Neuromuscular and Torque Kinetic Changes After 10 Months of Explosive Sport Training in Prepubertal Gymnasts.

PURPOSE: To determine neuromuscular and torque kinetic changes after 10 months of explosive sport training in the elbow of prepubertal gymnasts compared with untrained age-matched controls. METHODS: In 15 young gymnasts (9.02 [0.41] y) and 15 age-matched untrained males (8.76 [0.51] y), the rate of torque development (RTD) using the Biodex System 4 and the coactivation index were evaluated using electromyography. Explosive strength variables were normalized to the peak torque. Measures were determined twice: before and after a 10-month period of gymnastic training. Covariation analysis was used to account for differences in baseline values between gymnasts and controls. RESULTS: After 10 months of training, gymnasts demonstrated a significantly (P < .05) greater increase in normalized peak RTD values in elbow flexion compared with controls (7.76% vs 0.65%). Covariation analysis also revealed a significantly (P < .05) greater reduction in the coactivation index of elbow extension in the gymnasts (-7.81% [5.44%] points) compared with controls (-1.23% [6.32%] points). CONCLUSIONS: Compared with physical development alone, 10 months of explosive-strength training of young gymnasts is sufficient to increase torque-normalized RTD in the elbow joint of prepubertal boys. The RTD changes the authors observed in antagonistic elbow functions vary among gymnasts due to the specific demands of gymnastic training.

Changes in the Muscle Activity of Gymnasts During a Handstand on Various Apparatus.

Kochanowicz, A, Niespodzinski, B, Mieszkowski, J, Marina, M, Kochanowicz, K, and Zasada, M. Changes in the muscle activity of gymnasts during a handstand on various apparatus. J Strength Cond Res 33(6): 1609-1618, 2019-Gymnasts perform handstands on various apparatus, both in stable and unstable conditions. Such performances require specific muscle activation, which should differ depending on the condition and expertise of the gymnast. Therefore, the aim of the study was to evaluate (a) the difference in electromyography (EMG) between handstands performed on 3 apparatus (floor, rings, and parallel bars); and (b) the difference between young and well-trained adult gymnasts. Ten adult (25 ± 3.94 years) and 15 young (13.9 ± 0.7 years) gymnasts participated in the study. We investigated EMG amplitude in 13 muscles normalized by arbitrary angle maximal isometric voluntary contraction (normalized root mean square [NRMS]). In comparison with the handstand on the floor (61 ± 28%), the wrist flexor muscles of gymnasts exhibited a decreased NRMS on the parallel bars (44 ± 25%; p = 0.017), and rings (46 ± 32%; p = 0.029), whereas no changes were observed in the triceps brachii. The rest of the investigated muscles showed a higher NRMS in rings. Differences between young and adult gymnasts were seen in the triceps brachii and anterior deltoid muscles, where more experienced gymnasts showed 19.1% (p = 0.014) and 17.6% (p = 0.048) lower NRMS, respectively. The different gymnastic apparatus led to specific muscle activation. This activation predominantly depended on hand support conditions, which alternated the primary wrist strategy of the handstand balance control, and in consequence, the activation of other muscles controlling balance. Training focused on the development of motor control and strength of the anterior deltoid, pectoralis major, latissimus dorsi, biceps brachii, and trapezius descendens muscles to improve handstand performance.

Whole-body vibration exercise in postmenopausal osteoporosis.

The report of the World Health Organization (WHO) of 2008 defines osteoporosis as a disease characterized by low bone mass and an increased risk of fracture. Postmenopausal osteoporosis is connected to the decrease in estrogens concentration as a result of malfunction of endocrine ovarian function. Low estrogens concentration causes increase in bone demineralization and results in osteoporosis. Physical activity, as a component of therapy of patients with osteoporosis, has been used for a long time now. One of the forms of safe physical activity is the vibration training. Training is to maintain a static position or execution of specific exercises involving the appropriate muscles on a vibrating platform, the mechanical vibrations are transmitted to the body of the patient. According to the piezoelectric theory, pressure induces bone formation in the electrical potential difference, which acts as a stimulant of the process of bone formation. Whole body vibration increases the level of growth hormone and testosterone in serum, preventing sarcopenia and osteoporosis. The aim of this study was to review the literature on vibration exercise in patients with postmenopausal osteoporosis based on the PubMed and Medline database. While searching the database, the following key words were used 'postmenopausal osteoporosis' and 'whole-body vibration exercise'.

