Quantifying demands on the hamstrings during high-speed running: A systematic review and meta-analysis.

INTRODUCTION: Hamstring strain injury (HSI) remains a performance, economic, and player availability burden in sport. High-speed running (HSR) is cited as a common mechanism for HSI. While evidence exists regarding the high physical demands on the hamstring muscles in HSR, meta-analytical synthesis of related activation and kinetic variables is lacking. METHODS: A systematic search of Medline, Embase, Scopus, CINAHL, SportDiscus, and Cochrane library databases was conducted in accordance with the PRISMA 2020 guidelines. Studies reporting hamstring activation (electromyographic [EMG]) or hamstring muscle/related joint kinetics were included where healthy adult participants ran at or beyond 60% of maximum speed (activation studies) or 4 m per second (m/s) (kinetic studies). RESULTS: A total of 96 studies met the inclusion criteria. Run intensities were categorized as "slow," "moderate," or "fast" in both activation and kinetic based studies with appropriate relative, and raw measures, respectively. Meta-analysis revealed pooled mean lateral hamstring muscle activation levels of 108.1% (95% CI: 84.4%-131.7%) of maximal voluntary isometric contraction (MVIC) during "fast" running. Meta-analysis found swing phase peak knee flexion internal moment and power at 2.2 Newton meters/kilogram (Nm/kg) (95% CI: 1.9-2.5) and 40.3 Watts/kilogram (W/kg) (95% CI: 31.4-49.2), respectively. Hip extension peak moment and power was estimated as 4.8 Nm/kg (95% CI: 3.9-5.7) and 33.1 W/kg (95% CI: 17.4-48.9), respectively. CONCLUSIONS: As run intensity/speed increases, so do the activation and kinetic demands on the hamstrings. The presented data will enable clinicians to incorporate more objective measures into the design of injury prevention and return-to-play decision-making strategies.

Movement Competency Screens Can Be Reliable In Clinical Practice By A Single Rater Using The Composite Score.

Background: Movement competency screens (MCSs) are commonly used by coaches and clinicians to assess injury risk. However, there is conflicting evidence regarding MCS reliability. Purpose: This study aimed to: (i) determine the inter- and intra-rater reliability of a sport specific field-based MCS in novice and expert raters using different viewing methods (single and multiple views); and (ii) ascertain whether there were familiarization effects from repeated exposure for either raters or participants. Study Design: Descriptive laboratory study. Methods: Pre-elite youth athletes (n=51) were recruited and videotaped while performing a MCS comprising nine dynamic movements in three separate trials. Performances were rated three times with a minimal four-week wash out between testing sessions, each in randomized order by 12 raters (3 expert, 9 novice), using a three-point scale. Kappa score, percentage agreement and intra-class correlation were calculated for each movement individually and for the composite score. Results: Fifty-one pre-elite youth athletes (15.0±1.6 years; n=33 athletics, n=10 BMX and n=8 surfing) were included in the study. Based on kappa score and percentage agreement, both inter- and intra-rater reliability were highly variable for individual movements but consistently high (>0.70) for the MCS composite score. The composite score did not increase with task familiarization by the athletes. Experts detected more movement errors than novices and both rating groups improved their detection of errors with repeated viewings of the same movement. Conclusions: Irrespective of experience, raters demonstrated high variability in rating single movements, yet preliminary evidence suggests the MCS composite score could reliably assess movement competency. While athletes did not display a familiarization effect after performing the novel tasks within the MCS for the first time, raters showed improved error detection on repeated viewing of the same movement. Level of Evidence: Cohort study.

The Relationship Between Habitual Physical Activity, Sitting Time, and Cognitive Function in Young Adult Women.

