Agreement and differences between the equations for estimating muscle and bone mass using the anthropometric method in recreational strength trainees.

Introduction: The interest in estimating muscle mass (MM) and bone mass (BM) has grown in the sporting arena, and more specifically in recreational strength trainees, leading to the creation of different strategies to assess them. The aims were: 1) to investigate the agreement between different MM and BM formulas, and the muscle-bone index (MBI), and to establish the differences between them, in a healthy young adult population; and 2) to analyze if there are differences between males and females in the comparison of MM, BM and MBI formulas. Methods: This study followed a descriptive cross-sectional design. A total of 130 adult active recreational strength trainees were evaluated according to the procedures described by the International Society for the Advancement in Kinanthropometry (ISAK). Estimations were made in kilograms of MM and BM by following the equations by different authors. Results: The results showed significant differences between the values obtained by all the MM and BM formulas in the general sample (p < 0.001), and by the majority of formulas for male and female samples. In the general sample, Lin's coefficient indicated a strong agreement between Kerr, Lee, and Poortmans' MM estimation equations (concordance correlation coefficient (CCC) = 0.96-0.97). However, when stratifying by sex, this agreement persisted only in males (CCC = 0.90-0.94), in contrast with a lack of agreement observed in females (CCC < 0.90). Discrepancies in bone mass agreement were noted both in the general sample (CCC < 0.15) and when stratified by sex (CCC < 0.12). Conclusions: In general, differences were found between the values reported by the MM and BM formulas in recreational strength trainees, without an agreement between them. Sex was shown to significantly influence the differences found. The practical implications are that when comparing an individual with reference tables, other studies, or if analyzing an individual's evolution, the same estimation equation should be used, as they are not interchangeable.

Are physical activity and/or adherence to the Mediterranean diet determinants of the changes found in kinanthropometric variables, body composition and physical fitness in adolescents?

The practice of physical activity and adherence to the Mediterranean diet (AMD) have been extensively studied for their relationship with kinanthropometric, body composition and physical fitness variables. However, no previous study has analyzed whether these healthy habits are equally determinant for the differences found in kinanthropometric, body composition and physical fitness variables or, on the contrary, if one of them is more relevant. For this reason, the objectives of the present study were: (1) to analyze the differences in kinanthropometric, body composition, and physical fitness variables between adolescents with different levels of physical activity and AMD, and (2) to determine whether physical activity and/or AMD are predictors of differences in kinanthropometric variables, body composition or physical fitness in adolescents. The sample consisted of 791 adolescents (404 males and 387 females; mean age: 14.39±1.26 year-old) whose physical activity level, AMD, kinanthropometric variables, body composition and physical fitness, were measured. The results showed differences when considering the level of physical activity in kinanthropometric variables, body composition and physical fitness, but not the level of AMD, which was relevant only when it was poor, and the adolescents were inactive. Nevertheless, the AMD did not seem to exert such a determining effect as to produce significant differences on its own. On the other hand, the practice of physical activity did act as a predictor mainly of changes in the fitness variables. Therefore, the main novelty of the present study is the establishment of an order of importance of the healthy habits acquired by adolescents, concluding that the practice of physical activity is more determinant for the differences found in the study variables.

Eight weeks of high-intensity interval vs. sprint interval training effects on overweight and obese adolescents carried out during the cool-down period of physical education classes: randomized controlled trial.

