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The human organism is affected by multiple stressors every single day, especially during extremely demanding activities. It needs a method to regulate itself better. One of the stressors that is affecting humans is social isolation. The state of prolonged isolation happens during space missions. In this study, 40 analog astronauts attended a two-week-long mission. The experimental group had EEG neurofeedback training intervention performed on a daily basis, while the control group remained isolated without neurofeedback. The results let us take this non-invasive intervention under consideration, while debating the methods to lower the physiological stress reaction in humans that are exposed to extremely hard circumstances. Although not statistically significant, the trends observed give us direction towards other research to confirm EEG neurofeedback as a method to lower cell stress response levels.

Background: The human body is exposed to stressors on a daily basis. Short-term exposure to a particular stressor can cause the release of inflammatory markers - including c-reactive protein (CRP). EEG neurofeedback is a noninvasive form of therapy that aims to improve brain function. Neurofeedback is a type of feedback based on brain activity., Methods: The research process was performed by a group of 80 men who were divided into 2 research groups and 2 control groups. In the first research group and the first control group, the stressor of high temperature was applied, while in the second research group and the second control group, the stressor was physical exertion to refusal. Meanwhile, blood samples were taken to visualize inflammatory markers. These were taken before and after the stressor, as well as before and after the application of EEG neurofeedback., Results: In research group after EEG neurofeedback intervention, the level of CRP significantly dropped in the measurement after stressor implementation. Analysis of the SMK test revealed a significant influence of both factors (time F = 13.525, P = .035; state F = 10.658, P = .047) and their interaction (F = 16.709, P = .026). Same statically significant decrease was observed in the level of rect. abdom. EMG was after physical work after neurofeedback. In all tests, a decrease in the EMG amplitude of upper trap. was observed after physical work before neurofeedback with its further increase after neurofeedback. After neurofeedback training, the results of the 3 tested parameters of the sensorimotor coordination test performed after the second heat stressor improved statistically insignificantly compared to the values obtained before., Conclusion: This article shows the effect of EGG neurofeedback on reducing the negative effects of stress exposure in humans. The study showed that the level and a pattern of EEG neurofeedback influence and significance is different depending on the applied stressor. Furthermore, the level of EEG neurofeedback influence and significance in decreasing the stressor effect is different depending on the examined sphere., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

The aim of the current study is to determine how the level of state and trait anxiety differs between youth athletes of different performance levels and furthermore whether there are correlations between performance levels and psychomotor variables in the selected tasks. A sample of 97 boys, aged 11-12 years, practising soccer represented two groups: A - high performance level and B - lower performance level. Participants completed a state and trait anxiety inventory and performed selected psychomotor tests. The analyses demonstrated that the higher the levels of anxiety were, the shorter was the response time and more accurate were the responses in selected psychomotor tests. For the whole group, r = -0.224, p < 0.05, and for group B, r = -0.333, p < 0.05. Moreover, the findings showed a moderator effect of level (group A vs B) on reaction time, which was almost significant in state anxiety and significant in trait anxiety. For group B, trait anxiety was negatively related to reaction time (b = -0.002, SE = 0.001, t = -2.93, p = .004, 95% CI [-0.004, -0.001]). This means that the higher the trait anxiety was, the shorter was the reaction time in group B, but there was no significant effect in group A. The results of the study confirmed the negative correlation between the trait and state anxiety and reaction time. The higher the anxiety was, the shorter was the response time of child soccer players. Future research should determine whether athletes' performance levels do affect performance under stress and replicate the study with different samples such as girls and different sport disciplines., Competing Interests: There is no conflict of interests between the authors., (Copyright © Biology of Sport 2022.)