BACKGROUND: There is evidence that physical activity (PA), sitting time, and obesity may impact cognition, but few studies have examined this in young women. METHODS: Healthy women (18-35 y), without conditions that impair cognition, were recruited for this cross-sectional study. Participants completed anthropometric and validated computerized cognitive assessments (IntegNeuro™). Performance on 5 cognitive domains (impulsivity, attention, information processing, memory, and executive function) was reported as z scores. Sitting hours and weekly PA calculated from time in low-, moderate-, and high-intensity activity were obtained via the International Physical Activity Questionnaire. Analysis of variance/analysis of covariance, chi-square, and linear regression were used. RESULTS: 299 (25.9 [5.1] y) women (low PA = 19%; moderate PA = 40%; high PA = 41%) participated. High PA women had lower body mass index (high PA = 26.1 [6.5]; moderate PA = 30.0 [8.7]; low PA = 31.0 [11.1] kg/m2; P < .001) and less sitting time (high PA = 6.6 [3.1]; moderate PA = 7.7 [2.8]; low PA = 9.3 [3.6] hr/weekday; P < .0001). Cognitive function was within normal ranges and did not differ between any PA groups (P = .42). Adjusting for body mass index, C-reactive protein, or sitting hours did not alter results. Weak correlations were found between time in high-intensity activity and impulsivity (b = 0.12, r2 = .015; P = .04), and between sitting hours and information processing efficiency (b = -0.18, r2 = .03; P = .002). Valuesare presented as mean (SD). CONCLUSIONS: Cognitive function was within the normal range, regardless of PA or sitting time.

Association between Obesity and Omega-3 Status in Healthy Young Women.

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are essential for healthy development and protect against metabolic disease. However, individuals with obesity may be pre-disposed to experiencing lower n-3 PUFA status than normal-weight individuals. This cross-sectional study examined the relationship between the omega-3 index (O3I), body mass index (BMI) and dietary intake in healthy young women (n = 300; age = 18-35 y), a group not previously focused on. Intake was adjusted for energy using the residuals method, and associations were explored using independent t-tests and Pearson's correlations. Participants with obesity were found to have significantly lower O3I than normal-weight participants (p < 0.0001); however, no significant differences were observed in mean n-3 PUFA intakes. Even so, energy-adjusted intakes of n-3 PUFAs, with the exception of alpha-linolenic acid, were significantly correlated with O3I. This study demonstrates that O3I is influenced by both BMI and diet in young women; however the relationship between these two variables may be complex. Current intakes of n-3 PUFA observed in young women may not be effective in achieving target O3I levels in those with obesity, and further research is needed to find effective ways of improving n-3 PUFA status in a group already at increased risk of metabolic disease.

A biomechanical comparison of conventional classifications of bowling action-types in junior fast bowlers.

Fast bowling is categorised into four action types: side-on, front-on, semi-open and mixed; however, little biomechanical comparison exists between action types in junior fast bowlers. This study investigated whether there are significant differences between action-type mechanics in junior fast bowlers. Three-dimensional kinematic and kinetic analyses were completed on 60 junior male fast bowlers bowling a five-over spell. Mixed-design factorial analyses of variance were used to test for differences between action-type groups across the phases of the bowling action. One kinetic difference was observed between groups, with a higher vertical ground reaction force loading rate during the front-foot contact phase in mixed and front-on compared to semi-open bowlers; no other significant group differences in joint loading occurred. Significant kinematic differences were observed between the front-on, semi-open and mixed action types during the front-foot contact phase for the elbow and trunk. Significant kinematic differences were also present for the ankle, T12-L1, elbow, trunk and pelvis during the back-foot phase. Overall, most differences in action types for junior fast bowlers occurred during the back-foot contact phase, particularly trunk rotation and T12-L1 joint angles/ranges of motion, where after similar movement patterns were utilized across groups during the front-foot contact phase.

Effectiveness of Active Learning that Combines Physical Activity and Math in Schoolchildren: A Systematic Review.