One-year developmental changes in motor coordination and tennis skills in 10-12-year-old male and female tennis players.

BACKGROUND: To date, no longitudinal studies of quarterly changes have been conducted on the differences in the development of motor coordination between boys and girls in relation to changes in their tennis skills level. Therefore, the aim of the study was to assess the development of motor coordination of 10-12-year-old tennis players over the course of 1 year, in the light of changes in tennis skills preparation. METHODS: One-hundred eighty male and female tennis players aged 10, 11, or 12 years old participated in the study. Each age group comprised 30 boys and 30 girls. To investigate their motor coordination development, a battery of general tests (simple reaction, complex reaction, Spalding test, spider test, hexagon jumping, Starosta's test, hand-eye test, balance, plate tapping, jump rope) and specific tennis skills tests (wall game and 100-tennis ball tests) were performed 4 times quarterly over 1 year. Differences between sexes and the time points were assessed. The rate of development evaluation was based on beta coefficient of linear regression. RESULTS: Boys generally performed better in tennis skills tests than girls. The boys performed better also in one motor coordination test (Spalding test) among 10-year-olds, in two additional tests (spider and plate tapping tests) among 11-year-olds, and another three more tests (simple reaction, complex reaction and Starosta's tests) among 12-year-olds. Jump rope test among 10-year-olds and hexagon jump test among 12-year-olds were the only tests where girls performed better than boys. On the other hand, girls showed higher rate of development in balance and complex reaction tests than boys. CONCLUSIONS: We conclude that motor coordination and tennis skills development over 1 year is age-, sex-, and task-dependent, with the 10-12-year-old male tennis players performing better in tennis skills and overall motor coordination than females.

Acute inflammatory response following lower-and upper-body Wingate anaerobic test in elite gymnasts in relation to iron status.

Introduction: Artistic gymnastics is one of the most demanding sports disciplines, with the athletes demonstrating extremely high levels of explosive power and strength. Currently, knowledge of the effect of gymnastic training adaptation on exercise-induced inflammatory response is limited. The study aimed to evaluate inflammatory response following lower- and upper-body high-intensity exercise in relation to the iron status in gymnasts and non-athletes. Methods: Fourteen elite male artistic gymnasts (EAG, 20.6 ± 3.3 years old) and 14 physically active men (PAM, 19.9 ± 1.0 years old) participated in the study. Venous blood samples were taken before and 5 min and 60 min after two variants of Wingate anaerobic test (WAnT), upper-body and lower-body WAnT. Basal iron metabolism (serum iron and ferritin) and acute responses of selected inflammatory response markers [interleukin (IL) 6, IL-10, and tumour necrosis factor α] were analysed. Results: EAG performed significantly better during upper-body WAnT than PAM regarding relative mean and peak power. The increase in IL-6 levels after upper-body WAnT was higher in EAG than in PAM; the opposite was observed after lower-body WAnT. IL-10 levels were higher in EAG than in PAM, and tumour necrosis factor α levels were higher in PAM than those in EAG only after lower-body WAnT. The changes in IL-10 correlated with baseline serum iron and ferritin in PAM. Discussion: Overall, gymnastic training is associated with the attenuation of iron-dependent post-exercise anti-inflammatory cytokine secretion.

Ubiquinone (Coenzyme Q-10) Supplementation Influences Exercise-Induced Changes in Serum 25(OH)D3 and the Methyl-Arginine Metabolites: A Double-Blind Randomized Controlled Trial.