Purpose: Previous investigations have found positive effects of acute ingestion of capsules containing 4-to-9 mg of caffeine per kg of body mass on several aspects of judo performance. However, no previous investigation has tested the effectiveness of caffeinated chewing gum as the form of caffeine administration for judoists. The main goal of this study was to assess the effect of acute ingestion of a caffeinated chewing gum on the results of the special judo fitness test (SJFT)., Methods: Nine male elite judo athletes of the Polish national team (23.7 ± 4.4 years, body mass: 73.5 ± 7.4 kg) participated in a randomized, crossover, placebo-controlled and double-blind experiment. Participants were moderate caffeine consumers (3.1 mg/kg/day). Each athlete performed three identical experimental sessions after: (a) ingestion of two non-caffeinated chewing gums (P + P); (b) a caffeinated chewing gum and a placebo chewing gum (C + P; ~2.7 mg/kg); (c) two caffeinated chewing gums (C + C; ~5.4 mg/kg). Each gum was ingested 15 min before performing two Special Judo Fitness Test (SJFT) which were separated by 4 min of combat activity., Results: The total number of throws was not different between P + P, C + P, and C + C (59.66 ± 4.15, 62.22 ± 4.32, 60.22 ± 4.08 throws, respectively; p = 0.41). A two-way repeated measures ANOVA indicated no significant substance × time interaction effect as well as no main effect of caffeine for SJFT performance, SJFT index, blood lactate concentration, heart rate or rating of perceived exertion., Conclusions: The results of the current study indicate that the use of caffeinated chewing gum in a dose up to 5.4 mg/kg of caffeine did not increase performance during repeated SJFTs.

Background: Pregnancy and high impact exercise may cause postnatal urinary incontinence. We aimed to evaluate the life impact of postnatal urinary incontinence in women attending prenatal, high-low impact exercise program, supported by pelvic floor muscle education and training, in comparison to controls., Methods: It was a quasiexperimental trial among 260 postpartum Caucasian women (age 29 ± 4 years; mean ± standard deviation). The training group (n = 133) attended a high-low impact exercise and educational program from the 2nd trimester of pregnancy until birth, 3 times a week. We educated this group to contract and relax pelvic floor muscles with surface electromyography biofeedback and instructed how to exercise postpartum. Control women (n = 127) did not get any intervention. All women reported on the life impact of urinary incontinence 2 months and 1 year postpartum using the Incontinence Impact Questionnaire (IIQ)., Results: Training group started regular pelvic floor muscle exercises substantially earlier postpartum than controls (P < .001). Significantly less training women reported the life impact of urinary incontinence both 2 months (P = .03) and 1 year postpartum (P = .005). Two months after birth, for the symptomatic women the IIQ scores were significantly lower in the training than in the control women (median [Me] = 9.4 vs Me = 18.9; P = .002). Between the 1st and 2nd assessments the number of women affected by incontinence symptoms decreased by 38% in the training group and by 20% in the controls., Conclusion: High-low impact activities supported by pelvic floor muscle exercises and education should be promoted among pregnant, physically active women. Such activities may help women to continue high-intensity exercise with the simultaneous prevention of postnatal urinary incontinence.Thy study was registered at ISRCTN under the title "Pelvic floor muscle training with surface electromyography" (DOI 10.1186/ISRCTN92265528).

A quick, well-timed pelvic-floor muscle contraction during physical effort is recommended for active women to prevent urine leakage., Purpose: We address two research questions: how well do future female exercise professionals contract the pelvic-floor muscles, and whether the biofeedback session is necessary to train them to contract pelvic-floor muscles?, Method: Participants were 84 nulliparous future exercise professionals (age 23 ± 3 years, mean ± SD), randomly allocated into biofeedback ( n = 27), usual-advice ( n = 26), and control (no advice, n = 21) groups. Contraction of pelvic-floor muscles on a 4-point scale (1 = incorrect through 4 = correct) was assessed in all groups by surface electromyography (sEMG) with a vaginal probe before and after 6 weeks of intervention., Results: In pretest, almost one in five participants (17%) could not activate the pelvic floor and less than half of them (45%) presented correct technique. The technique score for the three groups was 3.1 ± 1.1 (mean ± SD). After training, both intervention groups presented better technique score by 0.6 (90% confidence limits ± 0.5) relative to the control group, and two-thirds (65%) of the intervention groups presented the correct technique., Conclusions: Future exercise professionals displayed poor skills in contracting pelvic-floor muscles. Both training interventions (with and without biofeedback) were effective for this study group.

