Influence of Preterm Birth and Low Birthweight on Physical Fitness: A Systematic Review, Meta-Analysis, and Meta-Regression.

BACKGROUND: Preterm birth and low birthweight (LBW) might be associated with reduced physical fitness, although evidence remains inconclusive. OBJECTIVE: To examine the influence of preterm birth and LBW on physical fitness, as well as to assess whether variables such as gestational age, birthweight, or age at assessment moderate these effects. METHODS: PubMed, Scopus, and PsycINFO were systematically searched from inception to 7 December 2023 for case-control and cohort studies analyzing the association between preterm birth or LBW (or gestational age or birthweight as continuous variables) with at least one physical fitness-related outcome (i.e., cardiorespiratory fitness (CRF), muscle strength, flexibility, speed, agility). Random-effects meta-analysis and meta-regression models were used to estimate the pooled effect size, as well as to examine potential associations between the magnitude of the effect and gestational age, birthweight, or age at assessment. RESULTS: Fifty-two studies (n = 920,603 participants, average age ranging from 4.7 to 34.4 years) were included. Preterm birth was associated with reduced CRF (standardized mean difference (SMD) = -0.38, 95% confidence interval (CI) = -0.51 to -0.25) and muscle strength (SMD = -0.44, 95% CI = -0.79 to -0.08). LBW was associated with reduced CRF (SMD = -0.40, 95% CI = -0.64 to -0.17), muscle strength (SMD = -0.18, 95% CI = -0.24 to -0.13), flexibility (SMD = -0.11, 95% CI = -0.22 to -0.01), and agility (SMD = -0.99, 95% CI = -1.91 to -0.07). Meta-regression analyses showed that a lower gestational age or birthweight were associated with larger reductions in physical fitness, whereas no consistent association was found for the age at assessment. CONCLUSION: Both preterm birth and LBW seem associated with reduced physical fitness regardless of age, with larger reductions overall observed in individuals with lower gestational age or birthweight. These findings might support the implementation of preventive strategies (e.g., fitness monitoring and physical exercise interventions) in these populations through the life course. PROSPERO registration: CRD42021231845.

Physical Activity and Cognitive Performance in Early Childhood: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Growing evidence suggests that physical activity (PA) could improve cognitive performance in youths, but whether these effects occur from early childhood remains unclear. OBJECTIVE: To summarize evidence on the effects of PA interventions on cognitive performance in early childhood. METHODS: We performed a systematic search in PubMed, Scopus, Web of Science and PsycINFO (from inception to 6 September 2023) for randomized controlled trials assessing the effects of PA interventions (≥ 3 weeks) on cognitive-related outcomes in early childhood (3-6 years). We conducted a random-effects meta-analysis when five or more studies assessed a given outcome. The potential moderating role of participant (e.g., age) and intervention characteristics (e.g., duration, volume, intensity, cognitive engagement) was also assessed. RESULTS: We found a total of 24 studies (N = 3483 children) that were deemed to be of overall fair methodological quality. PA interventions were supervised and lasted between 3 and 24 weeks. The most common session duration was 30 min, with a frequency of two sessions per week. Pooled analyses revealed that PA interventions have positive effects on all analysed outcomes, including attention (standardized mean difference (SMD) = 0.49, 95% confidence interval (CI) 0.18-0.79, p = 0.002), inhibition (SMD = 0.45, 95% CI 0.06-0.84, p = 0.022), working memory (SMD = 0.50, 95% CI 0.18-0.82, p = 0.002), cognitive flexibility (SMD = 0.39, 0.15-0.62, p = 0.002) and vocabulary (SMD = 1.18, 0.19-2.16, p = 0.019). Sensitivity analyses confirmed the benefits in all cases except for inhibition (p = 0.062). No consistent differences were found relating to any moderator variable. CONCLUSIONS: Although further research is warranted, our findings suggest that PA interventions may improve cognitive performance in early childhood, particularly in the domains of attention, inhibition, working memory, cognitive flexibility and vocabulary. These findings might support the implementation of PA interventions from early childhood. PROSPERO REGISTRATION: CRD42021249319.