Objective: The aim of this study was to evaluate the effect of sprint interval training (SIT) and [high intensive interval training (HIIT)] carried out during the cool-down period of the physical education classes on body composition, blood pressure variables (BP) and pulse rate (PR), and cardiorespiratory fitness of adolescents who are overweight and obese, and to compare the differences in enjoyment in response to SIT vs. HIIT. Methods: For this randomized controlled trial, forty-five adolescents were recruited from a high school and were randomly placed into three groups. SIT and HIIT trained for 8 weeks, twice a week, for 12 min/session. Experimental group (EG) 3 was the control, and they maintained their regular physical education class schedule. The SIT group performed 6 sets of 60 s of work (90-95%HRmax) / 60 s of rest (50-55%HRmax), and the HIIT group performed 3 sets of 2 min of work (80-85%HRmax) / 2 min of rest (50-55%HRmax). Results: Both experimental groups showed a significant improvement in fat mass (FM) (%) and trunk FM (kg). In addition, EG2 reported a significance improvement in lean mass (kg), blood pressure BP (mmHG), systolic blood pressure (SBP) (mmHg), diastolic blood pressure (DBP) (mmHg), PR (bpm), and VO2max (ml/kg/min). Conclusion: The present study found that a HIIT protocol performed during the cool-down period of the physical education classes generated adaptations such as improvement in body composition, BP variables and PR, and cardiorespiratory fitness, in overweight and obese adolescents. In contrast, the group of overweight and obese adolescents who performed SIT showed limited benefits, with changes in fat mass only.

The Effect of Resistance Training with Outdoor Fitness Equipment on the Body Composition, Physical Fitness, and Physical Health of Middle-Aged and Older Adults: A Randomized Controlled Trial.

This study examined the effect of outdoor-fitness-equipment-based resistance training on the health parameters of middle-aged and older adults, as well as analyzing the effect of age on the results found. A total of 149 volunteers were randomly assigned to the training (TG) and control (CG) groups. The TG performed two weekly sessions of resistance training for 8 weeks using outdoor fitness equipment, while the CG continued with their regular daily activities. Body composition was measured using DXA, and the maximal isometric voluntary contraction in knee extension, elbow flexion, and hand grip were assessed, along with the 4 m walk test, the Timed Up and Go Test, and the Short Form 36 Health Survey Questionnaire. The TG showed a significant increase in the lean mass index (p = 0.002) and maximal isometric voluntary contraction in both legs (p < 0.001) and arms (p < 0.001), as well as in physical functioning (p < 0.001) and the role physical dimension (p = 0.006) of the Short Form 36 Health Survey Questionnaire, compared to the CG, which showed a decrease in all these variables. In addition, the TG showed a greater decrease in fat mass (p < 0.001), fat mass index (p = 0.003), and the Timed Up and Go Test (p < 0.001) than the CG. Age conditioned the evolution of most of the variables analyzed (p < 0.05). In conclusion, resistance training with outdoor fitness equipment may be useful for improving the health of middle-aged and older adults, although age is a factor that could influence the adaptations found.

Adherence to the Mediterranean Diet and Its Influence on Anthropometric and Fitness Variables in High-Level Adolescent Athletes.

The objectives of the present research were to analyze adherence to the Mediterranean diet (AMD), to observe which variables most affect AMD, and to analyze whether AMD affects physical fitness and anthropometric parameters in high-level adolescent athletes. A total of 96 adolescent athletes in the under-16, under-18, and under-20 categories selected by the Athletics Federation of the Region of Murcia, of whom 47 were male (age = 18.31 ± 2.31 years old) and 49 female (age = 17.27 ± 1.44 years old), participated in this study. They completed the KIDMED questionnaire to discover their AMD, as well as an anthropometric and physical condition assessment. Results: The findings show that 61.45% had an excellent degree of AMD, 31.25% a moderate one, and 7.30% a poor one. The parameters that most conditioned AMD were the consumption of fruit, vegetables, nuts, legumes, fish, breakfast cereals, and dairy products (p = 0.011-0.000). AMD did not show significant differences in anthropometric characteristics and physical fitness (p = 0.057-0.996). Conclusions: The majority of high-level adolescent athletes have a moderate or excellent AMD. The degree of AMD seems to have no influence on physical fitness and anthropometric parameters in this population.

Pattern of Consumption of Sports Supplements of Spanish Handball Players: Differences According to Gender and Competitive Level.