Objectives: Anxiety is a negative emotion that acts as a mediator between stress stimuli and emotional (physiological) reaction patterns. The myofascial system is particularly sensitive to stress. The aim of this study was to determine which of the 2 popular methods used to reduce psychophysical tension, i.e., soft tissue manipulation and Jacobson's progressive relaxation, is more effective., Material and Methods: This study was conducted at Gdansk University of Physical Education and Sports in the sports psychology laboratory and the manual therapy room. After performing specialist consultations and interviews to exclude potential participants with contraindications to any of the interventions, the final sample included 90 people who were randomly assigned to 1 of 2 treatment groups. In group I, soft tissue techniques were applied, including the techniques of post-isometric muscle relaxation, elements of myofascial relaxation of tissues, and elastic tissue deformation using the Swedish massage limited to the cervicothoracic complex. In group II, Jacobson's progressive relaxation was performed. The training consisted of tightening and relaxing specific muscle groups. The experiment was conducted under an ambulatory condition, consisting of a single physiotherapeutic session (group I) or a single progressive relaxation session using the Jacobson method (group II). The level of anxiety was assessed twice, i.e., immediately before and after the therapy., Results: According to a repeated-measures ANOVA, each therapeutic impact was effective in reducing the level of perceived anxiety. Furthermore, the level of perceived anxiety in group I decreased significantly more than that in group II., Conclusions: In conclusion, both the soft tissue manipulation and Jacobson's progressive relaxation techniques were efficient methods of minimizing the negative effects of stress. Int J Occup Med Environ Health. 2019;32(6):817-24., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Pickering, C, Suraci, B, Semenova, EA, Boulygina, EA, Kostryukova, ES, Kulemin, NA, Borisov, OV, Khabibova, SA, Larin, AK, Pavlenko, AV, Lyubaeva, EV, Popov, DV, Lysenko, EA, Vepkhvadze, TF, Lednev, EM, Leońska-Duniec, A, Pająk, B, Chycki, J, Moska, W, Lulińska-Kuklik, E, Dornowski, M, Maszczyk, A, Bradley, B, Kana-ah, A, Cięszczyk, P, Generozov, EV, and Ahmetov, II. A genome-wide association study of sprint performance in elite youth football players. J Strength Cond Res 33(9): 2344-2351, 2019-Sprint speed is an important component of football performance, with teams often placing a high value on sprint and acceleration ability. The aim of this study was to undertake the first genome-wide association study to identify genetic variants associated with sprint test performance in elite youth football players and to further validate the obtained results in additional studies. Using micro-array data (600 K-1.14 M single nucleotide polymorphisms [SNPs]) of 1,206 subjects, we identified 12 SNPs with suggestive significance after passing replication criteria. The polymorphism rs55743914 located in the PTPRK gene was found as the most significant for 5-m sprint test (p = 7.7 × 10). Seven of the discovered SNPs were also associated with sprint test performance in a cohort of 126 Polish women, and 4 were associated with power athlete status in a cohort of 399 elite Russian athletes. Six SNPs were associated with muscle fiber type in a cohort of 96 Russian subjects. We also examined genotype distributions and possible associations for 16 SNPs previously linked with sprint performance. Four SNPs (AGT rs699, HSD17B14 rs7247312, IGF2 rs680, and IL6 rs1800795) were associated with sprint test performance in this cohort. In addition, the G alleles of 2 SNPs in ADRB2 (rs1042713 & rs1042714) were significantly over-represented in these players compared with British and European controls. These results suggest that there is a genetic influence on sprint test performance in footballers, and identifies some of the genetic variants that help explain this influence.