The role of supervision and motivation during exercise on physical and mental health in older adults: a study protocol for a randomized controlled trial (PRO-Training project).

BACKGROUND: Although supervised exercise is frequently recommended for older adults, its superiority over unsupervised exercise remains uncertain. Furthermore, whether motivational techniques could help to enhance the effectiveness of the latter remains to be elucidated. The present randomized controlled trial aims to determine the role of supervision and motivational strategies on the safety, adherence, efficacy, and cost-effectiveness of different exercise programs for improving physical and mental health in older adults. METHODS: Participants (n = 120, aged 60-75 years) will be randomly allocated into five groups: 1-Control (CON), 2-Supervised exercise without motivational intervention (SUP), 3- Supervised exercise with motivational intervention (SUP +), 4- Unsupervised exercise without motivational intervention (UNSUP) and 5- Unsupervised exercise with motivational intervention (UNSUP +). Over 24 weeks, all exercise groups will participate in a multicomponent exercise program three times/week (performed in group classes at a center for SUP and SUP + , or home without supervision but with the help of a mobile app for UNSUP and UNSUP +), while the CON group will maintain their usual lifestyle. The motivational intervention (for SUP + and UNSUP + groups) will be based on the self-determination theory, including strategies such as phone calls, interactive workshops, motivational messages, informative infographics and videos. Primary outcomes will include safety, adherence, costs, and lower-body muscular function using a leg press machine. Secondary outcomes will include upper-body muscular function, physical and cardiorespiratory function, blood pressure and heart rate, body composition, health-related quality of life, cognitive performance, anxiety, depression, physical activity levels, sleep and sedentarism, biochemical markers, motivators and barriers to exercise. Assessments will be conducted at baseline, mid-intervention (i.e., week 13), at the end of the intervention (i.e., week 25), and 24 weeks later (i.e., week 49). DISCUSSION: The findings of this trial might provide valuable insights into the role of supervision and motivational strategies on the effectiveness of exercise programs for older adults. Additionally, the study could contribute to developing cost-effective interventions, supporting the design of future public policies for healthy aging. TRIAL REGISTRATION: NCT05619250. Registered 16 November 2022.

Acute effect of physical activity on academic outcomes in school-aged youth: A systematic review and multivariate meta-analysis.

BACKGROUND: There has been an increase in the number of studies examining the effect of acute and chronic physical activity on academic outcomes in children and adolescents in the last two decades. We aimed to systematically determine the acute effects of physical activity on academic outcomes in school-aged youth and to examine possible moderators. METHODS: We conducted a systematic search using PubMed, Web of Science, SPORTDiscus, and PsycINFO databases (from inception to 11th January 2023) for studies assessing the acute effects of physical activity on academic performance-related outcomes in school-aged youth. A univariate and multivariate meta-analysis was conducted based on a random-effects model with restricted maximum likelihood used to pool the academic outcomes results (Hedge's g). RESULTS: We included 11 articles (803 children and adolescents [range: 6-16 years]) in the systematic review. Overall, acute physical activity increased academic outcomes (Hedge's g = 0.35, 95% CI: 0.20-0.50). Multivariate meta-analyses revealed that physical activity increased academic performance in mathematics (Hedge's g = 0.29, 95% CI: 0.16-0.42) and language (Hedge's g = 0.28, 95% CI: 0.09-0.47). Only behavior change techniques (Hedge's g = 0.54, 95% CI, 0.18-0.90, p < 0.001) played a significant role in this relationship. CONCLUSIONS: A single bout of physical activity can improve academic outcomes in school-aged youth, which may serve as a complementary tool for the educational field. However, the observed heterogeneity in the results indicates that we should interpret the findings obtained with caution.

Influence of preterm birth on physical fitness in early childhood.