(1) Background: Given the physiological characteristics of handball, players may require the use of certain sports supplements (SS). However, very few studies have investigated the consumption of SS in handball. The aims were to determine the number of handball players who consume SS, to analyze their SS consumption pattern according to gender and competitive level, and to assess whether the SS they consume are supported by scientific evidence, and to which group they belong according to the classification of the Australian Institute of Sport (AIS). (2) Methods: A descriptive-correlational study was carried out on the habitual consumption of SS in 360 federated Spanish players by using a self-administered and validated questionnaire. (3) Results: These showed 65.8% of the sample consumed SS. According to the total number of participants, the most consumed supplements were from Group A: sports drinks (30.8%) and whey protein (30.4%). When analyzing the data by gender, the men's consumption was significantly higher for whey protein (p < 0.001), caffeine (p = 0.009), and creatine monohydrate (p < 0.001). When analyzed by competitive level, the provincial category players group showed a significantly lower consumption than the rest of the groups for protein bars (p = 0.038), whey protein (p = 0.005) and creatine monohydrate (p < 0.001), while the honor division group showed a significantly higher intake of creatine monohydrate than the remaining groups (p < 0.001). (4) Conclusions: The handball players showed a moderate consumption of SS, without using substances that were not supported by scientific evidence and opting in most cases for supplements belonging to group A from the AIS classification. Men tended to consume more SS, and SS consumption increased based on competitive level.

Mobile application interventions to increase physical activity and their effect on kinanthropometrics, body composition and fitness variables in adolescent aged 12-16 years old: An umbrella review.

BACKGROUND: The aims of the present umbrella review were (a) to summarize the available evidence on the effectiveness of mobile applications aimed at increasing physical activity; (b) to analyse the effect of an increase in physical activity on kinanthropometric variables, body composition and physical fitness of adolescents aged 12-16 years old; and (c) to determine the strengths and limitations of the interventions carried out with adolescents aged 12-16 years old through the use of mobile applications, to provide recommendations for future research. METHODS: The most relevant inclusion criteria were (a) adolescents aged 12-16 years old; (b) interventions carried out only with mobile apps; (c) pre-post measurements; (d) participants without illnesses or injuries; and (e) interventions lasting more than 8 weeks. The databases used to identify the systematic reviews were the Web of Science, Google Scholar, PubMed and Scopus. Two reviewers independently used the AMSTAR-2 scale to measure the methodological quality of the included reviews and also carried out an analysis of external validity, with a third reviewer participating in the cases in which consensus was not reached. RESULTS: A total of 12 systematic reviews were included (these included a total of 273 articles that used electronic devices, of which 22 studies exclusively used mobile applications with adolescents aged 12-16). Regarding physical activity and its effect on body composition, kinanthropometric variables and physical fitness, no significant differences were found for any of the variables analysed, and the results were not sufficiently consistent to determine the influence of these interventions. CONCLUSIONS: It is important to highlight that the scientific research conducted so far showed that mobile applications were not effective in increasing physical activity and changing the kinanthropometric variables, body composition or physical fitness of adolescents. Thus, future research with stronger methodological rigour and larger samples is needed to provide stronger evidence.

Importance of training volume through the use of step trackers apps promoted from the subject of physical education to change body composition, physical fitness and physical activity in adolescents and the influence of gender✰,✰✰.

