groups CG-HFD (p < 0.05). Additionally, B lymphocyte and monocyte cell levels were higher in group HFD + IF + E compared to groups CG, CG + IF, and CG + IF + E, as well as CG, CG + IF, and CG + E, respectively. TNF-α levels were significantly higher in group HFD compared to the other groups. Furthermore, IL 10 levels were higher in group HFD + IF + E compared to the other groups. Conclusions: These findings indicate that moderate exercise and intermittent fasting, particularly in groups fed a high-fat diet, increased anti-inflammatory cytokine levels, and certain immune system cell counts, while decreasing pro-inflammatory cytokine levels.

Harnessing the immunomodulatory effects of exercise to enhance the efficacy of monoclonal antibody therapies against B-cell haematological cancers: a narrative review

Therapeutic monoclonal antibodies (mAbs) are standard care for many B-cell haematological cancers. The modes of action for these mAbs include: induction of cancer cell lysis by activating Fcγ-receptors on innate immune cells; opsonising target cells for antibody-dependent cellular cytotoxicity or phagocytosis, and/or triggering the classical complement pathway; the simultaneous binding of cancer cells with T-cells to create an immune synapse and activate perforin-mediated T-cell cytotoxicity against cancer cells; blockade of immune checkpoints to facilitate T-cell cytotoxicity against immunogenic cancer cell clones; and direct delivery of cytotoxic agents via internalisation of mAbs by target cells. While treatment regimens comprising mAb therapy can lead to durable anti-cancer responses, disease relapse is common due to failure of mAb therapy to eradicate minimal residual disease. Factors that limit mAb efficacy include: suboptimal effector cell frequencies, overt immune exhaustion and/or immune anergy, and survival of diffusely spread tumour cells in different stromal niches. In this review, we discuss how immunomodulatory changes arising from exposure to structured bouts of acute exercise might improve mAb treatment efficacy by augmenting (i) antibody-dependent cellular cytotoxicity, (ii) antibody-dependent cellular phagocytosis, (iii) complement-dependent cytotoxicity, (iv) T-cell cytotoxicity, and (v) direct delivery of cytotoxic agents.

Calorie Restriction Impairs Anti-Tumor Immune Responses in an Immunogenic Preclinical Cancer Model

(1) Background: Although the important role of dietary energy intake in regulating both cancer progression and host immunity has been widely recognized, it remains unclear whether dietary calorie restriction (CR) has any impact on anti-tumor immune responses. (2) Methods: Using an immunogenic B16 melanoma cell expressing ovalbumin (B16-OVA), we examined the effect of the CR diet on B16-OVA tumor growth and host immune responses. To further test whether the CR diet affects the efficacy of cancer immunotherapy, we examined the effect of CR against anti-PD-1 monoclonal antibody (anti-PD-1 Ab) treatment. (3) Results: The CR diet significantly slowed down the tumor growth of B16-OVA without affecting both CD4+ and CD8+ T cell infiltration into the tumor. Although in vivo depletion of CD8+ T cells facilitated B16-OVA tumor growth in the control diet group, there was no significant change in the tumor growth in the CR diet group with or without CD8+ T cell-depletion. Anti-PD-1 Ab treatment lost its efficacy to suppress tumor growth along with the activation and metabolic shift of CD8+ T cells under CR condition. (4) Conclusions: Our present results suggest that a physical condition restricted in energy intake in cancer patients may impair CD8+ T cell immune surveillance and the efficacy of immunotherapy.

