Correlates of Sleep Duration in Early Childhood: A Systematic Review.

OBJECTIVE: This systematic review aimed to summarize correlates of sleep duration in children under 5 years of age. METHODS: Six electronic databases (PubMed, PsycINFO, MEDLINE, CINAHL, SPORTDiscus, and Scopus) were searched from inception to May 2019. Observational studies and intervention studies reporting cross-sectional results from baseline data were considered. Data were extracted using a predesigned form and potential correlates were categorized following a sociological framework. RESULTS: One-hundred and sixteen studies, representing 329,166 children, met the inclusion criteria, with a high risk of bias in 62 included studies. A total of 83 correlates of sleep duration were identified. Among the associations studied four or more times, correlates of nap duration were child's age and nighttime sleep onset/bedtime; correlates of nighttime sleep duration were household income, parent marital status, parental adiposity level, nighttime sleep duration at younger age, nighttime sleep onset/bedtime, nighttime sleep wakeup time, and frequency of current bedtime routine; correlate of total sleep duration was screen time. CONCLUSIONS: Young children from low-income households, single families, or having overweight parents may be at risk for short sleep duration. Promoting healthy sleep duration from an early age appears essential. Effective practices may include encouraging an earlier bedtime, limiting screen time, and establishing a regular bedtime routine. The absence of consistent evidence in the psychological, cognitive, and emotional domain as well as the physical environmental domain warrants further research.

Sedentary time and blood pressure in Australian toddlers: The get-up study longitudinal results.

Epidemiological data suggests that the genesis of cardiovascular disease occurs during childhood. Sedentary time (ST) is a main driver of high blood pressure (BP) in adolescents and adults. However, associations between ST and cardiovascular health in young children are uncertain. Prospective associations between ST and BP were assessed among 172 toddlers (88 boys), aged 19.5 ± 3.9 months at baseline, recruited from the GET-UP! Study, Australia and followed over a 12-month period. BP was measured with a digital monitor and z-scores were computed by age and sex for systolic and diastolic BP. Total ST was measured over 7 days using Actigraph accelerometers and expressed over a 24-h period. Multilevel linear regression models were used to assess regression coefficients and standard errors, predicting BP at follow-up from ST at baseline. Analyses controlled for socio-economic status, height, age, gender, group (intervention or control) and zWC at baseline. Adjusted analyses showed that total ST did not predict systolic or diastolic BP (ß = 0.0009, p = 0.368 and ß = 0.002, p = 0.05, respectively). Most likely, longer follow-up periods might be needed to confirm or rule out our results, as the effects of cumulative ST over time on BP values are prone to manifest later in life and track into adolescence and adulthood.

Systematic review on retinal microvasculature, physical activity, sedentary behaviour and adiposity in children and adolescents.

AIM: As retinal microvasculature (RMV) can be assessed non-invasively, it presents an opportunity to examine the health and disease of the human microcirculation, as RMV alterations have been recognised as one of the earliest signs of cardiovascular risk. This review summarises current literature on the associations between physical activity (PA), sedentary behaviour (SB) and/or adiposity and RMV in children and adolescents aged 0-18 years. METHODS: Six databases were searched (MEDLINE, Scopus, Web of Science, ScienceDirect, PsycINFO and CINAHL), through to December 11, 2019. English, Portuguese, French, Spanish or Dutch were the languages searched. Meta-analyses were performed using the meta-analyst software. RESULTS: A total of 6796 studies were screened, and 26 studies were included, representing 24 448 participants, from 12 different countries. Studies reporting results on weight status were twenty-three, PA was assessed in six studies, and SB was assessed in three studies. Four studies examined weight status and PA/SB. Meta-analysis was performed for two studies and showed that children with obesity have smaller retinal arterioles (-2.38 µm difference, 95% CI 0.62, 4.15 µm) and larger retinal venules (2.74 µm difference, 95% CI -4.78, -0.72 µm) than children without obesity. CONCLUSION: Results showed that adiposity was associated with microvascular alterations in children and adolescents. Increased adiposity, lack of PA and high levels of SB were negatively correlated with vessel width parameters.