Evidence suggests that preterm birth is associated with an impaired physical fitness later in life, but whether these effects are already visible since early childhood remains unknown. We aimed to compare the physical fitness of preterm preschoolers with that of children born at term. Children aged three to six years and born preterm (<35 weeks) were recruited from a Neonatal Intensive Care Unit, and children born at term (>37 weeks) were included as controls. A variety of physical fitness indicators (strength, cardiorespiratory fitness, agility, flexibility and balance) were assessed with the PREFIT battery and the adapted sit and reach test. Physical activity levels were measured through the PrePAQ questionnaire. A total of 98 preterm children (gestational age 32.4 ± 2.3 weeks, age 5.1 ± 0.8 years) and 74 controls (gestational age 39.9 ± 1.0 weeks, age 4.8 ± 0.9 years) were analysed. Despite no significant differences in physical activity levels (p > 0.05), preterm children showed an overall poorer physical fitness compared to controls. Specifically, preterm children had an impaired handgrip strength (-13.95%, p < 0.001), lower-limb muscle strength (-12.67%, p = 0.003), agility (-14.9%, p = 0.001), cardiorespiratory fitness (-12.73% p = 0.005) and flexibility (-17.04%, p = 0.001) compared to controls. An inverse dose-response association was observed between the level of prematurity and physical fitness, with very preterm children (gestational age ≤32 weeks) presenting the poorest fitness levels. In summary, prematurity seems to impair physical fitness since early childhood, which might support the need for promoting preventive strategies (e.g. fitness monitoring and applying exercise interventions).Highlights Preterm children present an impaired physical fitness compared with peers born at term since early childhood (3-6 years), as reflected by lower muscle strength, agility, flexibility and cardiorespiratory fitness.A greater impairment of physical fitness in observed in children born very preterm (≤32 weeks of gestation).These findings might support the implementation of preventive strategies (e.g. fitness monitoring and exercise training) in preterm children since early childhood.

School-based physical activity interventions and language skills: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: School-based physical activity (PA) interventions have proven beneficial for improving cognitive performance and overall academic achievement, but their benefits on language skills remain unclear. We aimed to assess the effects of school-based PA interventions on language skills in children and adolescents. DESIGN: Systematic review with meta-analysis. METHODS: A systematic search was performed in PubMed, PsycINFO and Scopus until September 10th, 2022. We included randomized controlled trials (RCTs) that performed a school-based PA intervention in children/adolescents and that assessed language-related outcomes (i.e., reading, spelling, vocabulary, verbal fluency, comprehension and grammar) or language school grades. Random effect meta-analyses were conducted to pool study results. RESULTS: Thirty-one studies (18,651 participants) were finally included. Significant benefits were observed for reading (standardized mean difference [SMD]: 0.15; 95% confidence interval [CI]: 0.08, 0.22), vocabulary (SMD: 0.71; 95%CI: 0.44, 0.97), and comprehension (SMD: 0.24; 95%CI: 0.09, 0.40), with a non-significant trend (p = 0.083) also observed for language school grades (SMD: 0.40; 95%CI: -0.05, 0.86). No significant benefits were observed for spelling or verbal fluency (both p > 0.05), and no meta-analysis could be performed for grammar skills. No consistent differences were observed between integrated (i.e., performing PA along with the academic content) and non-integrated PA interventions (e.g., extra physical education lessons). CONCLUSIONS: School-based PA interventions appear as an effective strategy for improving different language-related skills, although further research is needed to determine how interventions' and participants' characteristics moderate these effects.

Sport Participation and Academic Performance in Young Elite Athletes.

Strong evidence supports physical activity and fitness levels being positively associated with cognitive performance and overall academic performance in youth. This also applies to sports participation. However, whether participation in sports at the elite level is associated with greater academic performance remains unknown. Thus, the present study aimed to compare the academic performance of young elite athletes to that of control students, as well as to analyze whether the type of sport mediates these results. Between 2010 and 2019, all students from the last Baccalaureate course of the Spanish Elite Sport High School-which also includes non-elite athletes and recreational athlete students, who were categorized as controls-participated in this study. Academic performance was assessed through both the grade point average of the two last Baccalaureate courses and through the average grades from the University Entrance Examinations. Athletes were categorized attending to different sport classifications. A total of 1126 adolescents (570 girls, 18.2 ± 0.6 years) participated in the study, of which 483 and 643 were categorized as elite athletes and control students, respectively. Elite athletes attained a lower overall academic performance than controls (p < 0.001), which was confirmed for both sexes (p < 0.001). These differences were separately confirmed for most academic subjects (p < 0.05), as well as when attending to different sport classifications (all p > 0.05). Young elite athletes attained a lower academic performance than their non-elite peers, regardless of their type of sport. These findings highlight the importance of programs aimed at facilitating dual careers among young elite athletes.

