Current evidence indicates that acute aerobic exercise might increase domain-specific cognitive performance. However, only a small number of studies deduced the impact on lower and higher cognitive functions systematically or analyzed dose–response relationships and the underlying mechanisms. This study aimed to expose the dose–response relationships by investigating the influence of exercise duration on subjective and objective arousal, cognitive attention and visual recognition memory tasks. Nineteen participants (eight female; 25.69 ± 3.11 years) were included in a randomized, three-armed intervention study in a cross-over design. The participants completed three different interventions consisting of either 15, 30 or 45 min of cycling at 60–70% VO₂max. Arousal and cognitive measurements were taken before and immediately after (<2 min) exercise. All three interventions led to significant but comparable effects on self-perceived arousal, heart rate (HR) and rating of perceived exertion (RPE) (p < 0.05). Analysis of variance (ANOVA) indicated significant effects of exercise duration on visual recognition memory accuracy. Reaction times for higher and lower cognitive tasks did not change after exercise. Fifteen minutes of aerobic exercise was feasible to induce beneficial changes in self-perceived arousal. Processing speed of visual recognition memory and attention remained unaltered. Exercise exceeding fifteen minutes seemed to negatively impact visual recognition memory accuracy.

The purpose of this study was to investigate blood-based biomarkers and their regulation with regard to different recovery-stress states. A total of 35 male elite athletes (13 badminton, 22 soccer players) were recruited, and two venous blood samples were taken: one in a ‘recovered’ state (REC) after a minimum of one-day rest from exercise and another one in a ‘non-recovered’ state (NOR) after a habitual loading microcycle. Overall, 23 blood-based biomarkers of different physiologic domains, which address inflammation, muscle damage, and tissue repair, were analyzed by Luminex assays. Across all athletes, only creatine kinase (CK), interleukin (IL-) 6, and IL-17A showed higher concentrations at NOR compared to REC time points. In badminton players, higher levels of CK and IL-17A at NOR were found. In contrast, a higher value for S100 calcium-binding protein A8 (S100A8) at REC was found in badminton players. Similar differences were found for BDNF in soccer players. Soccer players also showed increased levels of CK, and IL-6 at NOR compared to REC state. Several molecular markers were shown to be responsive to differing recovery-stress states, but their suitability as biomarkers in training must be further validated.

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. Blood samples were collected before, immediately after, 3 hours after, and 24 hours after completion of exercise. Plasma concentrations of interleukin (IL-) 1RA, IL-6, IL-8, IL-10, IL-15, creatine kinase (CK), cortisol, c-reactive protein (CRP), lactate dehydrogenase (LDH), and thiobarbituric acid reactive substances (TBARS) were measured. Individualized regulation was analyzed using k-means clustering and a Group Assignment Quality (GAQ) score. Regression trees with a bootstrapped-aggregated approach were used to assess the predictive qualities of the markers. For most of the markers studied, a distinction can be made between individuals who show a stronger or weaker response to a particular endurance training program. The regulation of IL-6, IL-8, IL-10, and CK exhibited a high degree of stability within the individuals. Regarding the predictive power of the markers, for all dependent variables, the most accurate predictions were obtained for cortisol and IL-8 based on the baseline value. For CK, a good prediction of recovery of maximal strength and subjective feeling of exhaustion can be made. For IL-1RA and TBARS, especially their reregulation can be predicted if the baseline level is known. Focusing individual variations in biomarker responses, our results suggest the combined use of IL-6, IL-8, IL-10, and CK for the personalized management of stress and recovery cycles following endurance exercise.