The aim of the present study was to determine the changes in physical activity level (PA), kinanthropometric and derived variables, and physical fitness in adolescents, as a result of an out-of-school intervention with mobile step tracker apps promoted from the field of physical education, according to the volume of training completed and gender. A randomized controlled trial was carried out with 400 adolescents (210 males and 190 females) aged 12 to 16 years old (mean age: 13.96 ± 1.21 years-old). Adolescents were divided into experimental group (EG) (n = 240) and control group (CG) (n = 160). Two measurements were carried out, separated by a 10-week intervention, and PA, kinanthropometric variables and physical condition were measured. During the intervention, EG must use Strava (n = 74); Pokémon Go (n = 59); Pacer (n = 60); and MapMyWalk (n = 47) a minimum of 3 times per week, covering an incremental distance from 7,000 steps per day (week 1) to 12,500 steps per day (week 10). After that, EG were divided in quartile according to the volume of training completed. The results obtained showed a significant increase between pre-and post in PA (p = 0.009-0.044) and curl-up (p < 0.001-0.040) in EG regardless the quartile of compliance, and a reduction in fat variables (p < 0.001) and an increase in CMJ in 75-100 % compliance group (p = 0.005). The introduction of the covariate gender did not introduce changes in the intra-group evolution. On inter-group differences, differences were only found for the post-test values between 0-25 % Vs 25-50 % and between 50-75 % Vs 75-100 % with the group that completed a longer distance being the one that showed the lowest values in the post-test in both cases. When including the covariate gender, no significant differences were found for either the pre-test or the post-test on either variable. To conclude, a higher training volume with mobile apps seems to be relevant in the increase PA and strength and decrease of fat mass. The gender factor is not influential in the intra-group changes, but it is influential in the inter-group differences.

Influence of physical fitness components on personality factors and risk perception of children and adolescents: a cross-sectional study.

OBJECTIVES: To examine the associations of cardiorespiratory fitness (VO2 max) and muscular strength with indicators related to the risk scale, such as perceived competence, sensation seeking, competitiveness, risk taking and risk perception in sports. DESIGN: Cross-sectional study. SETTING: High schools from the Region of Murcia (Spain). PARTICIPANTS: Three-hundred-and-seventeen adolescents participated (mean age: 13.69±1.2 years old). PRIMARY AND SECONDARY OUTCOME MEASURES: Body mass, body height, Course-Navette test, upper limb strength and psychoeducational factors that determine the propensity towards sports accidents in school children, the Sports Accident Propensity Scale were evaluated. It was performance t-test for independent samples, stepwise multiple linear regression models and a multiple mediation analysis. RESULTS: The analysis showed significant differences with respect to sex in height, VO2 max, handgrip strength and in all factors of the questionnaire (p=0.02-<0.01). Adolescents who presented greater VO2 max, strength in the handgrip test and age showed a higher score in factors 1 and 3. Higher scores in factor 2 were associated with better VO2 max and strength in handgrip test. Youngers and better values of strength in the handgrip showed higher score in factors 4 and 5. The mediation analysis with two mediating variables (handgrip strength and VO2 max) showed a significant indirect effect. When handgrip strength and VO2 max were included in the equations, the association between sex and each factor ceased to be significant. CONCLUSION: This study highlights the potential benefits of muscular strength (handgrip) and VO2 max in the perceived risk scale, and the variable of age on this. TRIAL REGISTRATION NUMBER: Clinical trial: NCT05544370 (pre-results).

The impact of videogames on the mood of amateur youth players during consecutive games.

Introduction: Esports have experienced tremendous growth in recent years. In the scientific field, previous research has shown the determining role of psychology in competitive performance, but little is known about the factors that may be more determinant. In addition, in the amateur field, where fun and enjoyment are the most important factors, it has been observed that players can see their psychological state altered due to different factors, but it is not known if the outcome of the game (win or lose) can be influential. For this reason, the aim of the present investigation was to analyze changes in players' mood between three consecutive games as a function of the outcome of each game. Methods: A total of 14 amateur players participated in the research, all of them with previous experience and being regular League of Legends players. The participants completed the POMS questionnaire before the start of each game and the outcome of each game was recorded at the end. Results: The results showed that no significant pre-game differences were found in any of the games, regardless of winning or losing. Significant differences were found in the pre-game mood between the first and second game, according to the outcome of the first game, and between the second and third game, according to the outcome of the second game. Between the first and second games, there was a significant increase in depression (p = 0.038) and anger (p = 0.003) when the first game was lost; and between the second and third games, there was a decrease in tension (p = 0.003) and anger (p = 0.022) when the second game was won. In addition, it should be noted that fatigue increased significantly after each game, regardless of the outcome, and with respect to the change in mood, this was more noticeable when the first game was lost and the second was won, as significant changes were observed in tension (p = 0.028), depression (p = 0.030) and anger (p = 0.006). Conclusion: Pre-match mood does not influence post-match performance, but mood changes do occur between successive matches depending on the outcome of the match.