Spatio-temporal brain dynamics of self-identity: an EEG source analysis of the current and past self.

Current research on self-identity suggests that the self is settled in a unique mental representation updated across the lifespan in autobiographical memory. Spatio-temporal brain dynamics of these cognitive processes are poorly understood. ERP studies revealed early (N170-N250) and late (P3-LPC) waveforms modulations tracking the temporal processing of global face configuration, familiarity processes, and access to autobiographical contents. Neuroimaging studies revealed that such processes encompass face-specific regions of the occipitotemporal cortex, and medial cortical regions tracing the self-identity into autobiographical memory across the life span. The present study combined both approaches, analyzing brain source power using a data-driven, beamforming approach. Face recognition was used in two separate tasks: identity (self, close friend and unknown) and life stages (childhood, adolescence, adulthood) recognition. The main areas observed were specific-face areas (fusiform area), autobiographical memory areas (medial prefrontal cortex, parahippocampus, posterior cingulate cortex/precuneus), along with executive areas (dorsolateral prefrontal and anterior temporal cortices). The cluster-permutation test yielded no significant early effects (150-200 ms). However, during the 250-300 ms time window, the precuneus and the fusiform cortices exhibited larger activation to familiar compared to unknown faces, regardless of life stages. Subsequently (300-600 ms), the medial prefrontal cortex discriminates between self-identity vs. close-familiar and unknown. Moreover, significant effects were found in the cluster-permutation test specifically on self-identity discriminating between adulthood from adolescence and childhood. These findings suggest that recognizing self-identity from other facial identities (diachronic self) comprises the temporal coordination of anterior and posterior areas. While mPFC maintained an updated representation of self-identity (diachronic self) based on actual rewarding value, the dlPFC, FG, MTG, paraHC, PCC was sensitive to different life stages of self-identity (synchronic self) during the access to autobiographical memory.

Individual responsiveness to a school-based karate intervention: An ancillary analysis of a randomized controlled trial.

INTRODUCTION: School-based sport interventions have shown beneficial effects on psychosocial functioning and academic performance in children. However, the inter-individual variability in response to these types of interventions remains unclear. We aimed to determine which children benefit most from a school-based sport intervention. METHODS: This is an ancillary analysis of a randomized controlled trial assessing the effects of a 1-year school-based karate intervention (versus "traditional" physical education lessons) in children (7-8 years) from twenty schools across five European countries. Outcomes included psychosocial functioning (Strengths and Difficulties Questionnaire [SDQ] for parents) and academic performance (grade point average). Only participants of the intervention group were included in the present ancillary analysis, and were categorized as responders or non-responders for the analyzed outcomes attending to whether improvements surpassed a minimal clinically important difference. RESULTS: About 388 children (187 girls) from the intervention group completed the study, of which 17% and 46% were considered responders for SDQ and academic performance, respectively. Responders for the SDQ presented higher SDQ scores (i.e., higher psychosocial difficulties) at baseline than non-responders (p < 0.001). Responders for academic performance were mostly males (p = 0.017), with an older age (p = 0.030), and with worse academic performance (p < 0.001) at baseline compared with non-responders, and tended to present higher SDQ scores (p = 0.055). Responders for one outcome obtained greater benefits from the intervention on the other outcome (e.g., responders for SDQ improved academic performance [p < 0.001] compared with non-responders). CONCLUSIONS: A school-based sport intervention (karate) seems particularly effective for children with psychosocial difficulties and low academic performance.

Academic performance and psychosocial functioning in European schoolchildren: The role of cardiorespiratory fitness and weight status.

