Karsten Krüger

University of Giessen | JLU · Department of Exercise Physiology and Sports Therapy

Long term cigarette smoking induces inflammatory processes in the pulmonary system which are suggested to "spill over" into systemic inflammation. Regular exercise has been shown to have anti-inflammatory properties. The aim of the study was to investigate the effects of therapeutic exercise on inflammation and muscle wasting in smoke-exposed mice....

In this consensus statement on immunonutrition and exercise, a panel of knowledgeable contributors from across the globe provides a consensus of updated science, including the background, the aspects for which a consensus actually exists, the controversies and, when possible, suggested directions for future research.

Objective Interterritorial regions of articular cartilage matrix are rich in decorin, a small leucine-rich proteoglycan and important structural protein, also involved in many signalling events. Decorin sequesters transforming growth factor β (TGFβ), thereby regulating its activity. Here, we analysed whether increased bioavailability of TGFβ in dec...

Introduction: High intensity interval exercise (HIT) has gained much interest in both performance and recreational sports. This study aims to compare the effect of HIT versus continuous exercise (CONT) with regard to changes of circulating T cells and progenitor cells. Methods: Subjects (n=23) completed a HIT test and an isocaloric CONT test. Bl...

Acute endurance exercise has been shown to modulate COX-2-expression, which is suggested to affect neuronal plasticity and learning. Here, we investigated the effect of regular strength and endurance training on cerebral COX-2-expression, inflammatory markers in the brain and circulating cytokines. Male C57BL/6N mice were assigned to either a seden...

The role of power performance in elite athletes has been enriched by identifying associations between specific single nucleotide polymorphisms (SNPs) and power performance. To deepen our understanding of this association, the objective of this study was to explore the relationship between the genotype and the phenotype in elite athletes. A total of...

Elite athletes are high-performance outliers within their specific sports. Even though science seeks to understand the nature of expertise and elite performance, much knowledge remains compartmentalized within subdisciplines. Despite this multidimensionality being acknowledged, an interdisciplinary approach to understanding elite athletes is still...

Functional cognition is relevant for athletic success and interdependent with physical exercise, yet despite repeatedly demonstrated inflammatory responses to physical training, there are no studies addressing the relationship between cognition and inflammation in athletes. The aim of this study was to investigate the relationship between cognitive...

› For athletes, iron plays an important role in improving oxygen supply, energy production, muscle function, and cognitive performance. However, iron deficiency is a common problem in athletes, especially endurance athletes, due to factors such as increased iron loss due to exercise-induced sweating, hematuria, and gastrointestinal bleeding. Exerci...

Objectives The global increase in physical inactivity is progressively evolving into a significant health challenge. Alongside the promotion of more active leisure pursuits, elevating physical activity in the workplace has coming into focus. Financial incentives are not only a popular, but also promising tool in this regard. According to behavioral...

Peak performances in different life domains are often achieved by healthy young- or middle-aged adults and are partly based on their executive functions. The extensive literature on older or non-healthy populations suggests an adequate availability of vitamin D as essential for good executive functioning. However, for healthy young- or middle-aged...

This study aimed to compare the acute inflammatory response following high-intensity eccentric exercise between resistance-trained young and master athletes with similar performance levels. Resistance-trained young (n=8; 22±2 years) and master (n=8; 52±4 years) male athletes of a similar performance level performed a standardized high-intensity ecc...

Background: Musculoskeletal pain is a non-negligible multifaceted condition affecting more than 30% of the global population. Superficial heat therapy (HT), through increasing tissue temperatures, plays a role in increasing local metabolism and function and relieving pain. Knee (KP) and sports pain represent two relevant fields of superficial HT ap...

Introduction The menstrual cycle may affect well-being and physical performance of elite female athletes by interfering with the function of multiple physiological systems. The aim of this study was to characterize the symptoms of the menstrual cycle and their frequency in elite female volleyball players. Methods Twenty professional female volleyb...

Problem: Cardiorespiratory fitness (CRF) and mitochondrial function are important factors in health and disease. Even in immune cells, an effective metabolism is crucial for most major cellular functions, such as T-cell proliferation. Little is known about the relationship between CRF and mitochondrial metabolism of immune cells. Methods: In this...

Introduction The study aimed to investigate whether an exercise-induced pro-inflammatory response alters the perception as well as visual exploration of emotional body language in social interactions. Methods In a within-subject design, 19 male, healthy adults aged between 19 and 33 years performed a downhill run for 45 min at 70% of their VO2max...