Researchers have studied the effects of exercise on serum methyl-arginine and vitamin D metabolites; however, the effects of exercise combined with antioxidants are not well documented. Since oxidative stress affects the metabolism of vitamin D and methyl-arginine, we hypothesised that the antioxidant coenzyme Q10 (CoQ10) might modulate exercise-induced changes. A group of twenty-eight healthy men participated in this study and were divided into two groups: an experimental group and a control group. The exercise test was performed until exhaustion, with gradually increasing intensity, before and after the 21-day CoQ10 supplementation. Blood samples were collected before, immediately after, and 3 and 24 h after exercise. CoQ10, vitamin D metabolites, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine, methylarginine, dimethylamine, arginine, citrulline, and ornithine were analysed in serum samples. CoQ10 supplementation caused a 2.76-fold increase in the concentration of serum CoQ10. Conversely, the 25(OH)D3 concentration increased after exercise only in the placebo group. ADMA increased after exercise before supplementation, but a decrease was observed in the CoQ10 supplementation group 24 h after exercise. In conclusion, our data indicate that CoQ10 supplementation modifies the effects of exercise on vitamin D and methyl-arginine metabolism, suggesting its beneficial effects. These findings contribute to the understanding of how antioxidants like CoQ10 can modulate biochemical responses to exercise, potentially offering new insights for enhancing athletic performance and recovery.

Effect of Single High-Dose Vitamin D3 Supplementation on Post-Ultra Mountain Running Heart Damage and Iron Metabolism Changes: A Double-Blind Randomized Controlled Trial.

Exercise-induced inflammation can influence iron metabolism. Conversely, the effects of vitamin D3, which possesses anti-inflammatory properties, on ultramarathon-induced heart damage and changes in iron metabolism have not been investigated. Thirty-five healthy long-distance semi-amateur runners were divided into two groups: one group received 150,000 IU of vitamin D3 24 h prior to a race (n = 16), while the other group received a placebo (n = 19). Serum iron, hepcidin (HPC), ferritin (FER), erythroferrone (ERFE), erythropoietin (EPO), neopterin (NPT), and cardiac troponin T (cTnT) levels were assessed. A considerable effect of ultramarathon running on all examined biochemical markers was observed, with a significant rise in serum levels of ERFE, EPO, HPC, NPT, and cTnT detected immediately post-race, irrespective of the group factor. Vitamin D3 supplementation showed a notable interaction with the UM, specifically in EPO and cTnT, with no other additional changes in the other analysed markers. In addition to the correlation between baseline FER and post-run ERFE, HPC was modified by vitamin D. The ultramarathon significantly influenced the EPO/ERFE/HPC axis; however, a single substantial dose of vitamin D3 had an effect only on EPO, which was associated with the lower heart damage marker cTnT after the run.

Microbiome features associated with performance measures in athletic and non-athletic individuals: A case-control study.

The influence of human gut microbiota on health and disease is now commonly appreciated. Therefore, it is not surprising that microbiome research has found interest in the sports community, hoping to improve health and optimize performance. Comparative studies found new species or pathways that were more enriched in elites than sedentary controls. In addition, sport-specific and performance-level-specific microbiome features have been identified. However, the results remain inconclusive and indicate the need for further assessment. In this case-control study, we tested two athletic populations (i.e. strength athletes, endurance athletes) and a non-athletic, but physically active, control group across two acute exercise bouts, separated by a 2-week period, that measured explosive and high intensity fitness level (repeated 30-s all-out Wingate test (WT)) and cardiorespiratory fitness level (Bruce Treadmill Test). While we did not identify any group differences in alpha and beta diversity or significant differential abundance of microbiome components at baseline, one-third of the species identified were unique to each group. Longitudinal sample (pre- and post-exercise) analysis revealed an abundance of Alistipes communis in the strength group during the WT and 88 species with notable between-group differences during the Bruce Test. SparCC recognized Bifidobacterium longum and Bifidobacterium adolescentis, short-chain fatty acid producers with probiotic properties, species strongly associated with VO2max. Ultimately, we identified several taxa with different baseline abundances and longitudinal changes when comparing individuals based on their VO2max, average power, and maximal power parameters. Our results confirmed that the health status of individuals are consistent with assumptions about microbiome health. Furthermore, our findings indicate that microbiome features are associated with better performance previously identified in elite athletes.

Vitamin D Supplementation Influences Ultramarathon-Induced Changes in Serum Amino Acid Levels, Tryptophan/Branched-Chain Amino Acid Ratio, and Arginine/Asymmetric Dimethylarginine Ratio.