Association between breaks in sitting time and adiposity in Australian toddlers: Results from the GET-UP! study.

BACKGROUND: In youth, research on the health benefits of breaking up sitting time is inconsistent. Our aim was to explore the association between the number of breaks in sitting time and adiposity in Australian toddlers. METHODS: This study comprised 266 toddlers (52% boys), aged 19.6 ± 4.2 months from the GET-UP! Study, Australia. Body mass index (BMI) was calculated and z-scores by age and sex were computed for waist circumference (WC). Participants were classified as overweight according to the WHO criteria for BMI. For WC, participants with a z-score≥1SD were considered overweight. Sitting time was assessed with activPALs during childcare hours and participants were classified by tertiles of the number of breaks/h in sitting time: <26 breaks/h; 26-39 breaks/h, and >39 breaks/h. Logistic regression assessed odds ratios for non-overweight (BMI or waist circumference categories) by number of breaks in sitting time/h, controlling for age, sex, and socioeconomic status. RESULTS: The number of breaks in sitting time significantly predicted a lower weight status (non-overweight) according to WC values (P for trend = 0.032) after adjustments. CONCLUSIONS: Breaking up sitting time was positively associated with toddlers' waist circumference. Future studies are needed to determine whether breaking up sitting time is a protective for cardiometabolic health in toddlers.

Environmental characteristics of early childhood education and care centres and young children's weight status: A systematic review.

The aim of this systematic review was to summarize ECEC environmental correlates of weight status in children under the age of 6years. Six databases (PubMed, PsycINFO, CINAHL, SPORTDiscus, Scopus, and Web of Science) were searched until March 2017. Observational studies examining the relationship between ECEC environmental characteristics and weight status in children aged 0-6years were included. Data was extracted using a predesigned form. Eight studies, representing 4862 children, met the inclusion criteria. Twenty-two environmental characteristics were identified and classified into four domains (physical, political, economic, and sociocultural); of these, six correlates were found. 'Active environment' 'sedentary opportunities', 'active play time', 'high sugar and high fat served', 'educators' weight' and 'educators' habitual physical activity level' were associated with weight status in young children. However, for most environmental characteristics examined, strong evidence is not available yet, due to variations across studies on the measures of environmental characteristics and analytical methodologies. Stronger empirical evidence in greater quantity is needed. Future studies in this area are recommended to investigate the environmental influence using an ecological approach and to examine the potential mediators, with a focus on the settings of family-based centres and samples representing toddlers and/or infants.

Compliance with the Australian 24-hour movement guidelines for the early years: associations with weight status.

BACKGROUND: For effective public health and surveillance it is important to document the proportion of young children who meet the new Australian Integrated 24 h Movement Guidelines for the Early Years and how these associate with health outcomes. We aimed to (i) assess compliance with the new Integrated 24 h Movement Guidelines for the Early Years in a sample of Australian toddlers; and (ii) ascertain whether compliance with the guidelines associates with weight status. METHODS: The sample comprised 202 toddlers (104 girls) aged 19.74 ± 4.07 months from the GET UP! STUDY: Participants wore accelerometers (Actigraph GT3X+) for 24 h over 7 consecutive days to assess physical activity, sedentary time and sleep. Parents reported participants' screen time. Weight and height were measured and body mass index (BMI) z-scores by age and sex were calculated. Analysis of Covariance (ANCOVA) was performed to test differences in BMI z-scores between participants complying with (i) none or any individual guideline, (ii) any combination of meeting two guidelines, and (iii) those who met all three guidelines, adjusting for child age, gender and socioeconomic status. RESULTS: Only 8.9% of the sample met the overall 24 h movement guidelines. Most of the sample met the physical activity (96.5%) and sleep (79.7%) guidelines but only 11.4% met the sedentary behavior guideline. Average BMI Z-scores did not significantly differ between children who complied with none or any individual guideline, any combination of meeting two guidelines, and those who met all three guidelines (p > 0.05). Although the lack of significant differences, participants who accomplished any combination of two guidelines or all three guidelines appear to have had a lower BMI Z-score than those complying with one of the guidelines or none. CONCLUSIONS: Just under 9% of our sample met the overall Australian 24 h Movement Guidelines for the Early Years. BMI was not associated with the accomplishment of any of the 24-h Movement Guidelines. Strategies to promote adherence to the 24-h movement guidelines in toddlers, particularly for screen time, are necessary, as promoting health-related behaviors in early childhood has the potential to provide children a strong foundation for lifelong physical and mental health.