BACKGROUND: Despite increased interest in combining learning and physical activity (PA), the academic and PA benefits of active learning are uncertain. METHODS: A systematic search of 5 databases for studies combining learning math with PA in primary/elementary schools was conducted. Academic benefit was evaluated by pre-post intervention math scores compared to a control group. Effect sizes (ES) were extracted/calculated when possible. Due to study heterogeneity, meta-analysis was not conducted. RESULTS: Six randomized controlled trials and 5 quasi-experimental studies evaluating 4082 participants (53% girls; mean age 7.5-11.1 years) were eligible. Math scores were significantly better in the intervention group in 6 of 11 studies on at least 1 test (ES: 0.42-4.7; p ≤ .03). Other math tests either were not all statistically significant (2 studies) or the benefit varied across grades (1 study). No studies reported a decline in math scores. Of studies measuring PA with accelerometers, 4 of 5 reported significantly greater PA in the intervention group during the intervention (p < .05) or across the school day (p < .01). CONCLUSIONS: Undertaking PA while learning was largely equivocal for math scores but showed promising results for increasing daily PA, without detrimental effects on math performance. The need for more rigorous studies with comprehensive assessment of academic performance and PA is highlighted.

Whole-body kinematics and coordination in a complex dance sequence: Differences across skill levels.

This study examined differences across skill levels in the kinematics of a complex, whole-body, asymmetrical, cyclical dance sequence, the 'Alternate Basic' in Cha-Cha-Cha, to determine whether observed differences were consistent with Bernstein's (1967) model of development of coordination. Bernstein proposed that with novel motor skills, beginners move their bodies rigidly and spastically, freezing kinematic degrees of freedom (DOF) to constrain the motor system. As the skill becomes practised, the DOF unfreeze and movements become more dynamic, allowing the integration of reactional elements (passive forces, moments, etc.) and organisation of more complex coordinative structures. Twenty-nine dancers - beginners (n = 10), intermediates (n = 10), experts (n = 9) - performed 12 cycles of the dance sequence (total duration ~60 s). Three-dimensional kinematic data from 36 joint angles were collected using a 14-camera infrared motion capture system. Most joints displayed increased amplitude and speed of movement, especially early in skill progression (beginner-intermediate stage), with no evidence of any decreases, showing that unfreezing occurred around the general movement pattern early. Speed of movement continued to increase later (intermediate-expert stage), as well as further unfreezing of the upper limbs. Changes to intra-limb couplings were limited, comprising some early reductions in coupling strength. Principal component analyses (PCA) showed that the structure of movement became more organised with increased skill. There was an early reduction in the number of coordinative structures, while later, movement was integrated more into the first coordinative structure. As predicted by Bernstein's coordination development model, therefore, the kinematic DOF unfroze as skill level progressed, leading to increased organisation of coordinative structures. The results of this study support the importance of a whole-body perspective in studies of coordination, with incorporation of kinetic variables in future research in order to examine the role that reactional elements play in motor skill development.

What do young women with obesity want from a weight management program?

PURPOSE: Early adulthood is a high-risk time for weight gain; however, young women with obesity are difficult to recruit to weight management programs. To encourage participation and retention, it is important to understand what young women want from these programs. The purpose of the study was to explore participants' perspectives on the features of an ideal weight management program. METHODS: Semi-structured interview schedules were used to elicit information from eight focus groups [27 women; mean age of 29.1 (± 5.1) years, mean body mass index (BMI; kg/m2) of 35.8 (± 2.9)]. The focus groups were transcribed, coded and analyzed qualitatively. RESULTS: The themes that emerged were program content, format, program characteristics, program name, location and duration. A major finding from the study is that participants value a program that includes nutritional, psychological and lifestyle interventions, and includes components that are not traditionally part of weight management programs such as body acceptance, sexual health and dressing and grooming. A program name that conveys wellness and body positivity was valued. Participants highlighted the importance of individualized programs that are also tailored to the needs of young adults, and delivered by credible and approachable staff who provide accountability. Cost-effectiveness, flexibility, accessibility, time-commitment were important considerations and the use of a combination of virtual and in-person methods (including group interventions) appealed to this cohort. CONCLUSION: Knowledge of program features which resonate with young women facilitates development of innovative ways to engage and support evidence-based weight management in this vulnerable group. LEVEL OF EVIDENCE: V.