Exercise therapy to prevent and treat Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease in the elderly with dementia, memory loss, and severe cognitive impairment that imposes high medical costs on individuals. The causes of AD include increased deposition of amyloid beta (Aβ) and phosphorylated tau, age, mitochondrial defects, increased neuroinflammation, decreased synaptic connections, and decreased nerve growth factors (NGF). While in animals moderate-intensity exercise restores hippocampal and amygdala memory through increased levels of p-AKT, p-TrkB, and p-PKC and decreased levels of Aβ, tau phosphorylation, and amyloid precursor proteins (APP) in AD. Aerobic exercise (with an intensity of 50-75% of VO2 max) prevents hippocampal volume reduction, spatial memory reduction, and learning reduction through increasing synaptic flexibility. Exercise training induces the binding of brain-derived neurotrophic factor (BDNF) to TrkB and the binding of NGF to TrkA to induce cell survival and neuronal plasticity. After aerobic training and high-intensity interval training, the increase of VEGF, angiopoietin 1 and 2, NO, tPA, and HCAR1 in cerebral vessels causes increased blood flow and angiogenesis in the cerebellum, motor cortex, striatum, and hippocampus. In the hippocampus, exercise training decreases mitochondrial fragmentation, DRP1, and FIS1, improving OPA1, MFN1, MFN2, and mitochondrial morphology. In humans, acute exercise as an anti-inflammatory condition causes an acute increase in IL-6 and an increase in anti-inflammatory factors such as IL-1RA and IL-10. Moderate-intensity exercise also inhibits inflammatory markers such as IFN-γ, IL-1β, IL-6, CRP, TNF-α, sTNFR1, COX-2, and NF-κB. Aerobic exercise significantly increases plasma levels of BDNF, nerve growth factor, synaptic plasticity, motor activity, spatial memory, and exploratory behavior in AD subjects. Irisin is a myokine released from skeletal muscle during exercise and protects the hippocampus by suppressing Aβ accumulation and promoting hippocampal proliferation through STAT3 signaling. Therefore, combined exercise training such as aerobic training, strength training, balance and coordination training, and cognitive and social activities seems to provide important benefits for people with AD.

Physical activity in lactating women influences SARS-CoV-2-specific antibodies in human milk

Background

Moderate exercise results in a significant increase in serum and salivary immunoglobulins. Maternal physical activity might therefore also be a factor influencing antibody levels in human milk. This study aims to determine the influence of physical activity on SARS-CoV-2-specific Immunoglobulin A (IgA) in human milk and Immunoglobulin G (IgG) in serum.

Methods

In this prospective cross-sectional cohort study, all lactating women in the Netherlands were eligible to participate. SARS-CoV-2-specific IgA in human milk and IgG in serum were determined using an enzyme-linked immunosorbent assay (ELISA). Data on performed physical activity was collected using the Short Questionnaire to Assess Health enhancing physical activity (SQUASH), which includes intensity and duration of the performed activity.

Findings

In total, 356 out of 2312 lactating women tested positive for SARS-CoV-2-specific antibodies in serum. Of them, 323 filled in the questionnaire and were included in the analysis. An association between the activity score and SARS-CoV-2-specific antibodies in human milk (B = 1·035, 95·0% CI = 1·019 to 1·052, p = 0·042) and serum (B = 1·019, 95·0% CI = 1·009 to 1·029, p = 0·048) was demonstrated. No association was found between the duration of physical activity and SARS-CoV-2-specific antibodies in human milk or serum.

Interpretation

Our findings suggest that physical activity is beneficial for the levels of SARS-CoV-2-specific antibodies in human milk and serum, with the intensity of the physical activity being the most important contributor to this relationship. A higher level of antibodies in human milk might provide better immunological protection for infants against COVID-19.

Seasonal changes in physiological and psychological parameters of stress in collegiate swimmers

To investigate the seasonal changes in physiological and psychological parameters of stress in collegiate swimmers. Fifteen NCAA Division I swimmers (8 men) participated in a tethered anaerobic swim test to determine physiological responses in an ecologically-relevant, graded exercise test. Wisconsin Upper Respiratory Symptom Survey (WURSS-21), Activation-Deactivation Adjective Check List (AD-ACL), Daily Analysis of Life Demands of Athletes (DALDA), and Pittsburgh Sleep Quality Index were assessed at post-season in April (V1), the end of off-season in June (V2), and pre-season in October (V3). The percent change was determined from V2-V1 (off-season phase), V3-V2 (pre-season phase), V1-V3 (in-season phase). Spearman's rho correlation was used to examine associations between change in physiological and psychological outcomes. All data results showed a better swim performance occurred at V2. Men tended to have faster speed (p = 0.07) in fewer strokes (p = 0.10) and greater work per stroke (p = 0.10) at V2 than V1. Women were faster during V2 compared to V1 (p = 0.02) and V3 (p = 0.05). Women had fewer strokes (p = 0.02) and greater work per stroke (p = 0.01) at V2 compared to V3. Women had the lowest HR and lactate concentration at V3 compared to other visits (p < 0.05). During the in-season phase, swim speed decreased the greatest extent and stress sources and symptoms assessed by DALDA had greatest elevation (p < 0.05). An increased in stress sources and symptoms assessed by DALDA was associated with an increase in upper respiratory illness from WURSS-21 (rho = 0.44, p = 0.009), being less energetic (rho = - 0.35, p = 0.04) and greater tension state (rho = 0.49, p = 0.003; AD-ACL), and a decrease in swim speed (rho =- 0.38, p = 0.03). Swim performance peaked at off-season when psychological stress was at its lowest. The relationship between DALDA scores with psychological parameters and swim performance suggested physiological and psychological parameters of stress is an important aspect to avoid overtraining when approaching high swim performance.