Drawing on theories from the sociology of work and organizations, such as Leiter and Maslach's concept of burnout and Siegrist's model of effort–reward imbalance, this paper argues that burnout symptoms in elite sport are related to a mismatch of investment and gratification. Building on data from a sample of German elite athletes ( N = 312), findi...

Introduction The study aimed to investigate to what extent acute endurance exercise, especially eccentric exercise and cardiorespiratory fitness affect the metabolic profile of CD4 ⁺ cells. Methods 15 male, healthy adults aged between 20 and 33 years with a maximal oxygen uptake (VO 2max ) between 44 and 63 ml/kg/min performed a downhill run (DR)...

A better understanding of the cellular and molecular mechanisms that are involved in skeletal muscle adaptation to exercise is fundamentally important to take full advantage of the enormous benefits that exercise training offers in disease prevention and therapy. The aim of this study was to elucidate the transcriptional signatures that distinguish...

Background: Musculoskeletal pain is a non-negligible multifaceted condition affecting more than 30% of the global population. Superficial heat therapy (HT) through increasing tissues temperatures plays a role in increasing local metabolism and function and relieving pain. Knee pain and sports represent two relevant fields of superficial HT applicat...

By calculating regression trees, we analyzed the potential of each marker to predict its reregulation as well as objective and subjective measures of performance and recovery. Since only the best-performing models are described in the manuscript, we attached a supplement file (S1), which includes the complete result tables with all calculated model...

Purpose Physical exercise is crucial for healthy aging and plays a decisive role in the prevention of atherosclerotic cardiovascular disease (ASCVD). A higher level of cardiorespiratory fitness (CRF) in the elderly is associated with lower cardiovascular and all-cause mortality. This study investigated the association of CRF level with vascular fun...

The high interindividual variability of exercise response complicates the efficient use of blood-based biomarkers in sports. To address this problem, a useful algorithm to characterize the individual regulation and predictive value of different candidate markers will be developed. Forty-nine participants completed two identical exercise trials. Blo...

Simple Summary: The gut microbiota is fundamental for human health. This complex health construct is a pivotal part of performance development in athletes. The gut microbiota plays its role in the physiology of the athlete by influencing immune function, gut barrier integrity, macro-and micronutrient absorption, muscular efficiency, and the gut-bra...

Background Atherosclerosis forms the pathological basis for the development of cardiovascular disease. Since pathological processes initially develop without clinically relevant symptoms, the identification of early markers in the subclinical stage plays an important role for initiating early interventions. There is evidence that regulatory T cells...

Aim This study aimed to evaluate if physical activity is associated with systemic and cellular immunometabolic responses, in young adults after mild-to-moderate COVID-19 infection. Methods Mild- to- moderate post-COVID-19 patients (70.50 ± 43.10 days of diagnosis; age: 29.4 (21.9– 34.9) years; BMI: 25.5 ± 4.3 kg m² n = 20) and healthy age-matched...

Background Aging is accompanied by an impaired immune system and chronic low-grade inflammation, while the supply-status of anti-inflammatory micronutrients such as long-chain omega-3 fatty acids, vitamin D, folate and cobalamin is often critical in older people. Methods The aim of this randomised, double-blinded, 12-week intervention study with 1...

Guidelines for medical clearing after SARS-CoV-2 infection in elite athletes do not include T-cell immunity aspects despite its relevance in the course of COVID-19 disease. Therefore, we aimed to analyze T-cell-related cytokines before and after in-vitro activation of CD4⁺ T-cells. We sampled professional indoor sports athletes at medical clearing...

At present, various blood-based biomarkers have found their applications in the field of sports medicine. This current opinion addresses biomarkers that warrant consideration in future research for monitoring the athlete training load. In this regard, we identified a variety of emerging load-sensitive biomarkers, e.g., cytokines (such as IL-6), cha...

The present study aimed to compare the effects of vitamin D2 and vitamin D3 supplementation on concentrations of total and free 25(OH)D in plasma and the expression of genes involved in the innate immune system in peripheral blood mononuclear cells (PBMC) in weaned pigs. Five groups of pigs (with an initial body weight of around 9 kg) received basa...

Objectives The high inter-individual variability of exercise response complicates the efficient use of blood-based biomarkers in sports. To address the problem, a useful algorithm to characterize the individual regulation and predictive value of different candidate markers will be developed. Methods Forty-nine participants completed two identical e...