Omega-3 polyunsaturated fatty acids status and cognitive function in young women.

BACKGROUND: Research indicates that low omega-3 polyunsaturated fatty acid (n-3 PUFA) may be associated with decreased cognitive function. This study examined the association between n-3 PUFA status and cognitive function in young Australian women. METHODS: This was a secondary outcome analysis of a cross-sectional study that recruited 300 healthy women (18-35 y) of normal weight (NW: BMI 18.5-24.9 kg/m2) or obese weight (OB: BMI ≥30.0 kg/m2). Participants completed a computer-based cognition testing battery (IntegNeuro™) evaluating the domains of impulsivity, attention, information processing, memory and executive function. The Omega-3 Index (O3I) was used to determine n-3 PUFA status (percentage of EPA (20:5n-3) plus DHA (22:6n3) in the red cell membrane) and the participants were divided into O3I tertile groups: T1 < 5.47%, T2 = 5.47-6.75%, T3 > 6.75%. Potential confounding factors of BMI, inflammatory status (C-reactive Protein), physical activity (total MET-min/wk), alpha1-acid glycoprotein, serum ferritin and hemoglobin, were assessed. Data reported as z-scores (mean ± SD), analyses via ANOVA and ANCOVA. RESULTS: Two hundred ninety-nine women (26.9 ± 5.4 y) completed the study (O3I data, n = 288). The ANOVA showed no overall group differences but a significant group × cognition domain interaction (p < 0.01). Post hoc tests showed that participants in the low O3I tertile group scored significantly lower on attention than the middle group (p = 0.01; ES = 0.45 [0.15-0.74]), while the difference with the high group was borderline significant (p = 0.052; ES = 0.38 [0.09-0.68]). After confounder adjustments, the low group had lower attention scores than both the middle (p = 0.01) and high (p = 0.048) groups. These findings were supported by univariate analyses which found significant group differences for the attention domain only (p = 0.004). CONCLUSIONS: Cognitive function in the attention domain was lower in women with lower O3I, but still within normal range. This reduced but normal level of cognition potentially provides a lower baseline from which cognition would decline with age. Further investigation of individuals with low n-3 PUFA status is warranted.

Whole-body angular momentum in a complex dance sequence: Differences across skill levels.

Due to the redundant degrees of freedom (DOF) and nonlinearity of reactional kinetic elements within the human motor apparatus, controlling the complex dynamics of the human musculoskeletal system presents considerable difficulties. Based on this challenge, Bernstein (1967) viewed skill development as the process whereby the central nervous system (CNS) gains mastery of kinematic DOF and kinetic reactional elements (passive forces, moments etc.), with the highest level of skill characterised by optimal exploitation of reactional elements in the achievement of movement goals. A previous kinematic investigation into coordination differences in a complex multidirectional dance sequence demonstrated that general unfreezing of kinematic DOF occurred as dance skill progressed (Chang et al., submitted for publication). To gain insight into the role of angular reactional elements in skill, the present kinetic study investigated angular momentum and associated variables across three skill levels (beginners, intermediates, experts) within this same complex dance sequence. The results showed that the angular momenta of segments and accompanying angular reactional elements generally increased with skill level. More specifically, the findings suggested that while improvements in movement economy from cancellation of angular momentum between body segments occur early in skill progression, later in skill progression, experts utilise increased whole-body angular momentum. Although this is energetically expensive, it may enhance the aesthetic value of dance movements, and/or have mechanical advantages. Overall, the findings here provide support for Bernstein's (1967) model of skill development. Future research should quantify the relations between energy expenditure, key biomechanical variables that reflect skill and dance aesthetics as perceived by audiences.

Caution using data from triaxial accelerometers housed in player tracking units during running.