Exercise affects serum levels of amino acids and their metabolites, with important metabolic consequences. Since vitamin D impacts skeletal muscle protein degradation, we hypothesised that it would also impact exercise-induced changes in serum amino acid levels and the serum levels of arginine metabolites, influencing the body's ability to synthesise NO. Accordingly, we analysed the effect of a single high-dose vitamin D supplementation on the serum levels of various amino acids in ultramarathon runners. Thirty-five male amateur runners were assigned to the supplemented group, administered 150,000 IU vitamin D in vegetable oil 24 h before the run (n = 16), or the control (placebo) group (n = 19). Blood was sampled 24 h before, immediately after, and 24 h after the run. Changes in the serum levels of some amino acids were distinct in the two groups. The asymmetric dimethyl arginine levels were significantly decreased immediately after the run and increased 24 h later and were not affected by the supplementation. The symmetric dimethyl arginine levels were increased after the run in both groups but were lower in the supplemented group than in the placebo group 24 h after the run. The dimethylamine levels increased significantly in the supplemented group as compared to the placebo group. In conclusion, vitamin D impacts exercise-induced changes in serum amino acids and methylated arginine metabolites.

Effect of Supplementation with Black Chokeberry (Aronia melanocarpa) Extract on Inflammatory Status and Selected Markers of Iron Metabolism in Young Football Players: A Randomized Double-Blind Trial.

The use of herbal medicinal products and supplements in amateur and professional sports has increased in the last decades. This is because most of these products and supplements contain bioactive compounds with a variety of biological properties that exert a physiological effect on the human body. The aim of this study was to analyze the effect of dietary supplementation with lyophilized black chokeberry extract on the levels of pro-inflammatory cytokines, hepcidin, and selected markers of iron metabolism in a group of young football players. This double-blind study included 22 male football players (mean = 19.96 ± 0.56), divided into two groups: supplemented and placebo. Before and after a 90-day period of training combined with supplementation (6 g of lyophilized black chokeberry extract), participants performed maximal multistage 20-m shuttle run tests at the beginning and at the end of the supplementation period, with blood sampled for analysis at different times before and after exercise. The levels of IL-6, IL-10, ferritin, myoglobin, hepcidin, 8-OHdG, albumin, and TAC were analyzed. The analysis of variance revealed a significant effect of 90-day supplementation with the lyophilized extract on changes in the IL-6 and IL-10 levels, and TAC induced by maximal aerobic effort. In conclusion, supplementation with lyophilized black chokeberry extract improves the performance and antioxidant status of serum in humans and induces protective changes in inflammatory markers.

Gross motor coordination and their relationship with body mass and physical activity level during growth in Children aged 8-11 years old: a longitudinal and allometric approach.

Background: Gross motor coordination (GMC) is fundamental to the harmonious development of physical skills during the growth of children. This research aimed to explore the developmental changes in GMC during childhood, having controlled for the differences in children's body size and shape using a longitudinal, allometric scaling methodology. Methods: A total of 104 children from North-East Italy of third-fourth- and fifth-grade students and each participant were tested for three consequently years. Subjects performed the short version of korperkoordinationstest fur kinder (KTK3) and the anthropometric characteristics were simultaneously collected. The physical activity questionnaire (PAQ-C) was used to evaluate the weekly physical engagement. Results: Ontogenetic multiplicative models suggested nonlinear associations with GMC across the children's developmental years. Linear physique was a significant predictor associated with the development of GMC across time. PAQ-C was significantly associated with GMC from 8 to 13 years old. Conclusion: Growth does not respect linear trends. A greater lean body mass could be assessed as a reliable predictor of GMC in children. The crucial period of life to improve the GMC is 8-10 years, while stabilization becomes evident from 10 to 13 years.

Elbow Joint Position and Force Senses in Young and Adult Untrained People and Gymnasts.