Blood-based biomarkers can provide an objective individualized measure of training load, recovery, and health status in order to reduce injury risk and maximize performance. Despite enormous potentials, especially owing to currently evolving technology, such as point-of-care testing, and advantages, in terms of objectivity and non-interference with...

Background Age-related accumulation of highly differentiated CD8⁺ effector memory re-expressing CD45RA (EMRA) T-cells and disruption of the kynurenine (KYN) pathway are associated with chronic inflammation and the development of insulin resistance. In this study the aim was to investigate the effects of 12-week combined strength and endurance exerc...

Regelmäßige körperliche Belastungen führen zu einer Auslenkung der Homöostase, was zu strukturellen und funktionellen Adaptationsprozessen in Geweben und Organen führt. Die Spezifika dieser Anpassungserscheinungen hängen von der Art der Störung der Homöostase ab, welche je nach Belastungsmodalität und -normativa eine differenzierte Adaptationsantwo...

Featured Application: The quantum dots-based assay described here uses fluorescence masking to detect protein-ligand and protein-protein interactions on a glass slide in a multifunctional way. This is used here for the stress protein HSP90α in purified form and in cell lysate. It can be further used for other different proteins. Abstract: HSP90α is...

Life expectancy has increased exponentially in the last century accompanied by disability, poor quality of life, and all-cause mortality in older age due to the high prevalence of obesity and physical inactivity in older people. Biologically, the aging process reduces the cell’s metabolic and functional efficiency, and disrupts the cell’s anabolic...

Obesity is a chronic disease associated with a wide range of ailments and a major cause of mortality in many societies as a serious health condition, many studies have emerged in the last decades to discuss the possible ways to prevent and treat this health threat. Since medicinal plants have always been used throughout history in all regions, rece...

Background Recovery from coronavirus disease 2019 (COVID-19) can be impaired by the persistence of symptoms or new-onset health complications, commonly referred to as Long COVID. In a subset of patients, Long COVID is associated with immune system perturbations of unknown etiology, which could be related to compromised immunoregulatory mechanisms....

Purpose The present study aims to investigate the acute response of potential exercise-sensitive biomarkers in capillary plasma to an acute incremental running test. In a second step, their concentration was compared to the changes in the venous serum. Methods Thirty-seven active young female and male adults completed a VO2max ramp test on a tread...

Background: Recovery from coronavirus disease 2019 (COVID-19) can be impaired by the persistence of symptoms or new-onset health complications, commonly referred to as Long COVID. In a subset of patients, Long COVID is associated with immune system perturbations of unknown etiology, which could be related to compromised immunoregulatory mechanisms....

The pandemic coronavirus disease 2019 (COVID-19) can cause multi-systemic symptoms that can persist beyond the acute symptomatic phase. The post-acute sequelae of COVID-19 (PASC), also referred to as long COVID, describe the persistence of symptoms and/or long-term complications beyond 4 weeks from the onset of the acute symptoms and are estimated...

The aim of this study was to investigate the metabolic and inflammatory fluctuations in two seasonal phases of badminton training, and the ability of youth badminton athletes to respond to an inflammatory challenge given by acute exercise on these markers. Thirteen youth badminton athletes who participated in national and international competitions...

This perspective review highlights the impact of physical exercise on immunometabolic responses in the past 5 years. Understanding immunometabolism as a part of immunological research is essential. Furthermore, the roles of both acute and chronic effects of physical exercise on health, aging, and chronic diseases in immunometabolic changes should b...

The current study analyzes the suitability and reliability of selected neurophysiological and vegetative nervous system markers as biomarkers for exercise and recovery in endurance sport. Sixty-two healthy men and women, endurance trained and moderately trained, performed two identical acute endurance tests (running trial 1 and running trial 2) fol...

Numerous studies demonstrated the strong link between dyslipidemia and the cardiovascular risk. Physical activity and exercise represent effective prevention and therapy strategies for dyslipidemia and at the same time counteract numerous comorbidities that often accompany the disease. The physiological mechanisms are manifold, and primary mechanis...

Introduction: Musculoskeletal pain (MP) is prevalent in our society, having a strong negative impact on physical and psychosocial quality of life. Heat therapy (HT) has been frequently described as a treatment strategy for musculoskeletal pain, but scientific evidence is still poor. The aim of the present Delphi method study is to gather a consens...