Usage of accelerometers within player tracking devices in sport to quantify load, vertical ground reaction force (vGRF) or energy expenditure is contrary to placement guidelines. This study aimed to determine whether trunk-mounted accelerometers were a valid and reliable method to estimate thoracic segment or centre of gravity (COG) acceleration or vGRF, and the whether the elasticised harness contributes to the overestimation of acceleration. Ten male amateur rugby players performed five linear running tasks per lower limb at three speeds, twice, each with a different player tracking unit. Three-dimensional data were recorded and triaxial accelerometers were attached lateral to the device on the harness and skin and both shanks. Accelerometers demonstrated poor reliability (ICC:0.0-0.67), high variability (CV%:14-33%) and change in mean (41-160%), and were not valid to estimate vertical acceleration of the COG and thoracic segment nor vGRF. Caution is advised when utilising trunk-mounted triaxial accelerometer data as it is not a valid or reliable means to estimate peak vertical acceleration for its thoracic location nor whole-body COG acceleration or vGRF during running. To improve player tracking instrument validity and reliability, a new attachment method and/or harness material(s), that reduce or eliminate extraneous acceleration during running, are urgently required.

Recruiting young women to weight management programs: Barriers and enablers.

AIM: Recruiting young women to weight management research programs is difficult. The purpose of this study was to gain insights into the barriers and motivators that influence participation and to explore effective methods of recruitment from the perspective of young women with obesity living in both urban and regional areas. METHODS: Semi-structured interviews were used to elicit information from focus groups. The interviews were transcribed, coded and analysed qualitatively. Eight focus groups, which included a total of 27 women, were conducted. Participants had a mean age of 29.1 (±5.1) years and a mean body mass index of 35.8 (±2.9) kg/m2 . RESULTS: The barriers to participation were multifaceted and largely similar across urban and regional participants. Fear of judgement and uncertainty about the process were major psychosocial barriers. A lack of tailoring of program content was an important program-related barrier. Physical barriers such as time commitment, cost and access were discussed extensively, particularly in urban groups. The provision of incentives and the use of positive language that focusses on the benefits of the intervention were viewed positively. Physical and virtual methods of recruitment were identified as potentially effective provided they were presented in media that this group is likely to use and can access in a private location. CONCLUSIONS: The results of this study provide a greater understanding of the challenges faced by young women in relation to participation in weight management programs and some of the potential methods that could be utilised to facilitate participation.

Synergies in coordination: a comprehensive overview of neural, computational, and behavioral approaches.

At face value, the term "synergy" provides a unifying concept within a fractured field that encompasses complementary neural, computational, and behavioral approaches. However, the term is not used synonymously by different researchers but has substantially different meanings depending on the research approach. With so many operational definitions for the one term, it becomes difficult to use as either a descriptive or explanatory concept, yet it remains pervasive and apparently indispensable. Here we provide a summary of different approaches that invoke synergies in a descriptive or explanatory context, summarizing progress, not within the one approach, but across the theoretical landscape. Bernstein's framework of flexible hierarchical control may provide a unifying framework here, since it can incorporate divergent ideas about synergies. In the current motor control literature, synergy may refer to conceptually different processes that could potentially operate in parallel, across different levels within the same hierarchical control scheme. There is evidence for the concurrent existence of synergies with different features, both "hard-wired" and "soft-wired," and task independent and task dependent. By providing a comprehensive overview of the multifaceted ideas about synergies, our goal is to move away from the compartmentalization and narrow the focus on one level and promote a broader perspective on the control and coordination of movement.

The effects of multi-stage exercise with and without concurrent cognitive performance on cardiorespiratory and cerebral haemodynamic responses.