BACKGROUND: Whether a high cardiorespiratory fitness (CRF) can attenuate the potential detrimental effect of childhood obesity on academic performance and particularly psychosocial functioning remains unclear. OBJECTIVES: To analyse the academic performance/psychosocial functioning of schoolchildren attending to their CRF and weight status. METHODS: 470 schoolchildren (46% girls, 7 ± 0 years) from 20 schools in five European countries were categorized as (i) having overweight/obesity (n = 113) or normal weight (n = 357) attending to body mass index and (ii) 'fit' (n = 282) or 'unfit' (n = 188) based on 20-meter shuttle-run performance (CRF ≥ or <42 ml·kg-1 ·min-1 [boys] and 35 ml·kg-1 ·min-1 [girls], respectively). Academic performance and psychosocial functioning were assessed using the grades attained in school subjects and the Strengths and Difficulties Questionnaire (SDQ) for parents, respectively. RESULTS: Independent of their weight status, fit children showed a greater academic performance and psychosocial functioning than their peers who were unfit and overweight/obese. In fit children, academic performance and psychosocial functioning did not differ between the two weight status categories (normal weight or overweight/obesity). CONCLUSIONS: Children with a higher CRF show a greater performance achievement and psychosocial functioning regardless of their weight status, thereby supporting the 'fat but fit' paradox and reinforcing the importance of improving CRF in this population.

Effects of a school-based karate intervention on academic achievement, psychosocial functioning, and physical fitness: A multi-country cluster randomized controlled trial.

PURPOSE: To examine the effects of a school-based karate intervention on academic achievement, psychosocial functioning, and physical fitness in children aged 7-8 years. METHODS: Twenty schools in 5 different European countries (2 second-grade classrooms per school) participated in a cluster randomized controlled trial (Sport at School trial). Participants were assigned to either a control group, which continued with their habitual physical education lessons, or to an intervention group, which replaced these lessons with a 1-year karate intervention (Karate Mind and Movement program). A total of 721 children (344 girls and 377 boys, 7.4 ± 0.5 years old, mean ± SD) completed the study, of which 333 and 388 were assigned to the control group and intervention group, respectively. Outcomes included academic performance (average grade), psychosocial functioning (Strengths and Difficulties Questionnaire for parents), and different markers of physical fitness (cardiorespiratory fitness, balance, and flexibility). RESULTS: The intervention provided small but significant benefits compared to the control group for academic achievement (d = 0.16; p = 0.003), conduct problems (d = -0.28; p = 0.003), cardiorespiratory fitness (d = 0.36; p < 0.001), and balance (d = 0.24; p = 0.015). There was a trend towards significant benefits for flexibility (d = 0.24; p = 0.056). No significant benefits were observed for other variables, including psychosocial difficulties, emotional symptoms, hyperactivity/inattention, peer problems, or prosocial behaviour (all p > 0.05). CONCLUSION: A 1-year school-based karate intervention was effective in improving academic achievement, conduct problems, and physical fitness in primary school children. The results support the inclusion of karate during physical education lessons.

Anthropometric and fitness normative values for young karatekas.

To provide information regarding the anthropometric and fitness profile of young karatekas and to study its evolution with age. Data from top-level karatekas were included in the analysis: 97 athletes in the U14 category (12-13 years old), 238 in cadet (14-15 years old), 261 in junior (16-17 years old) and 177 in U21 (18-20 years old), which makes a total of 773 athlete data sets. Karatekas underwent anthropometric (weight, height, body mass index and body fat percentage) and fitness (sit and reach, 20-m shuttle run, standing long jump, overhead 3-kg ball throw, 10x5-m shuttle run, and plate-tapping) assessments during the training camps organized by the Spanish National Karate Federation between 1999 and 2016. Male karatekas were taller and heavier, and performed better than females in all the fitness dimensions assessed, except for flexibility and speed of upper limb movements. The obtained cardiovascular and lower-body muscular values indicated that karatekas in this study were placed between the 80th and the 90th percentile when compared with the general population. The results of the agility, coordination and speed of upper limb movements, and flexibility tests showed that the karatekas obtained much higher scores than those observed in age-matched populations. Young karatekas show a high fitness level in comparison with the general population, especially with regards to aerobic performance, lower-body muscular power and upper-limb movement speed. Reference values of anthropometric and fitness dimensions are provided in order to be used by coaches, conditioning trainers and sport scientists when testing young male and female karatekas.