A collaborative approach to adopting/adapting guidelines - The Australian 24-Hour Movement Guidelines for the early years (Birth to 5 years): an integration of physical activity, sedentary behavior, and sleep.

BACKGROUND: In 2017, the Australian Government funded the update of the National Physical Activity Recommendations for Children 0-5 years, with the intention that they be an integration of movement behaviours across the 24-h period. The benefit for Australia was that it could leverage research in Canada in the development of their 24-h guidelines for the early years. Concurrently, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group published a model to produce guidelines based on adoption, adaption and/or de novo development using the GRADE evidence-to-decision framework. Referred to as the GRADE-ADOLOPMENT approach, it allows guideline developers to follow a structured and transparent process in a more efficient manner, potentially avoiding the need to unnecessarily repeat costly tasks such as conducting systematic reviews. The purpose of this paper is to outline the process and outcomes for adapting the Canadian 24-Hour Movement Guidelines for the Early Years to develop the Australian 24-Hour Movement Guidelines for the Early Years guided by the GRADE-ADOLOPMENT framework. METHODS: The development process was guided by the GRADE-ADOLOPMENT approach. A Leadership Group and Consensus Panel were formed and existing credible guidelines identified. The draft Canadian 24-h integrated movement guidelines for the early years best met the criteria established by the Panel. These were evaluated based on the evidence in the GRADE tables, summaries of findings tables and draft recommendations from the Canadian Draft Guidelines. Updates to each of the Canadian systematic reviews were conducted and the Consensus Panel reviewed the evidence for each behaviour separately and made a decision to adopt or adapt the Canadian recommendations for each behaviour or create de novo recommendations. An online survey was then conducted (n = 302) along with five focus groups (n = 30) and five key informant interviews (n = 5) to obtain feedback from stakeholders on the draft guidelines. RESULTS: Based on the evidence from the Canadian systematic reviews and the updated systematic reviews in Australia, the Consensus Panel agreed to adopt the Canadian recommendations and, apart from some minor changes to the wording of good practice statements, keep the wording of the guidelines, preamble and title of the Canadian Guidelines. The Australian Guidelines provide evidence-informed recommendations for a healthy day (24-h), integrating physical activity, sedentary behaviour (including limits to screen time), and sleep for infants (<1 year), toddlers (1-2 years) and preschoolers (3-5 years). CONCLUSIONS: To our knowledge, this is only the second time the GRADE-ADOLOPMENT approach has been used. Following this approach, the judgments of the Australian Consensus Panel did not differ sufficiently to change the directions and strength of the recommendations and as such, the Canadian recommendations were adopted with very minor alterations. This allowed the Guidelines to be developed much faster and at lower cost. As such, we would recommend the GRADE-ADOLOPMENT approach, especially if a credible set of guidelines, with all supporting materials and developed using a transparent process, is available. Other countries may consider using this approach when developing and/or revising national movement guidelines.

"GET-UP" study rationale and protocol: a cluster randomised controlled trial to evaluate the effects of reduced sitting on toddlers' cognitive development.