INTRODUCTION: Studies of cerebral haemodynamics have shown changes with increased exercise intensity, but the patterns have been highly variable and reliable associations with cognitive performance have not been identified. The aim of this study was to examine whether exercise-induced changes in oxygenated haemoglobin (O2Hb) led to changes in concomitant cognitive performance. METHODS: This study examined cardiorespiratory and cerebral haemodynamics during multi-stage exercise from rest to exhaustion, with (Ex + C) and without (Ex) concurrent cognitive performance (Go/No-go task). RESULTS: The presence of the cognitive task affected both cardiorespiratory and cerebral haemodynamics. The patterns in the cerebral haemodynamics during Ex and Ex + C diverged above the respiratory compensation threshold (RCT), but differences were significant only at 100% [Formula: see text], displaying increased deoxygenated haemoglobin (HHb), decreased difference between oxygenated and deoxygenated haemoglobin (HbDiff), and decreased cerebral oxygenation (COx) during Ex + C. More complex haemodynamic trends against intensity during Ex + C suggested that the presence of a cognitive task increases cerebral metabolic demand at high exercise intensities. The levels of O2Hb, HHb, HbDiff and total haemoglobin increased most steeply at intensities around the RCT during both Ex and Ex + C, but these changes were not accompanied by improved cognitive performance. CONCLUSION: The primary hypothesis, that cognitive performance would match changes in O2Hb, was not supported. Small variations in reaction time and response accuracy across exercise intensities were not significant, suggesting that cognitive performance is unaffected by intense short-duration exercise. Our results add further evidence that exercise-induced changes in cerebral haemodynamics do not affect cognitive performance.

Learning "Math on the Move": Effectiveness of a Combined Numeracy and Physical Activity Program for Primary School Children.

BACKGROUND: Physically active learning that combines physical activity with core curriculum areas is emerging in school-based health interventions. This study investigates the effectiveness of learning an important numeracy skill of times tables (TT) while concurrently engaging in aerobic activity compared with a seated classroom approach. METHODS: Grade-4 primary school students were randomly allocated to physical activity (P) or classroom (C) groups and received the alternate condition in the following term. P group received moderate to vigorous exercise (20 min, 3 times per week, 6 wk) while simultaneously learning selected TT. C group received similar learning, but seated. Changes in TT accuracy, general numeracy, aerobic fitness, and body mass index were assessed. Data were expressed as mean (SEM) and between-condition effect size (ES; 95% confidence interval). RESULTS: Participants [N = 85; 55% male, 9.8 (0.3) y, 36.4% overweight/obese] improved similarly on TT in both conditions [C group: 2.2% (1.1%); P group: 2.5% (1.3%); ES = 0.03; -0.30 to 0.36; P = .86]. Improvement in general numeracy was significantly greater for P group than C group [C group: 0.7% (1.2%); P group: 5.3% (1.4%); ES = 0.42; 0.08 to 0.75; P < .03]. An improvement in aerobic fitness for P group (P < .01) was not significantly greater than C group [C group: 0.8 (0.6); P group: 2.2 (0.5) mL·kg·min-1; ES = 0.32; -0.01 to 0.66; P = .06]. Body mass index was unchanged. CONCLUSION: Combined movement with learning TT was effective. Physically active learning paradigms may contribute to meeting daily physical activity guidelines while supporting or even boosting learning.

Association between Haem and Non-Haem Iron Intake and Serum Ferritin in Healthy Young Women.

Iron is an essential micronutrient for human health and inadequate intake may result in iron deficiency (ID) or iron deficiency anaemia (IDA). Unlike other recent studies investigating iron status in young women, this cross-sectional study analysed dietary intake and biochemical data from healthy young (18-35 years) women (n = 299) to determine the association between both haem iron (HI) and non-haem iron (NHI) intakes and serum ferritin (SF). Dietary restraint and possible inflammation secondary to obesity were also measured and accounted for, and energy intake was adjusted for using the residuals method. Independent samples t-tests and chi-squared tests were performed, and factors found to be significantly different between iron replete (IR) and ID/IDA participants were analysed using general linear modelling. ID/IDA participants consumed significantly lower total energy than iron replete (IR) (p = 0.003). Lower energy intake was also associated with higher levels of dietary restraint (p = 0.001). Both HI and NHI were positively associated with SF with HI was found to be a stronger predictor (ß = 0.128, p = 0.009) than NHI (ß = 0.037, p = 0.028). The study demonstrates that intake of both HI and NHI, as well as adequate dietary energy, are associated with normal iron status levels in young women, and that restrained eaters may be at greater risk of low iron status.