Objectives: The aim of this study was to discover the relationship between the performance of different mechanical movements of rowers, and define its effect on the motor programs of the cyclic movement in athletes living in rural and urban areas., Material and Methods: Twenty-two male rowers participated in the experiment using a rowing ergometer (Concept2, USA). The experiment consisted of 3 tests examining the maximal power of the pull-ups (MPbpu). The movement mechanogram was registered with a specialized complex Noraxon's 3D MyoMotion (Noraxon Inc., USA). The software of the complex allowed calculation of the values of the joint angles from the accelerometer data. The Origin Lab 8.5 program was used for the mathematical and statistical processing of the signals from the mechanograms., Results: It was found that all experiment participants had a stepped controlled increase in the power of single bar pull-ups leading to a corresponding proportional increase in the frequency of rowing - test 1 and, conversely, a stepped controlled increase in the rowing frequency accompanied by a proportional increase in the power of the bar pull-ups - test 2. The involuntary dependence of the power and the rate was due to the peculiarities of the central cyclic movement programming, according to which the forces and durations of the active and passive bar pull-ups phases were interconnected and regulated together. The voluntary power-rate dependence control led to the breakdown of these links in the motor program of cyclic movements and to the separate control of these parameters., Conclusions: Motor programs in cyclic movement may be created in the same pattern in tope level sport and recreation, as well in different environmental conditions - gym halls (movement simulators), professional and recreational water sport tracks.

This study examined the effects of different training loads on pelvic floor muscle (PFM) activity in swimming. Twelve female swimmers were included in this study (23.71±1.44 y.o.; 167±5.89 cm; 62.05±8.89 kg). They took part in an experiment with two different stages of load in swimming training. For the pelvic floor muscle assessment the Glazer Protocol was used. To assess swimming technique, David Pyne's Stroke Mechanics Test was used. A statistically significant increase in surface electromyography (sEMG) values appeared in the fifth R (rest after contraction) in the quick flick stage of the measurement protocol of PFM at the third measurement time (7.71±4.49 μV) compared to the first measurement time (6.25±4.43 μV) with p≤0.05. Increasing the training load may cause unwanted changes in the level of electrical activity of pelvic floor muscles., Competing Interests: The authors declare no conflict of interest including any financial, personal or other relationships.

Background: Pregnancy and high-impact activity are considered as risk factors for pelvic floor dysfunctions, including urinary incontinence. Aim: To investigate whether a structured exercise program, including high- and low-impact aerobics and supported by pelvic floor muscle exercises, improves the neuromuscular activity of the pelvic floor and does not reduce the quality of life in terms of urinary incontinence in healthy pregnant women. Methods: This was a randomized control trial among 97 Caucasian healthy nulliparas in uncomplicated pregnancies (age 30 ± 4 years, 21 ± 5 weeks of gestation; mean ± SD). Women were assessed for pelvic floor muscle functions with surface electromyography (EMG) using vaginal probes and using the Incontinence Impact Questionnaire (IIQ). Only women able to contract pelvic floor muscles and with good quality of life based on IIQ were included for the study. Seventy women in the experimental group took part in a supervised exercise program including high-low impact aerobics and pelvic floor muscle exercises three times a week. Twenty-seven controls did not receive any exercise intervention. After 6 weeks both groups were re-tested with EMG and IIQ. Post- and pre-exercise program changes in each group were analyzed using a repeated-measures ANOVA. Results: Women in the experimental group improved the neuromuscular activity of the pelvic floor in some motor tasks without any adverse outcomes of the intervention. After the exercise program we observed in the experimental group significantly higher EMG amplitude in the pelvic floor muscles during 3-s contractions ( p = 0.014). We also noticed a beneficial trend in the increase of neuromuscular activity during 10- and 60-s contractions, but the changes were not statistically significant. The exercising women substantially improved their abilities for relaxation following 3- and 10-s contractions ( p = 0.013 and p < 0.001). In controls, we reported no statistically significant improvement in either of the motor tasks. All study participants maintained good quality of life related to urinary incontinence. Conclusion: Prenatal exercise programs that include high- and low-impact aerobics and are supported by pelvic floor muscle exercises should be recommended for pregnant women, especially those who are accustomed to higher exercise intensity before pregnancy. Nevertheless, these recommendations can be directed to continent women who can properly contract pelvic floor muscles. ISRCTN. DOI: 10.1186/ISRCTN92265528: "Pelvic floor muscle training with surface electromyography", retrospectively registered on the 25th of July, 2016.