BACKGROUND: The educational and cognitive differences associated with low socioeconomic status begin early in life and tend to persist throughout life. Coupled with the finding that levels of sedentary time are negatively associated with cognitive development, and time spent active tends to be lower in disadvantaged circumstances, this highlights the need for interventions that reduce the amount of time children spend sitting and sedentary during childcare. The proposed study aims to assess the effects of reducing sitting time during Early Childhood Education and Care (ECEC) services on cognitive development in toddlers from low socio-economic families. METHODS/DESIGN: We will implement a 12-months 2-arm parallel group cluster randomised controlled trial (RCT) with Australian toddlers, aged 12 to 26 months at baseline. Educators from the ECEC services allocated to the intervention group will receive professional development on how to reduce sitting time while children attend ECEC. Participants' cognitive development will be assessed as a primary outcome, at baseline and post-intervention, using the cognitive sub-test from the Bayley Scales of Infant and Toddler Development. DISCUSSION: This trial has the potential to inform programs and policies designed to optimize developmental and health outcomes in toddlers, specifically in those from disadvantaged backgrounds. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12616000471482 , 11/04/2016, retrospectively registered.

Beyond the Jump: A Scoping Review of External Training Load Metrics in Volleyball.

CONTEXT: Volleyball is a complex sport involving multifaceted movements and high-velocity actions, leading to diverse external training loads (ETLs) that have profound implications for player performance and injury risk. OBJECTIVE: To provide a comprehensive overview of the measurement of ETL in volleyball, identify gaps in current understanding, and offer valuable insights for stakeholders in the field. DATA SOURCES: The literature search was conducted across the following electronic databases: PubMed/Medline, Scopus, Web of Science, and SPORTDiscus. STUDY SELECTION: Studies were selected based on their relevance to the measurement of ETL in volleyball. STUDY DESIGN: A scoping review methodology was chosen to map and summarize the broad body of literature related to ETL measurement in volleyball. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Data related to ETL measurements in volleyball were extracted and analyzed from the selected studies, focusing on metrics utilized, player positions examined, and technologies employed. RESULTS: A total of 18 studies related to ETL in volleyball were identified and examined for this review. Despite the importance of sagittal plane movements in volleyball, the review identified a substantial research gap regarding ETL measurements beyond this plane, as well as a lack of focus on the unique demands of different player positions like the liberos. The use of technologies such as inertial measurement units was prevalent, but more comprehensive measurement methods are needed. CONCLUSION: There is a critical need for diversified ETL metrics in volleyball, extending beyond the conventional sagittal plane measurements. The findings highlight a substantial research gap in addressing the unique demands of different player positions, notably the liberos. This study underscores the importance of incorporating multiplanar movement data, player-specific roles, and advanced measurement technologies to develop more tailored training programs and injury prevention strategies.

Study of Body Composition and Motor Skills of Futsal Athletes of Different Competitive Levels.

This study aimed to verify whether there are differences in the body composition, functionality, lower-limb power, agility, and cardiorespiratory capacity in futsal players, comparing futsal athletes by competitive level. The athletes (N = 84) were divided into three groups: group Elite (N = 29), group Sub-Elite (N = 29), and group Non-Elite (N = 26). Anthropometric variables were analyzed through a bioimpedance scale (Inbody 270), and functionality was analyzed through a functional movement screen battery. The power of the lower limbs was tested with the Abalakov jump, the agility with the zigzag agility test, and the cardiorespiratory capacity through the futsal intermittent endurance test. Anthropometric data from futsal athletes revealed a homogeneity in relation to the variables analyzed, regardless of the level of competition in which they operate. In performance variables, the power of the members and functionality was considered a discriminating factor of the level of competitiveness of the athletes, with the Elite group athletes presenting the best values. We concluded that there were no differences in relation to the body composition of the athletes. However, the athletes of higher levels, as a rule, present better performances in physiological aspects, results that can be explained by the fact that there is a better periodization in terms of training, with more intense loads and more complex competitive calendars, thus resulting in a greater specialization of these athletes.

Training stress, neuromuscular fatigue and well-being in volleyball: a systematic review.

