Hematological and hemorheological parameters are known to be altered in COVID-19; however, the value of combined monitoring in order to deduce disease severity is only scarcely examined. A total of 44 acute SARS-CoV-2-infected patients (aCOV) and 44 age-matched healthy controls (Con) were included. Blood of aCOV was sampled at admission (T0), and at day 2 (T2), day 5 (T5), day 10 (T10), and day 30 (T30) while blood of Con was only sampled once. Inter- and intra-group differences were calculated for hematological and hemorheological parameters. Except for mean cellular volume and mean cellular hemoglobin, all blood cell parameters were significantly different between aCOV and Con. During the acute disease state (T0–T5), hematological and hemorheological parameters were highly altered in aCOV; in particular, anemic conditions and increased immune cell response/inflammation, oxidative/nitrosative stress, decreased deformability, as well as increased aggregation, were observed. During treatment and convalescence until T30, almost all abnormal values of aCOV improved towards Con values. During the acute state of the COVID-19 disease, the hematological, as well as the hemorheological system, show fast and potentially pathological changes that might contribute to the progression of the disease, but changes appear to be largely reversible after four weeks. Measuring RBC deformability and aggregation, as well as oxidative stress induction, may be helpful in monitoring critically ill COVID-19 patients.

Moderate endurance exercise leads to an improvement in cardiovascular performance, stress resilience, and blood function. However, the influence of chronic endurance exercise over several hours or days is still largely unclear. We examined the influence of a non-stop 160.9/230 km ultramarathon on body composition, stress/cardiac response, and nutrition parameters. Blood samples were drawn before (pre) and after the race (post) and analyzed for ghrelin, insulin, irisin, glucagon, cortisol, kynurenine, neopterin, and total antioxidant capacity. Additional measurements included heart function by echocardiography, nutrition questionnaires, and body impedance analyses. Of the 28 included ultra-runners (7f/21m), 16 participants dropped out during the race. The remaining 12 finishers (2f/10m) showed depletion of antioxidative capacities and increased inflammation/stress (neopterin/cortisol), while energy metabolism (insulin/glucagon/ghrelin) remained unchanged despite a high negative energy balance. Free fat mass, protein, and mineral content decreased and echocardiography revealed a lower stroke volume, left end diastolic volume, and ejection fraction post race. Optimizing nutrition (high-density protein-rich diet) during the race may attenuate the observed catabolic and inflammatory effects induced by ultramarathon running. As a rapidly growing discipline, new strategies for health prevention and extensive monitoring are needed to optimize the athletes’ performance.

Background: Ultramarathon running represents an extreme physiological and metabolic challenge. Despite its growing popularity among recreational and competitive runners, evidence-based guidance for nutrition, energy balance, and recovery remains limited. Understanding metabolic response and hormonal regulation during such events is crucial for improving athletes’ health and performance. Methods: This prospective observational study examined participants of the 2024 TorTour de Ruhr^® (100 km, 160.9 km, and 230 km). Pre- and post-race assessments included body composition, energy intake and expenditure, metabolic and hormonal biomarkers (leptin, ghrelin, insulin, glucagon, irisin, creatine kinase muscle type (CKM), lactate dehydrogenase (LDH)), and continuous glucose monitoring (CGM). Blood and saliva samples, bioimpedance analysis, and validated symptom questionnaires (General Assessment of Side Effects (GASE)) were used. Results: Of the 43 ultra runners (16 women, 27 men), 39 finished the race: 19 participants of the 100 km group, 8 of the 160.9 km group, and 16 of the 230 km group. Mean energy deficit was 6797 kcal (range: 417–18,364 kcal) with carbohydrate-dominant fueling (79%). Significant reductions in leptin and insulin and increases in ghrelin, glucagon, CKM, and LDH were observed, indicating disrupted energy homeostasis and muscle damage. The 230 km subgroup showed the greatest changes. Gastrointestinal and musculoskeletal symptoms increased post-race, aligning with biomarker patterns. Conclusions: Ultramarathon participation induces profound disturbances in metabolic and structural integrity, regardless of race distance. These findings underline the importance of developing individualized nutritional and recovery strategies and highlight the need for future research to investigate how energy deficit and macronutrient composition interact to influence metabolic strain and post-race recovery.

