The effect of space travel on human reproductive health: a systematic review.

With increasing possibilities of multi-year missions in deep space, colonizing other planets, and space tourism, it is important to investigate the effects of space travel on human reproduction. This study aimed to systematically review and summarize the results of available literature on space travel, microgravity, and space radiation, or Earth-based spaceflight analogues impact on female and male reproductive functions in humans. This systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and Space Biomedicine Systematic Review methods. The search was performed using three databases: PubMed, Web of Science, and Medline Complete. During the database search, 364 studies were identified. After the study selection process, 16 studies were included in the review. Five studies included female participants, and the findings show an increased risk of thromboembolism in combined oral contraceptive users, decreased decidualization, functional insufficiency of corpus luteum, and decreased progesterone and LH levels related to space travel or its simulation. Male participants were included in 13 studies. In males, reproductive health considerations focused on the decrease in testosterone and sex hormone-binding globulin levels, the ratio of male offspring, sperm motility, sperm vitality, and the increase in sperm DNA fragmentation related to space travel or its simulation. Results of this systematic review highlight the need to focus more on the astronaut's reproductive health in future research, as only 16 studies were found during the literature search, and many more research questions related to reproductive health in astronauts still need to be answered.

Effect of respiratory muscle endurance training on performance and respiratory function in professional cyclists during the off-season.

BACKGROUND: The study aimed to analyze the effect of respiratory muscle endurance training (RMT) on performance and respiratory function in professional road cyclists during the off-season period. METHODS: Twenty professional road cyclists from the Czech Republic were divided into the control (CON) (N.=10) and the RMT (N.=10) groups. Cyclists from the RMT group accomplished 30 sessions over 10 weeks. Performance in the incremental cycling test and respiratory capacity via test were assessed before and after 10 weeks in both groups. The comparison between and within the groups was performed, together with effect size and delta % (P<0.05). RESULTS: Significant effects on respiratory function during the exercise, on lung volume utilization at 90% of VO2max (TV-90%) and maximal voluntary ventilation (MVV) were found in RMT compared to the CON group, with a moderate effect size (0.71 and 0.61), and improvements of 13% and 14%, respectively. Parameters of performance in the cycling protocol and respiratory function at rest presented better values in the RMT group, however with no significance and in minor magnitude. CONCLUSIONS: Using RMT during off-season benefits professional road cyclists by improving the major efficiency of respiratory function during progressive efforts. Therefore, the protocol of RMT could be used as an ergogenic aid during this period in order to maintain respiratory adaptations, optimizing the pre-season training. Adjustments can be made to improve the parameters outcomes.

Load Carrying Walking Test for the Special Operation Forces of the Army of the Czech Republic.

INTRODUCTION: The subject of this study was the creation of a new type of laboratory walking stress test for the Special Forces of the Army of the Czech Republic. This study developed a test model that has been validated in practice and that reflects the fact that the performance of endurance without and with a load varies considerably. Especially, if we focus on operators, as their activities are always performed with loads/full gear (equipment, weapons, equipment, etc.). MATERIALS AND METHODS: 24 men/operators from the Special Forces of the Army of the Czech Republic volunteered for this study. The maximal exercise test/spiroergometry was designed to include performance at a load of 55 kg/121 lb, a constant speed of 5.3 km/h, and an increase in incline angle of 1 degree after each elapsed minute. The test was performed on a treadmill under standard time, location, and temperature conditions. During the test, the following values were recorded: VO2 = oxygen consumption indicating the intensity of the exercise was monitored, VO2/kg = oxygen consumption converted to body weight, VO2/HR = pulse oxygen (the amount of oxygen converted in one heartbeat), HR = heart rate, VE = ventilation, volume of air exhaled in 1 min, breathe frequency (BF) = respiratory rate in 1 min. RESULTS: Out of the total number of 24 respondents, the study found these mean values of variables. The variable mapping the oxygen consumption, which indicates the intensity of VO2 loading, was 3.8, with the lowest value being 3.2 and the highest being 4.5. After converting oxygen consumption to bodyweight, VO2/kg was 46, the lowest value of 38.8, and the highest 53.0 were measured for this variable. Pulse oxygen, i.e., the amount of oxygen calculated per heart contraction VO2/HR, was 20.5, the lowest value 16.0, and the highest 26.0. The average HR heart rate was 183.5, with the lowest value being recorded at 164 and the highest value is 205. Ventilation, i.e., the amount of exhaled air per minute in VE, was measured at 144.9, the lowest value was 114.7, and the highest was 176.6. The BF in 1 min was 58.5, the lowest value 35, and the highest 70. The mean time load was 10:20 min, the shortest test length was 7:25 min, and the longest was 13:23 min. These values correspond to the degree of inclination of the ascent, i.e., the mean value was 10 degrees, the smallest achieved slope was 7 degrees, and the largest 13 degrees. CONCLUSION: The designed weighted walking test proved to be fully functional and effective in measurement. The further established protocol corresponds to the requirements of the current needs of the Special Forces of the Army of the Czech Republic. Last but not least, the walking stress test is applied for the external and internal selection and screening of operators. Data obtained from testing were used to develop deployment requirements for patrol/nuclear combat missions.