Effects of Videogaming on the Physical, Mental Health, and Cognitive Function of People with Intellectual Disability: A Systematic Review of Randomized Controlled Trials.

Videogames have been applied to improve health-related outcomes in people with intellectual disabilities (ID). For this purpose, it seems necessary to make available the best scientific information concerning the feasibility and potential benefits of playing videogames within this population. This study aimed to systematically review the existing scientific evidence regarding the effects of videogaming on the physical and mental health of people with ID. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a literature search was performed using MEDLINE/PubMed, PEDro, SPORTDiscus, and Scopus up to June 2020. The Physiotherapy Evidence Database (PEDro) scale was used to rate the methodological quality of the included investigations. A total of 17 randomized controlled trials (RCTs) were selected. Data synthesis examined physical health, including anthropometrics, physical fitness, and motor skills, and mental health and cognitive function. Intervention protocols were based on videogames of different nature (i.e., exergames and computerized cognitive training) and showed substantial heterogeneity in duration. Session length varied from 15 to 60 minutes. Five studies achieved a high intervention adherence rate, whereas a low drop-out rate was reported in eight RCTs. Videogaming is a useful therapy for improving physical and cognitive function in people with ID. Exergaming seems to be an interesting physical intervention for increasing fitness and motor skill levels, while sedentary videogaming has shown potential for stimulating cognitive function. Further research to analyze its feasibility and its impact on body composition and mental health is needed.

Severe knee injuries among karate athletes ranking towards the Tokyo Olympic Games: a retrospective study.

BACKGROUND: Injury prevention strategies should be built upon data about the more frequent injuries in each specific sport. Therefore, this study aimed to describe the lifetime prevalence and characteristics of severe knee injuries among world-class karatekas. METHODS: A retrospective study based on a face-to-face survey was conducted. Participants were athletes who competed in World Karate Senior Championships in Madrid 2018, which was a tournament with the highest value to rank athletes to the Tokyo Olympic Games. A questionnaire was used to collect retrospective information on the prevalence and characteristics of severe knee injuries that occurred along elite karatekas sport careers. Odds Ratio (OR) were calculated to identify the association of sex and karate modality (kata / kumite) with severe knee injury risk. RESULTS: Out of the 293 athletes surveyed (23.4±4.0 years; 137 female), 71 (24.2%) had suffered a serious knee injury at some point of their careers, without a statistically significant difference between male and female athletes. There was no difference between the percentage of injuries that took place during training (54.9%) or during competition (45.1%) both in male and female athletes. Kumite athletes suffered more knee injuries during competition than training. The most common injury mechanism for both genders was a pivoting or dodging movement (36.4% in males and 39.5% in females). CONCLUSIONS: The information presented in this study about the prevalence and characteristics (mechanism, anatomical location, moment, time off) of the severe knee injuries in elite karatekas could be useful to design prevention programs to be implemented among karate athletes.

Effects of a school-based karate intervention on academic achievement, psychosocial functioning, and physical fitness: A multi-country cluster randomized controlled trial.