Background: High prevalence rates of β2-agonist use among athletes in competitive sports makes it tempting to speculate that illegitimate use of β2-agonists boosts performance. However, data regarding the potential performance-enhancing effects of inhaled β2-agonists and its underlying molecular basis are scarce. Methods: In total, 24 competitive endurance athletes (12f/12m) participated in a clinical double-blinded balanced four-way block cross-over trial to investigate single versus combined effects of β2-agonists salbutamol (SAL) and formoterol (FOR), to evaluate the potential performance enhancement of SAL (1200 µg, Cyclocaps, Pb Pharma GmbH), FOR (36 µg, Sandoz, HEXAL AG) and SAL + FOR (1200 µg + 36 µg) compared to placebo (PLA, Gelatine capsules containing lactose monohydrate, Pharmacy of the University Hospital Ulm). Measurements included skeletal muscle gene and protein expression, endocrine regulation, urinary/serum β2-agonist concentrations, cardiac markers, cardiopulmonary and lung function testing and the 10-min time trial (TT) performance on a bicycle ergometer as outcome variables. Blood and urine samples were collected pre-, post-, 3 h post- and 24 h post-TT. Results: Mean power output during TT was not different between study arms. Treatment effects regarding lung function (p < 0.001), echocardiographic (left ventricular end-systolic volume p = 0.037; endocardial global longitudinal strain p < 0.001) and metabolic variables (e.g. NR4A2 and ATF3 pathway) were observed without any influence on performance. In female athletes, total serum β2-agonist concentrations for SAL and FOR were higher. Microarray muscle gene analysis showed a treatment effect for target genes in energy metabolism with strongest effect by SAL + FOR (NR4A2; p = 0.001). Of endocrine variables, follicle-stimulating hormone (3 h Post–Post-TT), luteinizing hormone (3 h Post–Pre-TT) and insulin (Post–Pre-TT) concentrations showed a treatment effect (all p < 0.05). Conclusions: No endurance performance-enhancing effect for SAL, FOR or SAL + FOR within the permitted dosages compared to PLA was found despite an acute effect on lung and cardiac function as well as endocrine and metabolic variables in healthy participants. The impact of combined β2-agonists on performance and sex-specific thresholds on the molecular and cardiac level and their potential long-term performance enhancing or health effects have still to be determined. Trial registration: Registered at Eudra CT with the number: 2015-005598-19 (09.12.2015) and DRKS with number DRKS00010574 (16.11.2021, retrospectively registered).

Blood profiling data in athletic populations and their respective responses to SARS-CoV-2 infection are lacking. Thus, this exploratory pilot study aimed to analyze and compare clinical blood markers in previously infected trained athletes (ATH; 30 m/29 f) and a not previously infected healthy athletic control group (HC; 12 m/19 f). The ATH group undertook a sports medical examination which included extended blood analyses. Blood profiles with a total of 74 variables were assessed (blood counts, pro-/inflammatory and immunological markers, and micronutrients), and the ATH group was compared to the age-matched, vaccinated HC group with comparable athletic back grounds, though without previous SARS-CoV-2-infections. The ATH group showed lower IgG, Troponin-T levels, and they had a lower complement/acute-phase protein activation. Furthermore, Vitamin D levels were lower and electrolyte/micronutrient concentrations were higher in ATH. Soluble transferrin receptor as a marker of erythrocyte turnover was decreased whereas PTT as a coagulation marker was increased. Subgroup analyses according to sex revealed more differences between the women of the ATH and HC groups (for 25 different variables) than between the men (for 5 different variables), especially for immunological and metabolic variables. In particular, the immune system and electrolyte/micronutrient status should be observed frequently and sex-specifically in this athletic cohort.

Endurance training camps are well established in elite sports, but one-week camps for recreational endurance athletes have recently gained popularity despite limited scientific evidence. This study investigated the effects of a one-week endurance training camp on body composition, endurance performance, and markers of metabolic stress and mitochondrial adaptation in recreational athletes. Female and male endurance athletes (≥18 years) participated in a professionally guided one-week endurance training camp. Assessments included body composition, running diagnostics, sleep-quality/recovery-stress questionnaires, nutrition/energy balance diaries, blood profiling, and mitochondrial biogenesis markers. Measurements were conducted before (pre), during (camp), and after the camp (post). A total of 35 participants (18 male/17 female) were included. Body mass and body fat decreased from pre- to post-camp. Lactate concentrations at threshold levels changed, while velocities at fixed lactate concentrations and maximal oxygen uptake did not significantly improve. Post-camp, lactate dehydrogenase, klotho, and vitamin D increased, whereas interferon-γ, kynurenine, cortisol, creatinine, and ferritin decreased. Plasma mitochondrial and nuclear DNA abundance, as well as PGC1-α expression, increased, while vascular endothelial growth factor decreased. A one-week endurance training camp in a holiday-like setting induces measurable physiological, metabolic, and mitochondrial adaptations in recreational athletes and is associated with reduced systemic and psychological stress. However, the concurrent increase in muscle- and cell-stress markers indicates a substantial physiological load.