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Jockeys compete in a sport, horseracing, renowned for its physical and psychological demands. Previous research has identified that common mental disorders (CMDs) may be prevalent among this unique population of athletes. The aim of the present study was to further explore the prevalence of CMDs among jockeys and to test for associations with potential risk factors. An anonymous survey was distributed to professional jockey online. Self-report screening tools for four CMDs (psychological distress, depression, generalized anxiety, and adverse alcohol use) were included alongside predictor variables from questionnaires assessing for burnout, career satisfaction, social support, and the contemplation of retirement. Binary logistic regression was used to explore associations between CMDs (present versus not present) and risk factors. Eighty-four professional jockeys completed the questionnaire (response rate = 52%). In total, 79% of jockeys met the threshold for at least one CMD. Prevalence (%) of CMD varied as follows: adverse alcohol (61%), depression (35%), generalized anxiety (27%), and psychological distress (19%). Burnout, career (dis)satisfaction, lower levels of social support, and the contemplation of retirement increased the odds of meeting the criteria for CMDs. The findings indicate that jockeys report CMD symptoms at comparable rates to athletes in other sports. The study was the first to highlight potential risk factors as predictors of CMDs among jockeys, including burnout, career satisfaction, and the current contemplation of retirement. Screening tools for the risk factors demonstrated may, therefore, provide useful in the early identification of CMDs among jockeys. The development of jockey-specific assessment tools, education programmes, and interventions may help better understand and support the mental health of jockeys. [ABSTRACT FROM AUTHOR]

Activity measurement using uniaxial pedometers was validated against behavioral observation using the Children's Activity Rating Scale (CARS) in 30 three- to four-year-old children in a nursery school setting. Correlations were calculated for individual children, whereas the relationship for the total group was investigated using multilevel linear regression. The mean counts for boys and girls for the Digiwalker(TM) were 66.8 (+/- 64.0) and 47.4 (+/- 61.3; p < .01) steps per 3 minutes, respectively, whereas the mean CARS scores for boys and girls were 1.8 (+/- 0.6) and 1.6 (+/- 0.6; p < .01), respectively. Within-child correlations for CARS versus Digiwalker counts ranged from 0.64 to 0.95 with a median value of 0.86; the multilevel analysis provided strong evidence of a relationship between CARS and Digiwalker (all p < .001). Data from the current study show that gender differences in physical levels exist in very young children and support the utility of the Digiwalker pedometer for assessing physical activity in this age group. [ABSTRACT FROM AUTHOR]

Most ballet dancers will suffer at least one injury a year. There are numerous causes of injury in dance, and while many investigators have documented risk factors such as anatomical characteristics, past medical history, menstrual history, dance experience, length of dance training, fatigue, and stress, risk factors related to body characteristics and nutrient intake, levels of conditioning, or physical fitness parameters have only recently received the same amount of attention. The aim of the present study was, therefore, to investigate correlations between ballet injury and body fat percentage, active and passive flexibility, lower limb power, upper body and core endurance, and aerobic capacity. Low levels of aerobic fitness were significantly associated with many of the injuries sustained over a 1 5-week period (r = .590, p = 0.034), and body fat percentage was significantly associated with the length of time a dancer was forced to modify activity due to injury (r = -.614, p = 0.026). This information may be of benefit to dancers, teachers, physical therapists and physicians in dance schools and companies when formulating strategies to prevent injury. [ABSTRACT FROM AUTHOR]