BACKGROUND: Volleyball, with its unique calendar structure, presents distinct challenges in training and competition scheduling. Like many team sports, volleyball features an unconventional schedule with brief off-season and pre-season phases, juxtaposed against an extensive in-season phase characterized by a high density of matches and training. This compact calendar necessitates careful management of training loads and recovery periods. The effectiveness of this management is a critical factor, influencing the overall performance and success of volleyball teams. In this review, we explore the associations between training stress measures, fatigue, and well-being assessments within this context, to better inform future research and practice. METHODS: A systematic literature search was conducted in databases including PsycINFO, MEDLINE/PubMed, SPORTDiscus, Web of Science, and Scopus. Inclusion criteria were original research papers published in peer-reviewed journals involving volleyball athletes. RESULTS: Of the 2535 studies identified, 31 were thoroughly analysed. From these 31 articles, 22 included professional athletes, seven included collegiate-level volleyball athletes, and two included young athletes. Nine studies had female volleyball players, while the remaining 22 had male volleyball athletes. CONCLUSIONS: Internal training load should be collected daily after training sessions and matches with the session rating of perceived exertion method. External training load should also be measured daily according to the methods based on jump height, jump count, and kinetic energy. If force platforms are available, neuromuscular fatigue can be assessed weekly using the FT:CT ratio of a countermovement jump or, in cases where force platforms are not available, the average jump height can also be used. Finally, the Hooper Index has been shown to be a measure of overall wellness, fatigue, stress, muscle soreness, mood, and sleep quality in volleyball when used daily.

Subjective and Objective Monitoring Markers: Are They Related to Game Performance Indicators in Elite Female Volleyball Players?

PURPOSE: This cohort study aimed to investigate the relationship between subjective (wellness and internal training load [ITL]) and objective (neuromuscular fatigue) monitoring markers and performance aspects (reception quality [RQ] and attack efficiency [AE]) in professional female volleyball players. METHODS: The study was conducted over an 8-week period during the final mesocycle of the competitive phase. A total of 24 training sessions and 10 matches were included in the analysis. Subjective measures of wellness and ITL were assessed, and neuromuscular fatigue was evaluated using countermovement-jump (CMJ) height. RQ and AE were determined based on game statistics. RESULTS: The study found a positive relationship between wellness and RQ, particularly affecting outside hitters and liberos. ITL showed a positive association with AE, primarily impacting outside hitters, opposite hitters, and middle blockers. Additionally, ITL demonstrated a negative correlation with RQ, mainly affecting outside hitters and liberos. CMJ performance was associated with AE, where a decrease in CMJ height was linked to reduced AE. CONCLUSIONS: The findings highlight the importance of considering players' wellness scores in training and match strategies for different positions. Careful management of training loads, considering both physical and technical demands, is crucial for optimizing performance outcomes. Monitoring neuromuscular fatigue, as indicated by CMJ performance, is particularly relevant for outside hitters, opposite hitters, and middle blockers involved in attack actions. Coaches, trainers, and sports practitioners can use these insights to develop position-specific training protocols and implement effective strategies for maintaining or improving performance metrics under various stressors.

Effects of a Velocity-Based Complex Training Program in Young Female Artistic Roller Skating Athletes.

Complex training consists of a near maximal strength effort followed by a biomechanically similar explosive exercise. One of many complex training methods that have been proposed is the French Contrast Method. The aim of this study was to analyze the effects of the French Contrast Method on maximal strength and power of young female artistic roller skating athletes with the help of velocity-based training to prescribe the intervention program. Eighteen female artistic roller skating athletes, divided into an experimental group (EG) and a control group (CG), participated in this study. The EG performed complex training via the French Contrast Method. The CG did not perform any additional training besides their regular roller skating practices. All participants were tested on the 1-RM back squat and hip thrust, the load-velocity profile assessment of both exercises previously stated, the countermovement jump, and the drop jump. A significant increase in mean concentric velocity (MCV) of the hip thrust exercise from 10 to 60% of 1-RM in the EG was observed. Significant differences between groups were observed for the MCV of the hip thrust from 10 to 90% of 1-RM. There were also significant increases in the 1-RM back squat and 1-RM hip thrust over time in the EG. For the vertical jump variables, there were significant differences between groups for both contact time and the reactive strength index with and without an arm swing. The results of this study suggest that a 6-week training intervention with the use of the French Contrast Method can significantly improve maximal strength and power.