Consistency of kinematic and kinetic patterns during a prolonged spell of cricket fast bowling: an exploratory laboratory study.

Due to the high incidence of lumbar spine injury in fast bowlers, international cricket organisations advocate limits on workload for bowlers under 19 years of age in training/matches. The purpose of this study was to determine whether significant changes in either fast bowling technique or movement variability could be detected throughout a 10-over bowling spell that exceeded the recommended limit. Twenty-five junior male fast bowlers bowled at competition pace while three-dimensional kinematic and kinetic data were collected for the leading leg, trunk and bowling arm. Separate analyses for the mean and within-participant standard deviation of each variable were performed using repeated measures factorial analyses of variance and computation of effect sizes. No substantial changes were observed in mean values or variability of any kinematic, kinetic or performance variables, which instead revealed a high degree of consistency in kinematic and kinetic patterns. Therefore, the suggestion that exceeding the workload limit per spell causes technique- and loading-related changes associated with lumbar injury risk is not valid and cannot be used to justify the restriction of bowling workload. For injury prevention, the focus instead should be on the long-term effect of repeated spells and on the fast bowling technique itself.

Iron Deficiency Anemia, Not Iron Deficiency, Is Associated with Reduced Attention in Healthy Young Women.

Women of reproductive age are at increased risk for iron deficiency (ID) and iron deficiency anemia (IDA), with both implicated in decreased cognitive function (CF). Obesity may complicate this association via inflammatory-mediated ferritin elevation. This cross-sectional study examined the association between hematological iron status (iron replete (IR), ID or IDA) and CF in healthy, young (18-35 years) women of normal-weight (NW: BMI 18.5-24.9 kg/m²) or obese-weight (OB: BMI >30 kg/m²). Participants completed a validated, computer-based cognition assessment evaluating impulsivity, attention, information processing, memory and executive function; CF reported as z-scores (mean ± SD). Iron status and CF were compared between groups via ANOVA, with adjustment for potential confounders (BMI, physical activity, C-reactive protein) via ANCOVA. A total of 157 NW and 142 OB women (25.8 ± 5.1 years) participated. Prevalence of ID and IDA were 14% and 6% respectively, with no significant difference between NW and OB groups. Women with IDA scored significantly lower on attention (although within normal range; ±1 z-score), compared to ID (IDA: -0.75 ± 1.89; ID: 0.53 ± 1.37; p = 0.004) but not IR (0.03 ± 1.33, p = 0.21) groups; there were no significant differences between ID and IR groups (p = 0.34). Adjustment for confounders did not significantly alter these results. In conclusion, women with IDA showed significantly reduced attention compared to women with ID.

Sex Differences in Drop Landing: More Apparent in Recreational Surfers Than in Competitive Surfers or Nonsurfers.

We suspected that the observed inconsistency of sex differences in drop-landing motor skills might be due to the confounding factor of prior experience. Thus, in this study, we explored the role of experience in shaping male and female surfboard riders' motor skill kinematics during drop landings while surfboard riding. We recruited 42 participants (21 females and 21 males) from three groups of surfing experience levels (competitive surfers, recreational surfers, and nonsurfers), each equally comprising seven males and seven females. Sagittal plane kinematics and vertical ground reaction force data were collected from all participants during a laboratory-based 60-cm drop-landing task. Knee flexion and ankle dorsiflexion at initial ground contact were greater among male participants, independent of experience level. In both sexes, greater range of motion at these joints was related to greater experience. Recreational female surfers landed in a more upright posture with more extended ankle and knee angles and less ankle dorsiflexion at the end of landing than participants in all other groups. We discuss our results in the context of possible remaining experience differences between male and female participants despite being grouped in the same experience levels in our study, individualized motor patterns that may still achieve similar success, and a need for continued research.