PURPOSE: Evidence suggests that exercise plays an important role in stimulating site-specific bone mineral density (BMD). However, what is less well understood is how these benefits dissipate throughout the body. Hence, the purpose of the present study was to compare the levels of, and the correlation between, BMD recorded at 10 sites in female endurance runners, and to investigate possible determinants responsible for any inter-site differences observed. METHODS: Repeated measures ANOVA was used to compare the BMD between sites and factor analysis was used to describe the pattern of intersite correlations. Allometric ANCOVA was used to identify the primary determinants of bone mass and how these varied between sites. RESULTS: The ANOVA and factor analysis identified systematic differences in BMD between sites, with the greatest BMD being observed in the lower-body sites, in particular the legs. An investigation into the possible mechanisms responsible for these differences revealed 'distances run' (km.wk-1) as a positive, and 'years of training' as a negative determinant of bone mass (P < 0.001). However, the effect of a number of determinants varied between sites (P < 0.05). Specifically, the ANCOVA identified that running further distances resulted in higher bone mass in the arms and legs. In contrast, training for additional years appeared to result in lower bone mass in the arms and lumbar spine. Calcium intake was also found to be positively associated with bone mass in the legs but negatively associated at all other sites. CONCLUSIONS: A combination of running exercise and calcium intake would appear to stimulate the bone mass of women endurance runners at lower-body sites but at the expense of bone mass at upper-body sites. [ABSTRACT FROM AUTHOR]

This study compared peak power estimated using 4 commonly used regression equations with actual peak power derived from force platform data in a group of adolescent basketball players. Twenty-five elite junior male basketball players (age, 16.5 +/- 0.5 years; mass, 74.2 +/- 11.8 kg; height, 181.8 +/- 8.1 cm) volunteered to participate in the study. Actual peak power was determined using a countermovement vertical jump on a force platform. Estimated peak power was determined using countermovement jump height and body mass. All 4 prediction equations were significantly related to actual peak power (all p < 0.01). Repeated-measures analysis of variance indicated significant differences between actual peak power and estimate peak power from all 4 prediction equations (p < 0.001). Bonferroni post hoc tests indicated that estimated peak power was significantly lower than actual peak power for all 4 prediction equations. Ratio limits of agreement for actual peak power and estimated peak power were 8% for the Harman et al. and Sayers squat jump prediction equations, 12% for the Canavan and Vescovi equation, and 6% for the Sayers countermovement jump equation. In all cases peak power was underestimated. [ABSTRACT FROM AUTHOR]

It is important that sources of variation in gas analysis measurements are identified and described in an accurate and informative manner. In this paper, we discussed the potential sources of error, which should be considered in any measurement study on gas analysis systems. We then covered how errors in various terms associated with gas laws propagate to outcome measurements of gas exchange to help quantify the relative importance of sources of error. Finally, we performed a literature survey to explore the statistical methods researchers have employed to arrive at conclusions on the performance characteristics of gas analysis methods. We found examples of excellent practice in the literature, but there were also gaps in the knowledge of error in gas analysis systems. Consequently, we supplied guidelines for future method comparison studies. These guidelines included (i) a sample size of at least 40 participants and the citation of confidence intervals, (ii) a description of the relationships between systematic and random errors and the size of measured value, (iii) the parallel examination of test-retest error within a method comparison study, and (iv) an a priori-made judgement on how much systematic and random error between methods is acceptable for practical applications. We stressed that this judgement should be based on expert-agreed position statements about acceptable error, which unfortunately have yet to be formulated for gas analysis systems. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To report on the contribution walking makes to total weekly physical activity and the relationship between the volume and intensity of walking and leanness in a representative sample of the Northern Ireland population. METHOD: 4563 adults participated in this cross-sectional survey of physical activity behaviour. Self-reported height and weight was used to determine inverse body mass index (iBMI) as a measure of leanness. Data across all domains of physical activity including self-reported volume and intensity of walking (in bouts of 10min or more) were analysed to determine their contribution to leanness using ANCOVA, having controlled for age, gender, socio-economic and smoking status. RESULTS: Over 68% of the participants reported walking >10minutes during the previous week but only 24% report walking at a brisk or fast pace. Time walking at a brisk or fast pace for personal transport was identified as having the strongest positive association with being lean (F(1,4256)=10.45, [beta]=0.051cm(2)kg(-1)min(-1) (SE=0.016),P=0.001). CONCLUSIONS: In addition to increasing the amount of walking and the percentage of people walking regularly, public health messages encouraging an increase in walking pace may be valuable to increase the proportion of the population meeting physical activity guidelines and gaining associated health benefits.Copyright © 2012 by Elsevier Inc. [ABSTRACT FROM AUTHOR]