Rating of Perceived Exertion in Professional Volleyball: A Systematic Review.

The rating of perceived exertion (RPE) is a non-invasive, cost effective, and time efficient strategy to measure training loads. However, data can be collected without following specific procedures and across a range of methods (e.g., different RPE scales and/or different operational questions). Consequently, practitioners working in professional volleyball can use this information in various ways with different assessment standards between them. Therefore, the purpose of the current review was to systematically and critically evaluate the use of RPE-based methods in professional volleyball athletes. Electronic searches were conducted in four databases (PubMed, SPORTDiscus, Scopus, and Web of Science). The electronic search yielded 442 articles, from which 14 articles were included in the systematic review. All included studies used the BORG-CR10 scale to calculate the session RPE. The main findings indicate that, to minimize the effect of the last exercise of the session, the athlete should be presented with the RPE question 10 to 30 minutes after the session is finished. Additionally, in order to evaluate the intensity of the training session, the question should be "how hard/intense was your session?", avoiding questions without these adverbs or adjectives such as "how was your training session/workout?". Future studies should analyse the collection of the localized RPE responses in professional volleyball athletes and their relationships with objective markers such as the number of jumps and accelerations.

Training Load, Neuromuscular Fatigue, and Well-Being of Elite Male Volleyball Athletes During an In-Season Mesocycle.

PURPOSE: Most high-intensity bouts of exercise in volleyball consist of jumping activities, which are responsible for inducing muscle damage, high levels of fatigue, and muscle soreness. Therefore, the aim of the current study was to quantify and analyze the training loads, neuromuscular fatigue, and perceptual well-being of a 5-week in-season mesocycle carried out by a professional male volleyball team. METHODS: Fifteen volleyball players (age 28.51 [5.39] y; height 193.19 [9.87] cm; body mass 88.46 [13.18] kg) participated in this study. Internal training load assessed through the rating of perceived exertion, external training load (ETL; evaluated using an inertial motion unit), countermovement jump (CMJ) height and peak power, and wellness questionnaire responses were obtained from all athletes. RESULTS: Results indicated a progressive decrease of the internal training load during the week and by the undulatory pattern of the ETL during the microcycles. Moreover, training monotony increased across the microcycles and was negatively associated with CMJ peak power (r = -.681, P < .05). Finally, sleep quality (ρ = -.747, P < .01) and fatigue (ρ = -.789, P < .01) were negatively associated with weekly ETL. CONCLUSIONS: This study indicated that sleep quality and fatigue were negatively associated with weekly ETL. Therefore, decreases in weekly ETL might be needed to improve sleep quality and decrease fatigue in professional volleyball players. Plus, higher values of training monotony were associated with lower values of CMJ peak power. Consequently, avoiding training monotony might be important to improve jumping performance in professional volleyball athletes.

Cosmetic emulsion based on the fucose-rich polysaccharide FucoPol: Bioactive properties and sensorial evaluation.