Skinfolds compressibility and digital caliper's time response in skinfold measurement in male and female young adults.

BACKGROUND: The skinfold caliper reading of the skinfold thickness depends on its dynamic compressibility. This has led to the fact that, while it is indicated that skinfold readings should be taken when the reading is stable, there is no consensus on at what second the reading should be taken after the application of the skinfold caliper. The new Lipowise PRO digital skinfold caliper was used to analyze the evolution of skinfold readings under skinfold caliper pressure. The aim of the present investigation were: a) to analyze the evolution of the reading time of individual skinfolds when subjected to skinfold caliper pressure and when the skinfold reading reaches stability; b) to describe the physical behavior of skinfold tissues' time response to skinfold caliper pressure, and to explore differences between sites and subjects' skinfolds compressibility; and c) to analyze the sex differences in both the reading and the evolution of the skinfold over time. METHODS: A descriptive cross-sectional design was followed with a convenience sample of 165 healthy young adults (79 males and 86 females), with eight skinfolds measured using the Lipowise PRO skinfold caliper. The Lipowise PRO skinfold caliper uses a programmable reading time allowing for the measurement of the skinfold's thickness at a rate of 100 times per second, and monitoring skinfold behavior over the 3-second measurement period, thereby enabling the assessment of the tissue response to the constant force exerted by the skinfold caliper jaws. RESULTS: All skinfolds showed statistical differences in terms of compressibility characteristics (p < 0.001). Significant differences were found between measurement time points for individual skinfolds and sum of skinfolds (p < 0.001-0.025). Stabilization being found depending on the skinfold measured from 1.5 seconds for biceps, subscapular, iliac crest, supraspinale, abdominal, and thigh skinfolds; 2.0 seconds for ∑6 and ∑8 skinfolds; and 2.5 seconds for triceps and calf skinfolds. It was observed an effect of sex on this issue (p < 0.001-0.030). More specifically, in the case of males, the supraspinale and abdominal skinfolds stabilized after 1.5 seconds; the calf skinfold and ∑6 and ∑8 skinfolds stabilized after 2 seconds; while the rest of the skinfolds did not stabilize until 3 seconds. In the case of females, no stabilization of the triceps skinfold was found, while the rest of the individual skinfolds and the ∑6 and ∑8 skinfolds stabilized from 1.5 seconds. A regression analysis indicated that skinfold thickness could be predicted based on measurement time in 50-77% of the cases (p = 0.001). CONCLUSION: A skinfold caliper application, using the digital caliper Lipowise PRO, of three seconds may be sufficient for achieving stability in the measurement and for obtaining the minimum value for most individual and sum of skinfolds. However, there are certain skinfolds that may require more time when performed on certain individuals, which vary according to sex.

What Variables Allow the Differentiation between More and Less Successful Adolescent Volleyball Players?