Joint position (JPS) and force senses (FS) are the proprioception modalities. While the development of JPS was investigated both in children/adult and athlete/untrained conditions, there is a lack of insight into the development of FS. Overall, 28 gymnasts and 25 untrained controls underwent proprioception testing. They were divided into two groups: 9 to 11-year-old boys (13 gymnasts and 10 non-athletes) and 18 to 25-year-old adults (15 gymnasts and 15 non-athletes). The testing was performed at an isokinetic dynamometer and included elbow JPS and FS (20% and 50% maximal voluntary contraction) tasks. Children had two times higher error in JPS (p < 0.01) and 50% higher errors in FS of both flexor (p < 0.001) and extensor muscles (p < 0.05) in comparison with adults. Only in the 50% maximal voluntary contraction task, gymnasts showed 33% lower error than the controls (p < 0.01). Untrained boys presented 54%, 132%, and 169% higher error for elbow flexor performance than young gymnasts, untrained adults, and adult gymnasts, respectively (p < 0.01). The 9 to 11-year-old participants were characterized by a lower precision of JPS and FS performance in comparison with adults. Gymnastic training can possibly accelerate the development of FS when higher loads are considered.

CCL2 Gene Expression and Protein Level Changes Observed in Response to Wingate Anaerobic Test in High-Trained Athletes and Non-Trained Controls.

Intensive, acute exercise may bring a large systemic inflammatory response marked by substantial increases in inflammatory cytokines and chemokines. One such chemokines-CCL2-is a key factor involved in inflammatory reaction to exercise. The direct aim of the study was to describe the changes in the CCL2 expression levels after anaerobic exercise in well-trained athletes adapted to long-term training and in non-trained participants. The expression of CCL2 mRNA was evaluated in peripheral blood MNCs and CCL2 protein level was observed in blood plasma. The changes were assessed as the response to an acute, intensive bout of exercise (Wingate Anaerobic Test) in two groups of participants: well-trained soccer players and non-trained individuals. An increase of CCL2 expression inn both mRNA and protein levels was observed. The response was greater in non-trained individuals and elevated levels of CCL2 transcripts persisted for more than 24 h after exercise. Well-trained individuals responded more modestly and the effect was attenuated relatively quickly. This shows muscular adaptation to a continuous training regime in well-trained individuals and better control of immune reactions to muscular injury. In non-training individuals, the induction of the inflammatory response was greater, suggesting presence of more serious myotrauma.

Direct Effects of Vitamin D Supplementation on Ultramarathon-Induced Changes in Kynurenine Metabolism.

In humans, most free tryptophan is degraded via kynurenine pathways into kynurenines. Kynurenines modulate the immune system, central nervous system, and skeletal muscle bioenergetics. Consequently, kynurenine pathway metabolites (KPMs) have been studied in the context of exercise. However, the effect of vitamin D supplementation on exercise-induced changes in KPMs has not been investigated. Here, we analyzed the effect of a single high-dose vitamin D supplementation on KPMs and tryptophan levels in runners after an ultramarathon. In the study, 35 amateur runners were assigned into two groups: vitamin D supplementation group, administered 150,000 IU vitamin D in vegetable oil 24 h before the run (n = 16); and control (placebo) group (n = 19). Blood was collected for analysis 24 h before, immediately after, and 24 h after the run. Kynurenic, xanthurenic, quinolinic, and picolinic acids levels were significantly increased after the run in the control group, but the effect was blunted by vitamin D supplementation. Conversely, the decrease in serum tryptophan, tyrosine, and phenylalanine levels immediately after the run was more pronounced in the supplemented group than in the control. The 3-hydroxy-l-kynurenine levels were significantly increased in both groups after the run. We conclude that vitamin D supplementation affects ultramarathon-induced changes in tryptophan metabolism.

Implications of Adipose Tissue Content for Changes in Serum Levels of Exercise-Induced Adipokines: A Quasi-Experimental Study.