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 278 German national squad athletes (156 males, 122 females) underwent genotyping, and their performance in a countermovement jump test (CMJ) and 10-m sprint was assessed. Genotype distribution was analyzed using Chi-square tests. Spearman correlation was employed to examine associations between selected SNPs (e.g., ACTN3, AGT, HSD17B14, IP6K3, MTRR, UCP2, and VDR) and CMJ and sprint performances. Gender-specific polygenic "Total Genotype Scores" (TGSsig) were calculated. Predictive power of TGSsig on power performance was evaluated using linear regression. TGSsig explained 10% of variance in CMJ and sprint performance in both genders. Among males, correlations were identified between AGT and VDR with the CMJ as well as between IP6K3 and sprint performance (p < 0.05). In females, ACTN3, AGT, and UCP2 exhibited associations with the CMJ, while HSD17B14, MTRR, and UCP2 were correlated with sprint performance (p < 0.05). Significant differences in genotype distribution between genders were observed for DMD and MPRIP. Our findings strengthen the idea of power being partly heritable, however, the genotype only partially, by 10%, determines power performance. The role of the athletes' genotype for individual performance development should be investigated in future longitudinal studies.

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) followed by a washout period of four weeks. Exercise protocol consisted of an acute running trial lasting 60 minutes. An intensity corresponding to 95% of the heart rate at individual anaerobic threshold for 40 minutes was followed by 20 minutes at 110%. At pre-exercise, post-exercise, three hours post-exercise and 24 hours post-exercise, experimental diagnostics on Brain-derived neurotrophic factor (BDNF), heart rate variability (HRV), Stroop Color and Word Test (SCWT), and Short-Form McGill Pain Questionnaire (SF-MPQ) were performed. Significant changes over time were found for all parameters (p < .05). Furthermore, there was an approached statistical significance in the interaction between gender and training status in BDNF regulation (F(3) = 2.43; p = 0.06), while gender differences were found only for LF/HF-ratio (3hPoEx, F(3) = 3.40; p = 0.002). Regarding the reliability, poor ICC-values (< 0.5) were found for BDNF, Stroop sensitivity and pNN50, while all other parameters showed moderate ICC-values (0.5-0.75). Plasma-BDNF, SCWT performance, pain perception and all HRV parameters are suitable exercise-sensitive markers after an acute endurance exercise. Moreover, pain perception, SCWT reaction time and all HRV parameters show a moderate reliability, others rather poor. In summary, a selected neurophysiological and vegetative marker panel can be used to determine exercise load and recovery in endurance sports, but its repeatability is limited due to its vaguely reliability.

Purpose: This study investigated elite German athletes to (1) assess their serum 25(OH)D levels and the prevalence of insufficiency, (2) identify key factors influencing serum 25(OH)D levels, and (3) analyze the association between serum 25(OH)D levels and handgrip strength. Methods: In this cross-sectional study, a total of 474 athletes (231 female), aged 13–39 years (mean 19.3 years), from ten Olympic disciplines were included. Serum 25(OH)D levels were analyzed via liquid chromatography–mass spectrometry, and 17 single nucleotide polymorphisms (SNPs) related to vitamin D metabolism were determined using leukocyte DNA. Grip strength was measured unimanually using a hand-held dynamometer. Multiple linear regressions were used to analyze the influence of SNPs, age, sex, season (summer vs. winter), and discipline (indoor vs. outdoor) on 25(OH)D status. Linear regression analyzed the relationship between handgrip strength and serum 25(OH)D levels. Results: In total, 55.5% (n = 263) of athletes demonstrated insufficient serum 25(OH)D levels (< 30 ng/mL, < 75 nmol/L), with 16% (n = 76) showing levels below 20 ng/mL (50 nmol/L). After correction for multiple testing, significant influences on 25(OH)D levels were observed for the C allele of VDBP rs7041 (AC Genotype: $$\widehat{\upbeta }$$ β ^ = 7.46, p < .001; CC Genotype: $$\widehat{\upbeta }$$ β ^ = 6.23, p = .001). Age (all p < .01) and discipline (indoor vs. outdoor; all p < .05) also influenced serum 25(OH)D levels. Furthermore, serum 25(OH)D was positively associated with handgrip strength ( $$\widehat{\upbeta }$$ β ^ = 0.01, p < .001). Conclusion: A high prevalence of insufficient 25(OH)D levels (< 30 ng/mL, < 75 nmol/L) was observed. We identified certain genetic variants as well as age and discipline as predictors of serum 25(OH)D levels. This knowledge may guide individualized diagnostic, nutritional, and supplementation strategies.