Examining Physical Wellness as the Fundamental Element for Achieving Holistic Well-Being in Older Persons: Review of Literature and Practical Application in Daily Life

This review examines the impact of physical activity, nutrition, and sleep evaluations on the physical wellness (PW) and overall well-being of older individuals. A comprehensive search was conducted in databases like PubMed, Google Scholar, and EBSCO Information Services. The search spanned from January 2000 to December 2022, resulting in 19,400 articles, out of which 98 review articles met the inclusion criteria. Through the analysis of these articles, key characteristics of the literature were summarized, and opportunities to enhance the practical application of physical activity (PA), nutrition, and sleep evaluations in the daily lives of older persons were identified. Regular physical activity is crucial for older persons to maintain their physical, mental, and emotional well-being and prevent age-related health issues. Older persons have specific nutritional needs, including increased protein, vitamin D, calcium, and vitamin B12 intake. Poor sleep quality in older persons is associated with negative health outcomes such as cognitive decline, physical disability, and mortality. This review emphasizes the significance of considering physical wellness as a fundamental element for achieving holistic well-being in older persons and highlights the importance of physical activity, nutrition, and sleep evaluations in improving their overall health and well-being. By understanding and implementing these findings, we can enhance the quality of life and promote healthy aging in older persons.

Respiratory issues in patients with multiple sclerosis as a risk factor during SARS-CoV-2 infection: a potential role for exercise

Coronavirus disease-2019 (COVID-19) is associated with cytokine storm and is characterized by acute respiratory distress syndrome (ARDS) and pneumonia problems. The respiratory system is a place of inappropriate activation of the immune system in people with multiple sclerosis (MS), and this may cause damage to the lung and worsen both MS and infections.The concerns for patients with multiple sclerosis are because of an enhance risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The MS patients pose challenges in this pandemic situation, because of the regulatory defect of autoreactivity of the immune system and neurological and respiratory tract symptoms. In this review, we first indicate respiratory issues associated with both diseases. Then, the main mechanisms inducing lung damages and also impairing the respiratory muscles in individuals with both diseases is discussed. At the end, the leading role of physical exercise on mitigating respiratory issues inducing mechanisms is meticulously evaluated.

Chromosome-Level Genome Assembly Provides Insights into the Evolution of the Special Morphology and Behaviour of Lepturacanthus savala

Savalani hairtail Lepturacanthus savala is a widely distributed fish along the Indo-Western Pacific coast, and contributes substantially to trichiurid fishery resources worldwide. In this study, the first chromosome-level genome assembly of L. savala was obtained by PacBio SMRT-Seq, Illumina HiSeq, and Hi-C technologies. The final assembled L. savala genome was 790.02 Mb with contig N50 and scaffold N50 values of 19.01 Mb and 32.77 Mb, respectively. The assembled sequences were anchored to 24 chromosomes by using Hi-C data. Combined with RNA sequencing data, 23,625 protein-coding genes were predicted, of which 96.0% were successfully annotated. In total, 67 gene family expansions and 93 gene family contractions were detected in the L. savala genome. Additionally, 1825 positively selected genes were identified. Based on a comparative genomic analysis, we screened a number of candidate genes associated with the specific morphology, behaviour-related immune system, and DNA repair mechanisms in L. savala. Our results preliminarily revealed mechanisms underlying the special morphological and behavioural characteristics of L. savala from a genomic perspective. Furthermore, this study provides valuable reference data for subsequent molecular ecology studies of L. savala and whole-genome analyses of other trichiurid fishes.