Human adipocytes release multiple adipokines into the bloodstream during physical activity. This affects many organs and might contribute to the induction of inflammation. In this study, we aimed to assess changes in circulating adipokine levels induced by intense aerobic and anaerobic exercise in individuals with different adipose tissue content. In the quasi-experimental study, 48 male volunteers (aged 21.78 ± 1.98 years) were assigned to groups depending on their body fat content (BF): LBF, low body fat (<8% BF, n = 16); MBF, moderate body fat (8−14% BF, n = 19); and HBF, high body fat (>14% BF, n = 13). The volunteers performed maximal aerobic effort (MAE) and maximal anaerobic effort (MAnE) exercises. Blood samples were collected at five timepoints: before exercise, immediately after, 2 h, 6 h, and 24 h after each exercise. The selected cytokines were analyzed: adiponectin, follistatin-like 1, interleukin 6, leptin, oncostatin M, and resistin. While the participants' MAnE and MAE performance were similar regardless of BF, the cytokine response of the HBF group was different from that of the others. Six hours after exercise, leptin levels in the HBF group increased by 35%. Further, immediately after MAnE, resistin levels in the HBF group also increased, by approximately 55%. The effect of different BF was not apparent for other cytokines. We conclude that the adipokine exercise response is associated with the amount of adipose tissue and is related to exercise type.

Effect of 10 consecutive days of remote ischemic preconditioning on local neuromuscular performance.

BACKGROUND: Most studies focus on the effects of a single remote ischemic preconditioning (RIPC) session on performance. However, the training-like effect of repeat RIPC sessions performed on consecutive days could potentially be even more beneficial to neuromuscular performance than a single RIPC session. Therefore, aim of the study was to assess the impact of 10 days of RIPC on local neuromuscular performance. METHODS: Thirty-seven male participants performed 10 days of either RIPC or sham-controlled condition. Before and after procedure, the maximal voluntary contraction and muscle fatigue were assessed by dynamometry and surface electromyography (EMG) of the isometric extension of the knee joint. The following neuromuscular outcomes were investigated: peak torque (PKTQ); rate of force development (RTD); time to failure; and the slope of median frequency of power spectrum (MDF) and EMG amplitude. RESULTS: After RIPC, while there was no change in PKTQ and time to failure, the late RTD and MDF slope were significantly affected. The RTD at 0-100 and 0-200 ms showed 24 and 16% increase, respectively, while the MDF slope showed 24% decrease in rectus femoris. CONCLUSIONS: 10 days of RIPC induced neuromuscular performance changes in the quadriceps muscle. Even though there were no changes in task to failure performance, RIPC showed EMG changes limited to rectus femoris and increased late RTD in MVC task.

The Neuromuscular Characteristics of Gymnasts' Jumps and Landings at Particular Stages of Sports Training.

Safe and proper landings are crucial elements of gymnastics events. Long-term training leads to specific neuromuscular adaptations which are yet to be explored in terms of gymnastic landings. The aim of the study was to assess differences in landings' neuromuscular characteristics between gymnasts at three subsequent gymnastic training stages and age-matched non-athletes. Forty-six gymnasts (G) and 58 controls (C) performed countermovement jumps on a force plate with simultaneous surface electromyography (SEMG) of lower body muscles, measured during the pre-(100 ms) and post-landing phase (0-100 and 0-200 ms). Three age groups participated in the study: 8-10 (G1, C1), 12-14 (G2, C2), 18-25 (G3, C3) years. Analysis included the normalized root mean square (NRMS) SEMG signal and ground reaction forces (GRFs). Gymnasts achieved 13% higher values (p = 0.04) of relative peak GRFs in comparison with controls. It was especially seen in 8-10-year-olds: G1 presented 33% higher (p = 0.03) results than C1 and G2. In SEMG analysis, gymnasts showed overall lower NRMS values in comparison with the controls. In the pre-landing phase, the NRMS in the rectus femoris was from 1.6 up to 3.4 times higher for C1 (p = 0.02) than for C2, G2, C3, and G3. Gymnasts across subsequent training stages exhibit different patterns of neuromuscular coordination during landings. The highest GRF observed in the youngest gymnasts may be a potential risk factor of injuries. Therefore, further injury-focused investigation is recommended to monitor landing strategies among gymnasts of different stages with particular emphasis on the beginners.

cfDNA Changes in Maximal Exercises as a Sport Adaptation Predictor.