Scaling, to remove the effects of body size, is an important methodological approach for enabling an equitable comparison of performance differences between individuals who vary in anthropometric characteristics. Many previous studies using scaling in sport have done so based on only one or two anthropometric characteristics, with only one study to date adopting a three-dimensional approach. To apply a three-dimensional allometric model to rowing ergometer performance (REP) in adolescents, and to detect whether key 'scaling' parameters remain stable when scaling REP both before and after a 6-week training intervention. Novel three-dimensional allometric models were used, incorporating body mass, stature and waist circumference (WC) to detect the most appropriate body size dimension(s) and scaling parameters associated with REP before and after a 6-week training intervention. Using this more flexible and sensitive three-dimensional allometry demonstrated that, following 6-weeks of training, there was a change in the ideal body shape associated with REP. Before training, taller, but not heavier, adolescents performed better. After 6-weeks of training, older participants with a greater body mass but smaller WC performed better. Scaling approaches are important for evaluating performance differences between individuals of differing body size. The findings from the current study (using a novel three-dimensional allometry approach) emphasise that relatively subtle changes in individuals' behavioural characteristics, such as changes in their training/fitness status, can result in quite dramatic changes in the body dimension characteristics and scaling parameters deemed to be key for performance in activities such as REP., (© 2024 The Author(s). European Journal of Sport Science published by Wiley‐VCH GmbH on behalf of European College of Sport Science.)

The incidental finding of endometrial thickness (ET) >4 mm in the absence of postmenopausal bleeding (PMB) is a common cause of referring women to secondary care. However, there is lack of consensus amongst gynecologists as regards the management. It is estimated that up to 15 % of endometrial cancers occur in women without PMB. The aim this study was to determine the optimal ET threshold, on trans-vaginal ultrasound scan, that discriminates normal endometrium from endometrial hyperplasia and cancer in this cohort. On using a thorough search strategy, a total 16 studies including 4088 women were deemed eligible. However, the data were not amenable to meta-analysis. There were wide variations in the thresholds reported with potential bias given the retrospective nature of the majority of the studies. Despite contacting authors, we could not obtain the primary data to generate a Receiver Operating Characteristic (ROC) Curve. No linear or curvilinear association was found between ET thresholds and the percentage of women diagnosed with endometrial hyperplasia and cancer using either Pearson's correlation, linear or curvilinear regression, or a simple visual scan/scatter diagram. The result of this study reveals the lack of evidence to inform clinical practice in this area, and there is a need for a well-designed multi-center prospective study., Competing Interests: Declaration of competing interest This review has been presented at the ESGE 32nd Annual Congress 2023 and the abstract only has been published in the official abstract publication of the ESGE Congress named “Facts, Views & Vision”, Journal of the European Society for Gynecological Endoscopy (ESGE) [37]., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Understanding the associations and possible mechanisms between Cardiorespiratory Fitness (CRF) and residential location is an important focus of public health research. This is a cross-sectional study carried out with 2250 students (6-17 years), from southern Brazil. In addition to age, sex, and body size measurements, we also recorded hemoglobin and platelet count measurements using venous blood samples (10 ml). The CRF was measured using the 6-minute run/walk test, with predictors explored via allometry. Results identified a novel and independent association between the hemoglobin-to-platelet count ratio and children's CRF, after controlling for confounders. We also provide evidence of a possible mechanism for this association, having identified reduced measures of hemoglobin and increased platelet counts observed in children living in urban (vs rural) areas. These results suggest the need for more effective public health practices and policies addressing the built enviroment´s health effects in Brazil and potentially other congested ciries.