PURPOSE: To examine the effects of a school-based karate intervention on academic achievement, psychosocial functioning, and physical fitness in children aged 7-8 years. METHODS: Twenty schools in 5 different European countries (2 second-grade classrooms per school) participated in a cluster randomized controlled trial (Sport at School trial). Participants were assigned to either a control group, which continued with their habitual physical education lessons, or to an intervention group, which replaced these lessons with a 1-year karate intervention (Karate Mind and Movement program). A total of 721 children (344 girls and 377 boys, 7.4 ± 0.5 years old, mean ± standard deviation) completed the study, of which 333 and 388 were assigned to the control group and intervention group, respectively. Outcomes included academic performance (average grade), psychosocial functioning (Strengths and Difficulties Questionnaire for parents), and different markers of physical fitness (cardiorespiratory fitness, balance, and flexibility). RESULTS: The intervention provided small but significant benefits compared to the control group for academic achievement (d = 0.16; p = 0.003), conduct problems (d = -0.28; p = 0.003), cardiorespiratory fitness (d = 0.36; p < 0.001), and balance (d = 0.24; p = 0.015). There was a trend towards significant benefits for flexibility (d = 0.24; p = 0.056). No significant benefits were observed for other variables, including psychosocial difficulties, emotional symptoms, hyperactivity/inattention, peer problems, or prosocial behavior (all p > 0.05). CONCLUSION: A 1-year school-based karate intervention was effective in improving academic achievement, conduct problems, and physical fitness in primary school children. The results support the inclusion of karate during physical education lessons.

The "Fat but Fit" paradox in the academic context: relationship between physical fitness and weight status with adolescents' academic achievement.

The present study aimed to analyze the relationship between obesity and different physical fitness markers with academic achievement in adolescents, as well as to check if the "Fat but Fit paradox" is applicable in this context. A total of 188 participants (83 boys) ranging from 12 to 18 years (14.51 ± 1.29 years) underwent a series of fitness tests, and were categorized as "fit" or "unfit" attending to their estimated cardiorespiratory fitness (above or below 42 and 35 ml·kg-1·min-1 for boys and girls, respectively). Participants were also categorized according to their body mass index as having overweight/obesity or not. A variety of fitness markers (i.e., cardiorespiratory fitness, lower-body power, sprint time, and flexibility) were positively associated with academic achievement (all p < 0.05), but no associations were found for upper-body power, upper-limb coordination or agility. Both being fit (ß = 0.652, 95% confidence interval: 0.001-1.302) and normoweight (ß = 1.085, 0.171-1.999) were positively associated with academic achievement. A higher academic achievement (p = 0.021) was found for fit and normoweight individuals compared to unfit and overweight/obese ones, but no differences were found for the remaining subgroups. These findings suggest that an optimal physical fitness might attenuate the negative consequences induced by obesity on academic achievement.

Physical activity, dietary habits and sleep quality before and during COVID-19 lockdown: A longitudinal study.

The COVID-19 pandemic has forced the health public authorities to impose a lockdown as an epidemiological containment strategy. This study aimed to provide information regarding the impact of the mandatory confinement on the physical activity, eating disorders risk, sleep quality and well-being on a Spanish sample. An online survey that included the Minnesota Leisure Time Physical Activity Questionnaire, the Eating Attitude Test-26, and Pittsburgh Sleep Quality Index was administered two days after the state of alarm was stablished in Spain and five days after such measures began to be eased. Out of the 693 people who answered the first questionnaire, 161 completed the second one. These participants spent a total of 48 days locked at home, a period during which a significant worsening in all the variables assessed except for the risk of developing eating disorders, was observed: weight (kg), 67.3 ± 14.8 vs 67.7 ± 15.1, p = 0.012; physical activity (MET minutes per week), 8515.7 ± 10260.0 vs 5053.5 ± 5502.0, p < 0.001; sleep problems (total score), 6.2 ± 3.5 vs 7.2 ± 3.9, p < 0.001; self-perceived well-being (score), 4 (3-4) vs 3 (3-4), p < 0.001. The confinement had a significant differential effect on physically active participants, who experienced a significant decline (p < 0.05) on their physical activity levels, quality of sleep and well-being; whereas physically inactive participants did not experience significant changes. Findings from this longitudinal study indicate that a lockdown period due to COVID-19 had a negative impact on the physical activity levels, sleep quality and well-being in a group of physically active Spanish adults. Public health authorities should be aware that people who usually lead an active lifestyle, might be particularly susceptible to such disruptions.

Am I the same person across my life span? An event-related brain potentials study of the temporal perspective in self-identity.