Kinanthropometric and physical fitness variables have been habitually used for the detection of sports talent in adolescent populations. Considering these variables, players who obtained better scores than their peers in kinanthropometric and physical fitness variables have been traditionally selected for promotion in their teams, without taking into account the possible effect of the maturation process. The aim of the present study was to analyse the differences between adolescent volleyball players in terms of success assessment and the age category, as well as to identify variables that may predict success in volleyball. A total of 101 volleyball players in the U14 age category (28 boys and 73 girls; age = 13.28 ± 0.49 years) and 99 players in the U16 age category (20 boys and 79 girls; age = 15.24 ± 0.59 years) participated in the study. Significant differences were observed in biological maturation in male groups (p < 0.001-0.041), kinanthropometric variables related to bone structure and muscle mass in male groups (p < 0.001-0.048), in variables related to adipose tissue in the U16 female group (p = 0.012-0.032) and in physical fitness tests related to muscle strength and power (p < 0.001-0.049), indicating that more successful (MS) players showed a more advanced biological maturation process, higher values of kinanthropometric variables related to bone structure and muscle mass, and lower values in variables related to adipose tissue, as well as higher levels of physical fitness. The difference in biological maturation and its relationship with structural and muscular anthropometric variables in boys, and physical fitness tests related to muscle strength and power in both boys and girls, are of great importance in the selection process of sports talent in volleyball. These findings should be considered by clubs and coaches, who could be discarding players who could improve their sports performance in later stages when their maturational development is equalised.

The Role of Basic Psychological Needs in the Adoption of Healthy Habits by Adolescents.

Previous research in this field has not examined the significance of each of the basic psychological needs (BPNs) on changes in the physical activity level, adherence to the Mediterranean diet (AMD), kinanthropometric and derived variables, and the physical fitness of adolescents. Therefore, the purpose of this study was (a) to examine the variances in physical activity, AMD, and kinanthropometric and derived variables, as well as fitness levels, among adolescents with varying degrees of satisfaction regarding each of the BPNs and (b) to assess the differences in the study variables among adolescents based on whether the BPNs are satisfied individually or jointly. The sample consisted of 791 adolescents (404 males and 387 females; average age: 14.39 ± 1.26 years old). The findings indicated that adolescents in the highest percentiles (75-100) of competence, autonomy, or relatedness showed higher scores in physical activity and AMD and better kinanthropometric and physical fitness variables than adolescents in the lowest percentiles (0-25). Adolescents who showed joint satisfaction of all BPNs showed the best results on all variables analyzed. In addition, it should be noted that competence played the most relevant role.

Influence of Pokémon Go Playing Style on Physical Activity and Its Effect on Kinanthropometry Variables and Body Composition in Adolescents.

BACKGROUND: Pokémon Go is a mobile app that offers both continuous and intermittent (gamified) gameplay, but no previous research in adolescents is known to have addressed changes in physical activity and body composition according to playing style. For this reason, the aims of the present investigation were (1) to establish the differences in the level of physical activity, and its influence on the kinanthropometric and body composition, of the adolescent population, considering their Pokémon Go playing style; and (2) to analyze whether the practice of previous physical activity has an influence on the effects of the use of Pokémon Go on the level of physical activity and changes in kinanthropometric and body composition variables. METHODS: A total of 94 adolescents (50 males and 44 females; mean age: 13.66 [1.17] years-old; mean body mass index: 20.82 [4.03] kg/m2) whose physical activity level and body composition were measured, participated in the investigation. Two groups of adolescents completed a 10-week intervention using Pokémon Go continuously (n = 30) or intermittently (n = 31), while the control group (n = 33) did not use any after-school app. A one-way analysis of variance (ANOVA), a multivariate analysis of variance, and 2 repeated-measures ANOVA were performed to analyze the data. RESULTS: Inactive adolescents in the continuous use group increased their physical activity between the pretest and posttest (P = .038), but this did not occur in the active group. Regarding body composition variables, the increase in body mass (P < .001) and body mass index (P = .006) in the control group was significantly higher than in the continuous use group of adolescents who were inactive, but not in the active group, while the decrease in fat mass (P < .001-.036) and sum of 3 skinfolds (P < .001-.003) was significantly higher in both Pokémon Go use groups as compared to the control group, regardless of the previous physical activity level. CONCLUSIONS: The continuous style of play seems to be more effective in increasing physical activity in adolescents, but the changes in body composition and kinanthropometric variables occur similarly with continuous and intermittent gameplay. Therefore, the playful use of Pokémon Go can be used in educational and health fields to produce changes in body composition in this population.