Purpose: Childhood obesity is a major health concern and physical activity is commonly proposed as an intervention strategy to combat the increasing prevalence of overweight and obesity in young people. The aim of this study was to examine the effect of high-intensity, supervised, rowing ergometer training on maximal and submaximal rowing performance in healthy weight and centrally obese adolescents (12-13 yr)., Methods: Participants were randomized to either 6 wk of supervised rowing ergometry, comprising of 2 sessions per week with each session comprising of 2 × 3-min bouts of high-intensity rowing ergometry ( n = 57), or a control group who continued with their habitual activities ( n = 45). At baseline and follow-up, rowing performance was assessed via a submaximal test and a 3-min maximal test., Results: Six weeks of rowing ergometer training significantly improved maximal exercise performance; total distance rowed in a 3-min maximal effort improved by 19.7 m (2.7%) (time × group, P = 0.018) and produced a significant reduction in perceived effort in response to a set submaximal load (60 W) (time × group, P = 0.040). At baseline total distance rowed during the 3-min maximal test was significantly affected by body mass (main effect of body mass, P = 0.002), whereby a higher body mass was associated with enhanced rowing performance. However, the pattern of change over time was not different between healthy weight and centrally obese adolescents (time × group × waist centile, P = 0.577)., Conclusions: A 6-wk high-intensity rowing ergometry training intervention improved maximal rowing performance. This improvement was similar in healthy weight versus overweight and obese adolescents; yet overall overweight and obese adolescents had superior rowing performance compared to their healthy weight counterparts, suggesting that rowing may be an attractive exercise modality for interventions in overweight and obese young people., (Copyright © 2023 by the American College of Sports Medicine.)

Introduction: The aim of this study was to explore which key somatic features are common to four swim strokes and medley, and specifically to identify which characteristics benefit only specific strokes., Methods: The sample was composed of 130 swimmers (95 males aged 19.5 ± 2.9 years and 35 females aged 18.4 ± 2.8 years). A set of anthropometric variables was used to predict swimming speed in the four swimming strokes and medley., Results: A multiplicative model with allometric body size components was used to identify the demographic and anthropometric predictors of swimming speed. Trunk height and waist circumference were the only variables significantly different among swimming strokes ( p  < 0.05). Associations between swimming speed and arm length were similar in breaststroke and medley, and in freestyle, backstroke and butterfly ( R 2  = 60.9%). The model retained as swimming speed predictors the age 2 , upper body circumference, hand breadth, waist circumference, and subscapular skinfold thickness (these last two had negative associations)., Conclusion: All these predictors were common to all four swim strokes and medley. Arm length was also retained as a significant predictor, but this one varied significantly between the four different swim strokes and medley. These findings highlight the importance of having a "V-shape" trunk, longer upper limbs, and large hands as predictors of swimming performance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Rejman, Nevill, Garrido, Rudnik and Morais.)