In this study, the physicochemical characteristics, bioactive properties, and sensorial evaluation of a O/W cosmetic formulation containing FucoPol, a fucose-containing bacterial polysaccharide, were assessed. The stability of the FucoPol-based cream, named F-cream, was demonstrated over a period of 2 months at different temperatures (4, 20 and 30 °C), during which it maintained the organoleptic characteristics and pH (5.88-6.19), with minimal variations on the apparent viscosity. Furthermore, no breaking mechanisms occurred upon centrifuging the samples (accelerated stability test) kept at 4 °C and at 30 °C for 60 days. The F-cream presented a shear-thinning and solid-liquid behavior consistent with its envisaged use for topical applications, proving to be a suitable candidate for an anti-aging application due to its antioxidant capacity and effective photoprotection, maintaining cellular preservation. Moreover, the formulation was proven non-cytotoxic for HaCaT cells at concentrations between 0.78 and 12.5 mg/mL, promoting HFFF2 cell migration (46-70 % of wound closure) at a concentration of 2.5 mg/mL, and HaCaT cell migration at a concentration of 10 mg/mL (95-98 % of wound closure). Upon application over the skin, the F-cream provided a hydration and softness with desired spreadability with no residues after application. These findings show that FucoPol has good potential to be used as a functional and/or active ingredient in cosmetic formulations, forming an emulsified cream with appealing sensorial properties that can act as a moisturizer with photoprotection, antioxidant, and regeneration properties.

Lower Limbs Wearable Sports Garments for Muscle Recovery: An Umbrella Review.

This review aims to understand the different technologies incorporated into lower limbs wearable smart garments and their impact on post-exercise recovery. Electronic searches were conducted in the PubMed, Web of Science, and Cochrane electronic databases. Eligibility criteria considered meta-analyses that examined the effects of wearable smart garments on physical fitness in healthy male and female adults. Seven meta-analyses were considered in the current umbrella review, indicating small effects on delayed-onset muscle soreness ([0.40-0.43]), rate of perceived exertion (0.20), proprioception (0.49), anaerobic performance (0.27), and sprints ([0.21-0.37]). The included meta-analyses also indicated wearable smart garments have trivial to large effects on muscle strength and power ([0.14-1.63]), creatine kinase ([0.02-0.44]), lactate dehydrogenase (0.52), muscle swelling (0.73), lactate (0.98) and aerobic pathway (0.24), and endurance (0.37), aerobic performance (0.60), and running performance ([0.06-6.10]). Wearing wearable smart garments did not alter the rate of perceived exertion and had a small effect on delayed-onset muscle soreness. Well-fitting wearable smart garments improve comfort and kinesthesia and proprioception and allow a reduction in strength loss and muscle damage after training and power performance following resistance training or eccentric exercise.

Associations of sleep characteristics with cognitive and gross motor development in toddlers.

OBJECTIVE: To examine cross-sectional associations of sleep characteristics (duration, consolidation, timing, variability) with cognitive and gross motor development in toddlers. METHODS: Participants were 205 toddlers (19.6 ± 4.3 months) from the GET-UP! STUDY: Nap/nighttime sleep onset and offset were measured using an accelerometer and used to calculate nap/nighttime sleep duration. Total sleep duration was calculated and classified as meeting or not meeting the sleep recommendation of the Australian 24-Hour Movement Guidelines (11-14 h/d). Nighttime sleep ratio (ie, nighttime sleep duration: total sleep duration), indicative of consolidation, was expressed as a percent value. Nighttime sleep midpoint (ie, the midpoint between nighttime sleep onset and offset), indicating the lateness of sleep schedules, was converted to a decimal hour. For sleep variability, the intraindividual standard deviation of nighttime sleep duration and nighttime sleep midpoint was calculated, respectively. Cognitive development (Bayley Scales of Infant and Toddler Development-III) and specific domains of gross motor development (Peabody Developmental Motor Scales, 2nd edition) were measured. RESULTS: Shorter nap duration (B = -0.87, 95%CI: -1.71, -0.02) and higher nighttime sleep ratio (B = 0.13, 95% CI: 0.02, 0.24) were associated with better cognitive development. Regarding gross motor development, positive associations were found for nighttime sleep duration (object manipulation: B = 0.26, 95% CI: 0.01, 0.51; gross motor quotient: B = 1.21, 95% CI: 0.04, 2.38) and total sleep duration (object manipulation: B = 0.28, 95% CI: 0.03, 0.52); negative associations were found for nighttime sleep midpoint (stationary: B = -0.31; 95% CI: -0.58, -0.06) and nighttime sleep duration variability (stationary: B = -0.32, 95% CI: -0.64, -0.004). CONCLUSIONS: In toddlers, more consolidated sleep may be an indicator of better cognitive development. Promoting longer and more consistent nighttime sleep duration, as well as an earlier nighttime sleep schedule, may facilitate gross motor development. However, our findings for the associations of sleep characteristics with cognitive and gross motor development need to be confirmed in prospective studies.