Effects of a Pilates programme in spinal curvatures and hamstring extensibility in adolescents with thoracic hyperkyphosis: a randomised controlled trial.

AIM: To evaluate the effects of a 9-month Pilates exercise programme on the sagittal spinal posture and hamstring extensibility of adolescents with thoracic hyperkyphosis. DESIGN: Randomised controlled trial with blinded examiner. PATIENTS: One-hundred and three adolescents with thoracic hyperkyphosis. INTERVENTIONS: Participants were randomly placed into an experimental group which participated in a Pilates exercise programme implemented for a total of 38 weeks (two sessions/week, 15 min/session) (Pilates group (PG), sample = 49, or control group (CG), sample = 48). MAIN OUTCOME MEASURES: The outcome measures were the thoracic curve in sagittal spinal curvature in relaxed standing, sagittal spinal curvatures and pelvic tilt in relaxed standing and sit-and-reach positions, and hamstring extensibility. RESULTS: There was a significant adjusted mean difference between groups in favour of the PG in the thoracic curve in relaxed standing position (-5.6°, p = 0.003), pelvic tilt (-2.9°, p = 0.03) and all straight leg tests (p<0.001). The PG showed a significant change in thoracic curve (-5.9, p<0.001) and in lumbar angle (4.0, p = 0.001) in relaxed standing position and in all straight leg raise tests (+6.4 to +15°, p<0.0001). CONCLUSIONS: The adolescents with thoracic hyperkyphosis from the PG had a decreased thoracic kyphosis in relaxed standing position, and improved hamstring extensibility as compared with the CG. More than 50% of the participants obtained kyphosis values inside normality, showing an adjusted mean difference between groups in the thoracic curve of about 73% of the baseline mean, resulting in a large improvement and high clinical importance. TRIAL REGISTRATION NUMBER: NCT03831867.

Influence of Exogenous Factors Related to Nutritional and Hydration Strategies and Environmental Conditions on Fatigue in Endurance Sports: A Systematic Review with Meta-Analysis.

The aim of this systematic review with meta-analysis was to examine the influence of exogenous factors related to nutritional and hydration strategies and environmental conditions, as modulators of fatigue, including factors associated with performance fatigability and perceived fatigability, in endurance tests lasting 45 min to 3 h. A search was carried out using four databases: PubMed, Web of Science, SPORTDiscus, and EBSCO. A total of 5103 articles were screened, with 34 included in the meta-analysis. The review was registered with PROSPERO (CRD42022327203) and adhered to the PRISMA guidelines. The study quality was evaluated according to the PEDro score and assessed using Rosenthal's fail-safe N. Carbohydrate (CHO) intake increased the time to exhaustion (p < 0.001) and decreased the heart rate (HR) during the test (p = 0.018). Carbohydrate with protein intake (CHO + PROT) increased lactate during the test (p = 0.039). With respect to hydration, dehydrated individuals showed a higher rate of perceived exertion (RPE) (p = 0.016) and had a higher body mass loss (p = 0.018). In hot conditions, athletes showed significant increases in RPE (p < 0.001), HR (p < 0.001), and skin temperature (p = 0.002), and a decrease in the temperature gradient (p < 0.001) after the test. No differences were found when athletes were subjected to altitude or cold conditions. In conclusion, the results revealed that exogenous factors, such as nutritional and hydration strategies, as well as environmental conditions, affected fatigue in endurance sports, including factors associated with performance fatigability and perceived fatigability.

The Degree of Problematic Technology Use Negatively Affects Physical Activity Level, Adherence to Mediterranean Diet and Psychological State of Adolescents.