The impact of early single sport participation among young people has received much attention, with both sport leaders and pediatricians advocating multi-sport participation at least until early adolescence. In this study we explored the association between family socioeconomic status and level of Irish youth specialization in sport. We relied on data from the Children's Sport Participation and Physical Activity (CSPPA) study, involving a representative sample of 3499 Irish children and adolescents aged 10-15 years. We analyzed data from questions related to the number of sports played, the number of days per week the youth were engaged in sport, and family affluence (as a proxy measure for socioeconomic status). Youth sport specialization before 12 years of age (males 5.7%; females 4.2%) and even between 13-15 years of age (males, 7.8%; females, 5.8%) was uncommon. However, lower levels of specialization were associated with higher socioeconomic status in that more children with high family affluence participated in multiple sports. Careful consideration should be given to whether low socioeconomic status may act as a barrier to participation in multiple sports., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: There has been a decline in children's physical fitness in recent decades. Such concerns are largely based on evidence from North America, Europe, and Asia. The current study describes the secular trend and variation (spread) in the physical fitness scores of young Brazilians from 2005 to 2022., Methods: This study is a repeated, cross-sectional surveillance study (1999-2022). Children and adolescents (n = 65 139; boys = 36 539) participated between 2005 and 2022. In each cohort six physical fitness tests were conducted: (1) 20-m sprint speed (m s -1 ), (2) cardio-respiratory 6-min run test (m min -1 ), (3) abdominal strength test (sit-ups per min), (4) horizontal jump test (cm), (5) the agility test (m s -1 ), and (6) the medicine ball throw test (cm). Means and distributional characteristics of the population were assessed using ANOVA, ANCOVA adopting BMI as the body-size covariate, Levene's test of equality-of-error variances, and Box and whisker plots., Results: ANOVAs and ANCOVA's identified significant declines in physical fitness over time/year in 5 of the 6 physical fitness variables (e.g., 20-m sprint speed slope B = -0.018 (m s -1  y -1 ); 95% CI -0.019 to -0.017; p < 0.001), the only exception being the medicine ball throw test (cm). The Levene's test of equality-of-error variances also identified a systematic increase in the variances/standard deviations over time/years., Conclusions: Results provide powerful evidence that children and adolescents' physical fitness is declining, a trend that is also diverging asymmetrically, becoming more extreme in more recent years. The "fit" appear to be getting fitter, but the fitness of the "less-fit" appears to be declining further. These results have important implications for sports medicine and government policy makers., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Abstract: Sammoud, S, Negra, Y, Chaabene, H, Bouguezzi, R, Attia, A, Granacher, U, Younes, H, and Nevill, AM. Key anthropometric variables associated with front-crawl swimming performance in youth swimmers: an allometric approach. J Strength Cond Res 37(6): 1259-1263, 2023-This study aimed to establish key anthropometric characteristics (e.g., optimal body height, limb-segment length, and girth/breadth ratios) related to 100-m front-crawl performance in young swimmers. In total, 74 swimmers (boys [ n = 41; age: 18.1 ± 3.5 years]; girls [ n = 33; age: 15.9 ± 3.1 years]) participated in this study. We adopted a multiplicative allometric log-linear regression model to identify key anthropometric characteristics associated with 100-m front-crawl swimming performance. The main outcomes indicated that length ratio = ([height/leg length]), foot length and ankle girth, biacromial breadth, and % of body fat were associated with 100-m front-crawl mean swimming speed performance. These findings highlight the importance of assessing anthropometric characteristics in young front-crawl swimmers for talent identification and development., (Copyright © 2020 National Strength and Conditioning Association.)

The aims of this study were to: (1) analyze and compare the stroke kinematics between junior and senior elite male swimmers in every section of the race during the 50-m freestyle event, and; (2) identify stroke frequency (SF)-stroke length (SL) combinations on swim speed independently for junior and senior swimmers in each section of the 50-m freestyle event. Eighty-six junior swimmers (2019) and 95 seniors (2021) competing in the 50-m long course meter LEN Championships were analyzed. The t-test independent samples (p ≤ 0.05) were used to compare juniors and seniors. The SF and SL combinations on swim speed were explored using three-way ANOVAs. Senior swimmers were significantly faster in the 50-m race than juniors (p < 0.001). Speed presented the largest significant difference (p < 0.001) in section S0-15 m (start until the 15 th meter mark) being seniors fastest. Both junior and senior swimmers revealed a significant categorization (p < 0.001) by stroke length and stroke frequency in each race section. It was possible to model several SF-SL combinations for seniors and juniors in each section. The fastest swim speed in each section, for seniors and juniors independently, was achieved by a SF-SL combination that may not be the fastest SF or the longest SL. Coaches and swimmers must be aware that despite the 50-m event being an all-out bout, several SF-SL combinations were observed (independently for juniors and seniors), and they differ between race sections., (© Journal of Sports Science and Medicine.)