Endothelial nitric oxide synthase (NOS3) generates nitric oxide in blood vessels and is involved in the regulation of vascular function, metabolism and muscle fibre type transformations. Evidence suggests that the NOS3 G894T (rs1799983) and -786T/C (rs2070744) polymorphisms are associated with athletic performance. The purpose of this study was to determine the association between the NOS3 G894T and -786T/C polymorphisms with elite swimmer status in Polish athletes. One hundred and ninety-seven Polish swimmers (104 males and 93 females), who competed in national and international events, and 379 healthy control subjects (222 males and 157 females) were recruited for this study. The swimmers were divided into two groups: short distance swimmers (SDS; n=147; 50-200 m) and long distance swimmers (LDS; n=49; more than 500 m). As expected, the frequencies of the -786T/C T allele (77.0 vs. 63.1%, p = 0.0085) and G-T haplotype (63.7 vs. 52.0, p=0.025) were significantly higher in the LDS group in comparison with controls. Compared with the -786T/C CC genotype, the chance of being a long distance swimmer was 8.49 times higher (CI=1.14-62.78, p=0.023) for the carriers of -786T/C T allele than in control subjects. On the other hand, the Asp allele frequency was significantly higher in the female SDS group compared with controls (34.3 vs. 18.5%, p=0.00043). In conclusion, our results demonstrate that the T allele and the G-T haplotype of the -786T/C and G894T polymorphisms may be beneficial for long distance swimmers.

BACKGROUND Pelvic floor muscle exercises are a widely used and well-established form of stress incontinence treatment, with success rates varying from 21% to 84%, although with a better subjective than objective outcome. MATERIAL AND METHODS "Incontinence Impact Questionnaire" (IIQ), PFM EMG assessment was done at the beginning and after the 6-week training program. RESULTS Statistically significant differences appeared in the BASE and R values. In the symptomatic group (with SUI symptoms), the value of BASE was 3.26 µV, and after training it was 3.95 µV. The R values before and after training were 4.55 µV and 4.25 µV. In the symptomatic group (without SUI symptoms), the value of BASE was 2.88 µV and 3.52 µV and R values were 7.16 µV and 3.92 µV. In the control group, BASE was 3.05 µV and 4.11 µV and R was 7.82 µV and 4.39 µV. CONCLUSIONS The results indicate that a 6-week training process influences PFM EMG activity in pregnant women. During Q, the value of PFM activity after a training session tended to increase in the symptomatic and control groups, but in the symptomatic group it remains practically unchanged. Our results show the probable process of decreasing control of PFM activity during long-lasting contractions in symptomatic and control women. The comparison of BASE before and after training averaged the values of R after five 10-s contractions and showed an increase in the Base and decrease in the R.

Among genetic variants of the ADIPOQ gene +276 G>T (rs1501299) and -11377 G>C (rs266729) are the most frequently investigated polymorphisms which were described in the context of genetic conditioning for a predisposition to obesity. However, the information of polymorphisms' potential modifying effect on obesity-related traits achieved through training procedures are still unknown. DNA was extracted from buccal cells donated by the 201 participants and genotyping was carried out using real-time PCR. The genotype distribution was examined in a group of women measured for chosen traits before and after the completion of a 12-week training programme. Our results suggest that the ADIPOQ genotypes analyzed individually or in combination can modulate training-induced body mass measurements changes: after the training programme, carriers of rs1501299 T allele and rs266729 C allele were characterized by a greater reduction in fat mass percentage (FM), fat mass, and body mass. Moreover, the ADIPOQ polymorphisms were associated with changes in lipid profile in response to training. Additionally, we showed three main effects of genotypes for the FM, LDL-C (rs266729), and TBW (rs1501299). Our study indicate that the both polymorphisms are associated with changes in obesity-related traits in response to 12-week aerobic training programme in Caucasian women. From this evidence, it could be concluded that rs1501299 G and rs266728 G variants may be considered as disadvantageous factor in the context of training-induced effects on body mass traits., Competing Interests: No conflicts of interest, financial or otherwise, are declared by the authors.