The previous scientific literature has shown how detrimental addictive internet and mobile phone use can be for the adolescent population. However, little is known about their influence on the physical activity, kinanthropometry and body composition, nutrition patterns, psychological state, and physical fitness of this population. For this reason, the objectives of this research were (a) to determine the differences in the physical activity level, kinanthropometric and body composition variables, adherence to Mediterranean diet (AMD), psychological state, and physical fitness according to gender and different levels of problematic use of the internet and mobile phones; and (b) to establish the differences in the physical activity level, kinanthropometric and body composition variables, AMD, psychological state, and physical fitness among adolescents when considering problematic use of the internet and mobile phones in combination. The sample consisted of 791 adolescent males and females between 12 and 16 years of age (1st to 4th course) from four compulsory secondary schools (404 males and 387 females; mean age: 14.39 ± 1.26 years-old; mean height: 163.47 ± 8.94 cm; mean body mass: 57.32 ± 13.35 kg; mean BMI: 21.36 ± 3.96 kg/m2). The physical activity level (baseline score: 2.64 ± 0.67), kinanthropometric variables and body composition, AMD (baseline score: 6.48 ± 2.48), psychological state (baseline life satisfaction: 17.73 ± 4.83; competence: 26.48 ± 7.54; autonomy: 25.37 ± 6.73; relatedness: 24.45 ± 6.54), and physical condition variables were measured. The results showed that adolescent males and females with problematic internet and/or mobile phone use presented a worse psychological state, but it is especially relevant to highlight that females also had a lower level of physical activity and AMD, with problematic mobile phone use being especially relevant, mainly in the psychological state of adolescents. In conclusion, problematic use of the internet and mobile phones can have detrimental effects on the level of physical activity, AMD, and psychological state of adolescents, with the differences found in females being particularly relevant.

Exploring the perception of barriers to a dual career by student-athletes with/out disabilities.

In recent years, there has been an increase in knowledge about the barriers experienced by people with disabilities in the education system or sports. However, no studies have analyzed the barriers for those who try to succeed in both disciplines (dual career). The purpose of this study was to examine the barriers faced by student-athletes with/out disability to a dual career combining studies and sport. Two groups were involved in the study (n = 162): student-athletes with disabilities (n = 79) and student-athletes without disabilities (n = 83). Data collected included: (a) socio-demographic aspects; and (b) barriers towards achieving a good balance between sport and academics during the dual career, through the "Perceptions of dual career student-athletes" (ESTPORT) questionnaire. The results showed that student-athletes with disabilities were more likely to perceive in a greater extent the barriers, the university is far from my home (p = 0.007) and the university is far from my training site (p = 0.006), I find myself unable to balance study and training time (p = 0.030), I have to take care of my family (p<0.001), and my current job does not allow me to study enough (p<0.001). The MANOVA analysis showed that the factors gender, competitive level, and employment status had an influence on the perception of some barriers between groups. In conclusion, student-athletes with disabilities perceived barriers more strongly than those without disabilities, and measures are needed to ensure their inclusion in the education system.

Differences in Psychological Variables and the Performance of Female Futsal Players according to Playing Position, Match Result and Menstruation.

Futsal performance has been extensively investigated in previous studies, demonstrating that the psychological state of the players or the playing position condition performance. However, research with female indoor soccer players is scarce; therefore, menstruation has not been considered as a determinant aspect for performance in females. Previous research has shown the influence of menstruation on the psychological state and performance of players of different sports; however, there is no known research on female futsal players. For this reason, the aims of the present research were to establish the differences in pre-match psychological variables and offensive performance as a function of playing position, match result and menstruation. A total of 132 s division Spanish players participated in the research. All participants completed the Questionnaire of Psychological Needs of the Athlete-15, and their regular league matches were recorded and subsequently analyzed to determine their offensive performance. The results showed differences according to playing position: pivots and closers showed greater motivation than wings, while the pivots showed greater activation and shots on goal than the wings and closers. Regarding match results, pivots demonstrated more shots on goals than closers only when the match was lost. In addition, the motivation and activation of the pivots, as well as the number of shots on goal, were higher than that of the wings and closers only when they were not menstruating.