Involvement of Matrix Metalloproteinases in COVID-19: Molecular Targets, Mechanisms, and Insights for Therapeutic Interventions

MMPs are enzymes involved in SARS-CoV-2 pathogenesis. Notably, the proteolytic activation of MMPs can occur through angiotensin II, immune cells, cytokines, and pro-oxidant agents. However, comprehensive information regarding the impact of MMPs in the different physiological systems with disease progression is not fully understood. In the current study, we review the recent biological advances in understanding the function of MMPs and examine time-course changes in MMPs during COVID-19. In addition, we explore the interplay between pre-existing comorbidities, disease severity, and MMPs. The reviewed studies showed increases in different MMP classes in the cerebrospinal fluid, lung, myocardium, peripheral blood cells, serum, and plasma in patients with COVID-19 compared to non-infected individuals. Individuals with arthritis, obesity, diabetes, hypertension, autoimmune diseases, and cancer had higher MMP levels when infected. Furthermore, this up-regulation may be associated with disease severity and the hospitalization period. Clarifying the molecular pathways and specific mechanisms that mediate MMP activity is important in developing optimized interventions to improve health and clinical outcomes during COVID-19. Furthermore, better knowledge of MMPs will likely provide possible pharmacological and non-pharmacological interventions. This relevant topic might add new concepts and implications for public health in the near future.

Impact of maximal exercise on immune cell mobilization and bioenergetics

Acute aerobic exercise increases the number and proportions of circulating peripheral blood mononuclear cells (PMBC) and can alter PBMC mitochondrial bioenergetics. In this study, we aimed to examine the impact of a maximal exercise bout on immune cell metabolism in collegiate swimmers. Eleven (7 M/4F) collegiate swimmers completed a maximal exercise test to measure anaerobic power and capacity. Pre- and postexercise PBMCs were isolated to measure the immune cell phenotypes and mitochondrial bioenergetics using flow cytometry and high-resolution respirometry. The maximal exercise bout increased circulating levels of PBMCs, particularly in central memory (KLRG1+/CD57-) and senescent (KLRG1+/CD57+) CD8+ T cells, whether measured as a % of PMBCs or as absolute concentrations (all p < 0.05). At the cellularlevel, the routine oxygen flow (IO₂ [pmol·s^-1 ·10⁶ PBMCs^-1 ]) increased following maximal exercise (p = 0.042); however, there were no effects of exercise on the IO₂ measured under the LEAK, oxidative phosphorylation (OXPHOS), or electron transfer (ET) capacities. There were exercise-induced increases in the tissue-level oxygen flow (IO_2-tissue [pmol·s^-1 ·mL blood^-1 ]) for all respiratory states (all p < 0.01), except for the LEAK state, after accounting for the mobilization of PBMCs. Future subtype-specific studies are needed to characterize further maximal exercise's true impact on immune cell bioenergetics.

Acute exercise induces distinct quantitative and phenotypical T cell profiles in men with prostate cancer

Background

Reduced testosterone levels can influence immune system function, particularly T cells. Exercise during cancer reduces treatment-related side effects and provide a stimulus to mobilize and redistribute immune cells. However, it is unclear how conventional and unconventional T cells (UTC) respond to acute exercise in prostate cancer survivors compared to healthy controls.

Methods

Age-matched prostate cancer survivors on androgen deprivation therapy (ADT) and those without ADT (PCa) along with non-cancer controls (CON) completed ∼45 min of intermittent cycling with 3 min at 60% of peak power interspersed by 1.5 min of rest. Fresh, unstimulated immune cell populations and intracellular perforin were assessed before (baseline), immediately following (0 h), 2 h, and 24 h post-exercise.

Results

At 0 h, conventional T cell counts increased by 45%-64% with no differences between groups. T cell frequency decreased by -3.5% for CD3+ and -4.5% for CD4+ cells relative to base at 0 h with CD8+ cells experiencing a delayed decrease of -4.5% at 2 h with no group differences. Compared to CON, the frequency of CD8+CD57+ cells was -18.1% lower in ADT. Despite a potential decrease in maturity, ADT increased CD8+perforin+ GMFI. CD3+Vα7.2+CD161+ counts, but not frequencies, increased by 69% post-exercise while CD3+CD56+ cell counts increased by 127% and were preferentially mobilized (+1.7%) immediately following the acute cycling bout. There were no UTC group differences. Cell counts and frequencies returned to baseline by 24 h.