Background: One of the aims of the study was to describe the physiological factors of young boys participating in artistic gymnastic training and evaluate differences between the levels of aerobic and anaerobic efficiency in this group as compared to the control group., Methods: The young male gymnasts selected to participate in the present study have been (G) participating in the training process since they were 6 years old (N.=12, age 11-12 y). In the control group (N.=12, age 11-12 y), boys were participating in physical education classes (C). Anaerobic efficiency was evaluated by using a 30 s Wingate Anaerobic Test (WAnT) for arms. Adjusted load was defined on the level of 50 g·kg-1 of body mass. Aerobic efficiency was defined using gradual effort to exhaustion for lower limbs on the cycle ergometer with simultaneous analysis of breathing gases., Results: The test to exhaustion showed that group G achieved lower VO2peak results as compared to group C. The values were respectively: 48.1 mL·kg-1·min-1 and 55.6 mL·kg-1·min-1 (P<0.05). In the examination of anaerobic efficiency for upper limb parameters, total work and mean power were higher in group G than in group C, while the fatigue index (FI) was lower., Conclusions: It is likely that early specialization in young male gymnasts may influence proper aerobic metabolism development. Executing WAnT using arms in group G was more convenient and precise according to anaerobic efficiency.

Slow circular movements of the hand with a fixed wrist joint that were produced in a horizontal plane under visual guidance during conditions of action of the elastic load directed tangentially to the movement trajectory were studied. The positional dependencies of the averaged surface EMGs in the muscles of the elbow and shoulder joints were compared for four possible combinations in the directions of load and movements. The EMG intensities were largely correlated with the waves of the force moment computed for a corresponding joint in the framework of a simple geometrical model of the system: arm - experimental setup. At the same time, in some cases the averaged EMGs exit from the segments of the trajectory restricted by the force moment singular points (FMSPs), in which the moments exhibited altered signs. The EMG activities display clear differences for the eccentric and concentric zones of contraction that are separated by the joint angle singular points (JASPs), which present extreme at the joint angle traces. We assumed that the modeled patterns of FMSPs and JASPs may be applied for an analysis of the synergic interaction between the motor commands arriving at different muscles in arbitrary two-joint movements.

The features of the formation of targeted tonic isometric effort created by muscles of the shoulder girdle and shoulder were compared for two opposite changes of the directions of arbitrary force vector-clockwise and counterclockwise. The magnitude of the effort vector remained constant. The intensity of the central motor commands (CMC) was evaluated according to the area of founded rectified, averaged and approximated electromyographic (EMG) recorded from the investigated muscles. The effort development was carried out in determined direction in operation space of the horizontal plane under angles of 75 degrees in the shoulder joint and 90 degrees in the elbow one. The synergic interaction of individual functional groups of muscles under certain reaction force was found. In the case of space, it was determined the main activity areas of the investigated muscles within the operating space. The differences were shown in the levels of EMG amplitude in opposite directions bypass of effort vector. Coactivation of flexor muscles was found, while the extensors showed their activity only within their functional sectors. Half of the investigated muscles showed an increase of the EMG amplitude for the counter-clockwise direction in relation to EMG amplitude for the clockwise direction. This can be attributed to more complex patterns of motor commands organization which consistently addressed to the muscles of the shoulder and forearm caused by atypical sequence of activation of antagonist muscles under making hand movements in cyclic mode during tonic isometric contraction.