The Prevalence of Menstrual Cycle Disorders in Female Athletes from Different Sports Disciplines: A Rapid Review.

The aim of this study was to rapidly review the literature on the prevalence of menstrual disorders in female athletes from different sports modalities. Articles were searched in the Web of Science and PubMed database in May 2022. A total of 1309 records were identified, and 48 studies were included in the final stage. The menstrual disorders described in the included studies were primary (in 33% of included studies) and secondary amenorrhea (in 73% of included studies) and oligomenorrhea (in 69% of included studies). The prevalence of menstrual disorders among the studies ranged from 0 to 61%. When data were pooled according to discipline (mean calculation), the highest prevalence of primary amenorrhea was found in rhythmic gymnastics (25%), soccer (20%) and swimming (19%); for secondary amenorrhea in cycling (56%), triathlon (40%) and rhythmic gymnastics (31%); and oligomenorrhea in boxing (55%), rhythmic gymnastics (44%) and artistic gymnastics (32%). Based on the results of this review, the study supports the literature of the higher prevalence of menstrual disorders in gymnastics and endurance disciplines. However, team sports modalities such as volleyball and soccer also presented a considerable percentage of menstrual disorders compared to the general population. It reinforces the importance of coaches and physicians paying attention to athletes' menstrual cycle as the occurrence of menstrual disorders can be associated with impairment on some health components.

Preventing chronic fatigue in Czech young athletes: The features description of the "SmartTraining" mobile application.

This study describes a beta version of a mobile application (app) that focuses on preventing chronic fatigue in Czech youth athletes. The first version of the SmartTraining app was developed for athletes as a way to prevent chronic fatigue via alertness and education. For alertness, a multistage process was developed using a combination of parameters about training responses, such as tiredness, well-being, heart rate, energy balance and psychological, and health-related aspects. According to the combination of the multistage parameter outcomes, the algorithm classifies the risk of fatigue based on semaphore light: green corresponds to low, yellow to moderate and red to high risk. The education presented in the app consisted of written and "animated videos" material about the variables involved in training, such as training demands and athletes' responses, regeneration, nutrition and communication between athletes, coaches, and parents. Subsequently, a beta version of the app was created and freely available to download for Android or iOS mobile. The app can be used in daily routines to reduce the risk of chronic fatigue from inadequate training dose response. Prevention can minimise the risk of injury or physical and emotional burnout in youth. Informing athletes on how to carefully handle the training factors can improve athletes' awareness of their performance and health status. Collaboration between sports scientists and the commercial sector allows for the efficient development of an easy-to-use and low-cost tool for use in sports settings. Future steps should be performed to validate the app's accuracy in its alertness and in the efficiency of the educational process.

Pre-competitive anxiety and autonomic responses in professional U-20 futsal players: Effect of the competition phase and game location.

The study examined whether pre-competition anxiety and autonomic responses in elite futsal players change across the playoffs at away vs home venues. Heart rate variability, somatic and cognitive anxiety and self-confidence (by CSAI-2R questionnaire) were evaluated in nine male futsal players from a professional U-20 team, before competitive matches at the quarter-final, semi-final and final stages played at home and away venues. Two-way ANOVA for repeated measures was used, considering factor one the game location and factor two the playoff stage, with significance set at p<0.05. Significant effects of the playoff stage were demonstrated in the Mean of HR (F = 4.643; p = 0.014) and SD2 index (F = 14.83; p=<0.001)(quarter versus final). No difference was found for somatic and cognitive anxiety and self-confidence between the two factors. The results suggest that play at the final stage of the playoff, regardless of the game location, may cause higher physiological stress, demonstrated by elevated HR and decrease of SD2 index.

Thermographic evaluation of muscle activity after front crawl swimming in young men.