Feeding pattern is related to health status or chronic diseases, and this depends on the individual’s eating habits. Feeding organized with the right time to start and end during the day, promotes an internal biological rhythm, favoring molecular synchronization of the clock genes, which impose an effect on metabolism and immune cells, creating a p...

Background: The term immunometabolism describes cellular and molecular metabolic processes that control the immune system and the associated immune responses. Acute exercise and regular physical activity have a substantial influence on the metabolism and the immune system, so that both processes are closely associated and influence each other bidi...

Sportärztezeitung 01/22: Die Skelettmuskulatur stellt das größte Gewebe im menschlichen Körper dar und spielt eine wichtige Rolle beim Energie- und Eiweißstoffwechsel sowie bei der Krafterzeugung zur Fortbewegung und Stabilität. Gewebeverletzungen können die Funktionen des Muskels auf verschiedenen Ebenen stören und in völlig unterschiedlichen Dime...

Muskel-Skelett-Erkrankungen gehören zu den häufigsten berufsbedingten Erkrankungen in der Metallindustrie. Die Berufsgruppe der Schweißer fällt dort durch hohe Prävalenzen auf. Daher sind Maßnahmen zur Prävention und Gesundheitsförderung dieser Zielgruppe von großem Interesse. Die vorliegende Studienreihe hatte zum Ziel, gesundheitliche Probleme vo...

Minerals fulfil a wide variety of functions in the optimal functioning of the immune system. This review reports on the minerals that are essential for the immune system's function and inflammation regulation. We also discuss nutritional aspects of optimized mineral supply. The supply of minerals is important for the optimal function of the innate...

The mechanisms underlying the immunometabolic disturbances during skeletal muscle atrophy caused by a plethora of circumstances ranging from hospitalization to spaceflight missions, remain unknown. Here, we outline the possible pathways that might be dysregulated in such conditions and assess the potential of physical exercise to mitigate and promo...

Background. Cancer is the second and most common cause of death in developed countries, and epidemiological evidence suggests a similar trend in developing countries. Cancer is currently the cause of twelve percent of all deaths worldwide. The ERK pathway contains important modulators suitable for growth and proliferation, especially tumors. This p...

Abstract: Background: This proposal aims to explain some of the gaps in scientific knowledge on the natural history of coronavirus disease (COVID-19), with a specific focus on immune, inflammatory, and metabolic markers, in parallel with temporal assessment of clinical and mental health in patients with COVID-19. The study will explore the temporal...

Monocyte and lymphocyte subpopulations exhibit functions that vary between the anti- and pro-inflammatory spectrum, such as classic CD16- and non-classical CD16+ monocytes, as well as T helper 2 lymphocytes (Th2), the Th1/Th17 lymphocytes ratio, and T regulatory lymphocytes (Treg). Metabolic disease-associated inflammation is accompanied by an imba...

Background and Aims: We evaluated adipose tissue-derived hormones, body composition, serum metabolic profile, levels of brain-derived neurotrophic factor (BDNF), and the association of these parameters with the clinical outcome in patients with COVID-19. We sought to examine whether obesity, sex, and age influence the adipose tissue endocrine respo...

Ca²⁺ is an important intracellular second messenger known to regulate several cellular functions. This research aimed to investigate the mechanisms of exercise-induced immunosuppression by measuring intracellular calcium levels, Ca²⁺-regulating gene expression, and agonist-evoked proliferation of murine splenic T lymphocytes. Mice were randomly ass...

The aim of this study was to investigate differences in skeletal muscle gene expression of highly trained endurance and strength athletes in comparison to untrained individuals at rest and in response to either an acute bout of endurance or strength exercise. Endurance (ET, n = 8, ⩒O2max 67 ± 9 mL/kg/min) and strength athletes (ST, n = 8, 5.8 ± 3.0...

Objectives The aim was to investigate the effect of physical activity on periodontal health and HbA1c levels in patients with type 2 diabetes mellitus (T2DM) over a period of 6 months. Materials and methods Thirty-seven patients with non-insulin-dependent T2DM were included in the study. The intervention group ( n =20) performed physical activity...

Sirtuins are nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases that regulate numerous pathways such as mitochondrial energy metabolism in the human body. Lower levels of these enzymes were linked to diseases such as diabetes mellitus and were also described as a result of aging. Sirtuins were previously shown to be under the control o...