How to Improve the Reactive Strength Index among Male Athletes? A Systematic Review with Meta-Analysis.

The reactive strength index (RSI) describes the individual's capability to quickly change from an eccentric muscular contraction to a concentric one and can be used to monitor, assess, and reduce the risk of athlete's injury. The purpose of this review is to compare the effectiveness of different training programs on RSI. Electronic searches were conducted in MEDLINE, PubMed, Scopus, SPORTDiscus, and Web of Science from database inception to 11 February 2022. This meta-analysis was conducted in accordance with the recommendations of the preferred reporting items for systematic reviews and meta-analyses (PRISMA). The search returned 5890 records, in which 39 studies were included in the systematic review and 30 studies were included in the meta-analysis. Results from the randomized studies with the control group revealed that plyometric training improved RSI in adult athletes (0.84, 95% CI 0.37 to 1.32) and youth athletes (0.30, 95% CI 0.13 to 0.47). Evidence withdrawn from randomized studies without a control group revealed that resistance training also improved the RSI (0.44, 95% CI 0.08 to 0.79) in youth athletes but not in adults. Interventions with plyometric training routines have a relatively large, statistically significant overall effect in both adult and youth athletes. This supports the implementation of this type of interventions in early ages to better cope with the physical demands of the various sports. The impact of resistance training is very low in adult athletes, as these should seek to have a more power-type training to see improvements on the RSI. More interventions with sprint and combined training are needed.

Development of Olive Oil and α-Tocopherol Containing Emulsions Stabilized by FucoPol: Rheological and Textural Analyses.

Biobased raw materials like natural polysaccharides are increasingly sought by the cosmetic industry for their valuable properties. Such biodegradable and usually non-cytotoxic biopolymers are commonly used in skin-care products as rheological modifiers, bioemulsifiers and/or bioactive ingredients. FucoPol is a natural polysaccharide with reported biocompatibility, emulsion-forming and stabilizing capacity, shear-thinning behavior and bioactivity (e.g., antioxidant capacity, wound healing ability) that potentiate its utilization in skin-care products. In this study, olive oil and α-tocopherol containing emulsions were stabilized with FucoPol. Although the presence of α-tocopherol negatively impacted the emulsions' stability, it increased their emulsification index (EI). Moreover, FucoPol outperformed the commercial emulsifier Sepigel® 305, under the tested conditions, with higher EI and higher stability under storage for 30 days. The formulation of FucoPol-based emulsions with olive oil and α-tocopherol was studied by Response Surface Methodology (RSM) that allowed the definition of the ingredients' content to attain high emulsification. The RSM model established that α-tocopherol concentration had no significant impact on the EI within the tested ranges, with optimal emulsification for FucoPol concentration in the range 0.7-1.2 wt.% and olive oil contents of 20-30 wt.%. Formulations with 25 wt.% olive oil and either 0.5 or 2.0 wt.% α-tocopherol were emulsified with 1.0 wt.% or 0.7 wt.% FucoPol, respectively, resulting in oil-in-water (O/W) emulsions. The emulsions had similar shear-thinning behavior, but the formulation with higher FucoPol content displayed higher apparent viscosity, higher consistency, as well as higher firmness, adhesiveness and cohesiveness, but lower spreadability. These findings show FucoPol's high performance as an emulsifier for olive oil/α-tocopherol, which are supported by an effective impact on the physicochemical and structural characteristics of the emulsions. Hence, this natural polysaccharide is a potential alternative to other emulsifiers.