Conclusion

Following acute exercise, prostate cancer survivors demonstrate normal T cell and UTC responses that were comparable to CON. Independent of exercise, ADT is associated with lower CD8+ cell maturity (CD57) and perforin frequency that suggests a less mature phenotype. However, higher perforin GMFI may attenuate these changes, with the functional implications of this yet to be determined.

Effects of Covid-19 on the autonomic nervous system in elite athletes assessed by heart rate variability

Introduction

Covid-19 is a viral airway and systemic infection which can negatively affect the function of the autonomic nervous system. Cardiovascular autonomic function is essential for peak athletic performance. The aim of this study was to assess the effects of a Covid-19 disease on the autonomic nervous system of German elite athletes using heart rate variability (HRV).

Methods

60 elite athletes (aged 22.88 ± 4.71 years) were recruited, 30 of whom had undergone a Covid-19 disease. Heart rate (HR), blood pressure (BP) and heart rate variability (HRV) were measured during rest and during an orthostatic challenge.

Results

At rest and after orthostatic stress blood pressure and the root mean square of successive differences (RMSDD) were significantly lower in Covid-19 athletes (COV) than in control athletes (CON) (p = 0.002 and p = 0.004, respectively); heart rate was significantly higher (p = 0.001). COV showed a significantly greater reduction in blood pressure and elevation of heart rate than CON, but the change in RMSSD did not differ significantly during the orthostatic challenge.

Conclusion

These results show a change in cardiac parasympathetic activity and cardiovascular autonomic function in German elite athletes after Covid-19. These findings further the understanding of effects of the Covid-19 disease on the cardiovascular physiology in athletes. Heart rate variability may be a helpful tool in the return-to-play assessment of elite athletes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11332-023-01067-7.

The effects of exercise training for eight weeks on immune cell characteristics among breast cancer survivors

Methods

This study examined the effects of exercise training for 8 weeks on blood immune cell characteristics among 20 breast cancer survivors (age 56 ± 6 years, Body Mass Index 25.4 ± 3.0 kg m²) within two years of treatment. Participants were randomly allocated to a partly-supervised or a remotely-supported exercise group (n = 10 each). The partly supervised group undertook 2 supervised (laboratory-based treadmill walking and cycling) and 1 unsupervised session per week (outdoor walking) progressing from 35 to 50 min and 55% to 70% V˙O₂max. The remotely-supported group received weekly exercise/outdoor walking targets (progressing from 105 to 150 min per week 55% to 70% V˙O₂max) via weekly telephone calls discussing data from a fitness tracker. Immune cell counts were assessed using flow cytometry: CD4+ and CD8+ T cells (Naïve, NA; Central memory, CM; and Effector cells, EM and EMRA; using CD27/CD45RA), Stem cell-like memory T cells (TSCMs; using CD95/CD127), B cells (plasmablasts, memory, immature and naïve cells using CD19/CD27/CD38/CD10) and Natural Killer cells (effector and regulatory cells, using CD56/CD16). T cell function was assessed by unstimulated HLA-DR expression or interferon gamma (IFN-γ) production with Enzyme-linked ImmunoSpot assays following stimulation with virus or tumour-associated antigens.

Results

Total leukocyte counts, lymphocytes, monocytes and neutrophils did not change with training (p > 0.425). Most CD4+ and CD8+ T cell subtypes, including TSCMs, and B cell and NK cell subtypes did not change (p > 0.127). However, across groups combined, the CD4+ EMRA T cell count was lower after training (cells/µl: 18 ± 33 vs. 12 ± 22, p = 0.028) and these cells were less activated on a per cell basis (HLA-DR median fluorescence intensity: 463 ± 138 vs. 420 ± 77, p = 0.018). Furthermore, the partly-supervised group showed a significant decrease in the CD4+/CD8+ ratio (3.90 ± 2.98 vs. 2.54 ± 1.29, p = 0.006) and a significant increase of regulatory NK cells (cells/µl: 16 ± 8 vs. 21 ± 10, p = 0.011). T cell IFN-γ production did not change with exercise training (p > 0.515).

Discussion

In summary, most immune cell characteristics are relatively stable with 8 weeks of exercise training among breast cancer survivors. The lower counts and activation of CD4+ EMRA T cells, might reflect an anti-immunosenescence effect of exercise.