PURPOSE: The information about the workload on individual muscles in the course of a specific physical activity is essential for targeted prevention, early diagnosis and suitable therapy concerning their overloading and injury. The aim of this study is to evaluate temperature changes in particular skin areas in the course of front crawl swimming, caused by muscle work. METHODS: Thermograms were taken of 13 students of Defense University immediately and 15 minutes after swimming 1,000 m focused on 20 regions of the skin over the selected agonists and synergists in upper extremities and body. FLUKE TiR infrared hand camera was used. RESULTS: The results indicated the significant increase in the relative temperatures in the areas of agonists of swimmers' movement - triceps brachii: from 0.952 to 0.997 of normalized units (nu) on the right and from 0.955 to 0.986 nu on the left. At the same time, the temperature of the muscles participating in lifting the arms above the water surface and stretching them forward - deltoids - increased as well (rear part: from 1.002 to 1.015 nu on the right and from 1.002 to 1.014 nu on the left, sides: from 1.008 to 1.023 nu on the right and from 1.011 to 1.023 nu on the left). CONCLUSIONS: In conclusion, the order of the other agonists is as follows: biceps brachii, pectoralis major muscle, and latissimus dorsi. This study provides the options for objective assessment of workload on specific muscles or muscle groups during front crawl swimming.

Anthropometric characteristics and body bomposition in aikido practitioners / Características antropométricas y composición corporal en practicantes de aikido

Although aikido is a non-competitive martial art, it is recognised by SportAccord as worldwide practiced combat sport. There is a lack of scientific research in aikido and the influence of aikido practice on the human body is not known. This is the first study that presents anthropometric characteristics and body composition data in aikido practitioners. 33 adult male aikido athletes (age 36.5±9.6 years, height 178±8 cm, weight 81.2±10.1 kg) were measured. All subjects were divided from beginner to intermediate and advanced group, and were recruited from the Czech Aikido Federation which is officially recognised by the centre of aikido in Japan. As main methods, bio impedance and skinfold measurements were realized. In aikido, body composition does not play an important role compared to other martial arts. Average values are similar to reference of non-athlete population (BMI 25.6±2.7 kg/m, BF 17.18±5.18 %, FFM 65.71±7.69 kg, BSA 1.98±0.15 m2). Even though, aikido has positive effects on body composition, it does not have a high impact. Thus, aikido players should also gain benefits from other aspects of martial arts.

A pesar de que el aikido es un arte marcial no competitivo, es reconocido por SportAccord como un deporte de combate practicado en todo el mundo. Existe escasa investigación científica sobre el aikido y la influencia de su práctica en el cuerpo humano. Este es el primer estudio que presenta las características antropométricas y datos de composición corporal en practicantes de Aikido. Se midieron 33 hombres adultos, atletas de aikido (edad 36,5±9,6 años, altura 178±8 cm, peso 81,2±10,1 kg). Los sujetos fueron divididos en los grupos: principiante, intermedio y avanzado, reclutados desde la Federación Checa de Aikido, que es reconocida oficialmente por el centro de aikido en Japón. Como métodos principales, se realizaron mediciones de bioimpedancia y pliegues cutáneos. En el aikido, la composición corporal no juega un rol importante en comparación con otras artes marciales. Los valores promedio fueron similares en comparación a valores de la población no deportista (IMC 25,6±2,7 kg/m, BF 17,18±5,18 %, FFM 65,71±7,69 kg, BSA 1,98±0,15 m2). A pesar de que el aikido tiene efectos positivos en la composición corporal, no tiene un alto impacto. Por lo tanto, los atletas de aikido deberían también obtener beneficios de otros elementos de las artes marciales.

The influence of breaststroke swimming on the muscle activity of young men in thermographic imaging.

The aim of this work is to describe and assess energetic-metabolic activity of selected muscles of upper extremities and body during breaststroke swimming through infrared thermography as electromyography cannot display such muscle activity. Thermograms were taken of 25 students from the University of Defence immediately and 15 minutes after swimming 1,000 m focused on 20 regions of interest, i.e., corresponding to selected agonists and synergists in upper extremities and body. We used FLUKE TiR infrared hand camera. It was found that there is a significant increase (normalized units) 15 minutes after swimming in triceps brachii (on the right prior to swimming 0.950 and after swimming 0.994; on the left prior to swimming 0.947 and after 0.990), and in side, rear and front parts of the deltoid muscles. On the contrary, there was a significant relative decrease in temperature in pectoralis, rhombic and lower trapezius, erector spinae lumbalis and latissimus dorsi. It can be concluded that swimming 1,000 m breaststroke affected significant increase in the temperature of regions of interest, i.e., corresponding to agonists and synergists of upper extremities for the swimmer's forward motion. A relative decrease in temperature occurred rather in body muscles. The problem of biased results due to water cooling was solved by using thermograms taken only in the 15th minute after getting out of water and calculating relative temperatures with normalized units.