Changes of circulating free plasma DNA (cfDNA) are associated with different types of tissue injury, including those induced by intensive aerobic and anaerobic exercises. Observed changes are dependent from induced inflammation, and thus it may be a potential marker for athletic overtraining. We aimed to identify the response of cfDNA to different types of exercise, with association to exercise intensity as a potential marker of exercise load. Fifty volunteers (25 athletes and 25 physically active men) were assigned to the study and performed maximal aerobic (Bruce test) and anaerobic (Wingate Anaerobic Test) test. Blood samples for cfDNA analysis were collected at four time-points: before, 2-5 min after, 30 min after and 60 min after each type of maximal physical activity. The two-way ANOVA revealed a significant effect of group factor on serum cfDNA concentrations (32.15% higher concentration of cfDNA in the athletes). In turn the results of the post hoc test for the interaction of the repeated measures factor and the group showed that while the concentration of cfDNA decreased by 40.10% in the period from 30 min to 60 min after exercise in the control group, the concentration of cfDNA in the group of athletes remained at a similar level. Our analysis presents different responses depending on the intensity and duration of exercise. Our observations imply that formation of cfDNA is associated with response to physical activity but only during maximal effort.

Remote Ischemic Preconditioning Reduces Marathon-Induced Oxidative Stress and Decreases Liver and Heart Injury Markers in the Serum.

Clinical studies continue to provide evidence of organ protection by remote ischemic preconditioning (RIPC). However, there is lack of insight into impact of RIPC on exercise-induce changes in human organs' function. We here aimed to elucidate the effects of 10-day RIPC training on marathon-induced changes in the levels of serum markers of oxidative stress, and liver and heart damage. The study involved 18 male amateur runners taking part in a marathon. RIPC training was performed in the course of four cycles, by inflating and deflating a blood pressure cuff at 5-min intervals (RIPC group, n=10); the control group underwent sham training (n=8). The effects of RIPC on levels of oxidative stress, and liver and heart damage markers were investigated at rest after 10 consecutive days of training and after the marathon run. The 10-day RIPC training decreased the serum resting levels of C-reactive protein (CRP), alanine transaminase (ALT), γ-glutamyl transpeptidase (GGT), and malondialdehyde (MDA). After the marathon run, creatinine kinase MB (CK-MB), lactate dehydrogenase (LDH), cardiac troponin level (cTn), aspartate aminotransferase (AST), alkaline phosphatase (ALP), ALT, total bilirubin (BIL-T), and MDA levels were increased and arterial ketone body ratio (AKBR) levels were decreased in all participants. The changes were significantly diminished in the RIPC group compared with the control group. The GGT activity remained constant in the RIPC group but significantly increased in the control group after the marathon run. In conclusion, the study provides evidence for a protective effect of RIPC against liver and heart damage induced by strenuous exercise, such as the marathon.

Serum levels of bone formation and resorption markers in relation to vitamin D status in professional gymnastics and physically active men during upper and lower body high-intensity exercise.

PURPOSE/INTRODUCTION: To compare serum levels of bone turnover markers in athletes and non-athletes, and to evaluate the relationship between serum levels of vitamin D metabolites and exercise-induced changes in biomarker levels. METHODS: Sixteen elite male artistic gymnasts (EG; 21.4 ± 0.8 years-old) and 16 physically active men (the control group, PAM; 20.9 ± 1.2 years-old) performed lower and upper body 30-s Wingate anaerobic tests (LBWT and UBWT, respectively). For biomarker analysis, blood samples were collected before, and 5 and 30 min after exercise. Samples for vitamin D levels were collected before exercise. N-terminal propeptide of type I collagen (PINP) was analysed as a marker of bone formation. C-terminal telopeptide of type I collagen (CTX) was analysed as a marker of bone resorption. RESULTS: UBWT fitness readings were better in the EG group than in the PAM group, with no difference in LBWT readings between the groups. UBWT mean power was 8.8% higher in subjects with 25(OH)D3 levels over 22.50 ng/ml and in those with 24,25(OH)2D3 levels over 1.27 ng/ml. Serum CTX levels increased after both tests in the PAM group, with no change in the EG group. PINP levels did not change in either group; however, in PAM subjects with 25(OH)D3 levels above the median, they were higher than those in EG subjects. CONCLUSION: Vitamin D metabolites affect the anaerobic performance and bone turnover markers at rest and after exercise. Further, adaptation to physical activity modulates the effect of anaerobic exercise on bone metabolism markers.