While self-identity recognition has been largely explored, less is known on how self-identity changes as a function of time. The present work aims to explore the influence of the temporal perspective on self-identity by studying event-related brain potentials (ERP) associated with face processing. To this purpose, participants had to perform a recognition task in two blocks with different task demands: (i) identity recognition (self, close-friend, unknown), and (ii) life stage recognition (adulthood -current-, adolescence, and childhood). The results showed that the N170 component was sensitive to changes in the global face configuration when comparing adulthood with other life stages. The N250 was the earliest neural marker discriminating self from other identities and may be related to a preferential deployment of attentional resources to recognize own face. The P3 was a robust index of self-specificity, reflecting stimulus categorization and presumably adding an emotional value. The results of interest emerged for the subsequent late positive complex (LPC). The larger amplitude for the LPC to the self-face was probably associated with further personal significance. The LPC, therefore, was able to distinguish the continuity of the self over time (i.e., between current self and past selves). Likewise, this component also could discriminate, at each life stage, the self-identity from other identities (e.g., between past self and past close-friend). This would confirm a remarkable role of the LPC reflecting higher self-relevance processes. Taken together, the neural representation of oneself (i.e., "I am myself") seems to be stable and also updated across time.

Does Physical Fitness Predict Future Karate Success? A Study in Young Female Karatekas.

OBJECTIVE: To assess the discriminative ability of several fitness dimensions and anthropometric attributes for forecasting competitive success in female karate athletes. METHODS: Fitness and anthropometric data from 98 female junior karatekas obtained during the training camps of the Spanish National Karate Federation between 1999 and 2012 were used. Binary logistic-regression models were built to ascertain whether the set of fitness and anthropometric variables could predict future sporting-performance levels. For this purpose, participants were classified as elite (medalist in World or European Championships in the senior category) or subelite (at least a medalist in Spanish National Championships in cadet or junior but not included in the elite group), according to the results achieved up to 2019. RESULTS: Participants who were subsequently classified as elite karatekas showed significant differences in agility, upper- and lower-body muscle power, and general fitness in comparison with those who were classified as subelite in the senior category. A total of 57 junior female karatekas who were subsequently classified as elite (7) or subelite (50) were included in the binary logistic-regression analysis. Resultant models showed significant capacity to predict karate performance. CONCLUSIONS: Assessing physical fitness in junior categories can be a useful resource to determine future karate success. Coaches in this sport should pay special attention to the levels of muscle power and agility shown by their athletes, as both fitness dimensions could be indicators of future sportive success.

Influence of the Box Dimensions on the Reliability and Validity of the Sit and Reach in Preschoolers.

Ayán Pérez, C, Martínez de Quel, Ó, Álvarez Pérez, S, and González Baamonde, S. Influence of the box dimensions on the reliability and validity of the sit and reach in preschoolers. J Strength Cond Res 34(9): 2683-2692, 2020-This study aimed at analyzing the reliability and validity of the sit and reach (SR) test, when it was performed with a standard SR (SSR) or an adapted SR (ASR) box in preschoolers. To accomplish this, both tests were administered 3 times (familiarization, test, and retest) to a group of 148 children (mean age, 4.99 ± 0.94 years; 49.3% girls), with a week interval between each assessment. The obtained results in each test were compared with those obtained in the passive straight leg raise (PSLR) test with the aim of identifying their construct validity. The internal consistency was found to be between good and excellent for the SSR (α: 0.83-0.92) and excellent for the ASR (α: 0.92-0.96). The SSR showed a good and a fair reliability (intraclass correlation coefficient [ICC], 0.71-0.86), whereas the ASR showed an excellent reliability (ICC, 0.90-0.94) except for the 3-year-old children group (ICC, 0.84). Absolute reliability was excellent for the ASR, whereas the SSR yielded higher SEM and minimum detectable change percentage values. Regarding the criterion-related validity, statistically significant fair correlations were observed between both SR tests and the PSLR test. The ASR yielded higher levels of statistical significance as well as greater correlation coefficients than the SSR. This finding indicates that when it comes to assess flexibility through a low cost and easy-to-implement lineal test in preschoolers, it is advisable to use the SR with a box of reduced dimensions.