Objectives: To a) demonstrate that adopting 'at risk' waist-to-height ratio (WHTR) cut-off points, recently approved by National Institute for Health and Care Excellence (NICE) and the United States Department of Defense (USDoD), will unfairly penalize shorter individuals and will be too lenient for taller individuals, b) to confirm that waist circumference (WC) of a sample of US service personnel, scales to approximately height 0.5 , supporting the notion that WC, to be independent of height (HT), should be normalized using WC.HT -0.5 (WHT•5R), and c) to identify the WHT•5R cut-off points that will reduce or eliminate this unwanted bias., Subjects/methods: We employed a three independent cross-sectional sample design. All n = 58,742 participants underwent anthropometric assessment of body mass, stature and waist circumference., Results: The allometric power-law model WC=a.HT^b for US service personnel identified the height exponent to be b= 0.418 (95 % CI 0.251-0.585), confirming that the simple body-shape index for WC to be independent of HT, should be WC.HT -0.5 . Chi-square tests of independence and for linear trend confirmed that by adopting WHTR cut-off point, shorter individuals (both service personnel and non-service participants) will be over penalized (classified as being 'at risk'). New WC independent-of-height ratio cut-off points were found to resolve this problem., Conclusions: Adopting WHTR cut-off thresholds (either 0.5 or 0.55) will lead to shorter adults being unfairly classified as being 'at risk' in terms of their central adiposity and general health status. Adopting new WHT•5R cut-off point thresholds were found to greatly reduce or eliminate this bias., Competing Interests: Competing interests The authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The objective of this study was to holistically examine the impact of long-haul transmeridian travel (LHTT) on perceptual, mood, sleep and physiological markers in Olympic team support staff travelling to Japan for the 2020 Summer Olympic Games. An observational descriptive study design was used. Nine support staff members of the Irish Olympic team (2 M/7 F; age 34.3 ± 8.3 y (mean ±SD)) embarked on a long-haul (LH) eastward flight across eight time-zones from Ireland to Japan (approx. 24 h total travel time), to work at the Irish Team's 2020 Summer pre-Olympic Games camp, postponed to July 2021 due to Covid-19 pandemic. Perceived jet lag and travel fatigue symptoms, mood states and salivary markers for circadian rhythm and stress were assessed in the morning and evening during the week prior to travel as baseline (BL) measures and on days 1 to 8 (C1-C8) and day 15 (C15) post-travel. Night-time sleep (duration and quality) was monitored via actigraphy monitors and self-report sleep diaries. Participants perceived themselves to be significantly jet lagged for six days post-travel (p < .05). Morning sCort decreased by 66% on C1 and remained significantly lower than BL until C6 (p ≤ .03). On arrival participants perceived sleep to be worse than BL on arrival (C1, C2, C4, C5; p ≤ .04), with significantly shorter sleep duration (C2, C3, C6; p ≤ .01) and lower sleep efficiency (C2, C6; p ≤ .04) recorded by actigraphy, all normalizing by C7. Negative changes in mood states were evident in the evening time following LHTT, with significant elevations in confusion (C2, C3, p ≤ .02), fatigue (C2, C3; p ≤ .03) and depression (C3, C7; p < .05) and reduction in vigour (C2, C6, C7; p < .05). Following LHTT in an eastward direction across eight time-zones, it took seven days for perceived jet lag, physiological markers for circadian rhythm and sleep to normalize in Olympic team support staff. Despite alleviation of jet lag and fatigue and return of sleep to normal by C15, vigor remained low, indicating a "submerged" mood profile in these Olympic team support staff. These findings highlight the need to put strategies in place before and after LHTT for the Olympic Games to assist Olympic team support staff to maximize sleep, minimize stress and assist with expediating recovery from jet lag and travel fatigue, allowing them to perform optimally in supporting Olympic athletes in their final preparations for the Games.

Abstract: Tiernan, C, Comyns, T, Lyons, M, Nevill, AM, and Warrington, G. The association between training load indices and injuries in elite soccer players. J Strength Cond Res 36(11): 3143-3150, 2022-To investigate the association between contact injuries, noncontact injuries, and training load indices, across different lag periods in elite soccer players. Internal load (session rate of perceived exertion) was collected from 15 elite soccer players over 1 season (40-weeks). Acute (7 days), chronic (28 days), acute:chronic workload ratio (ACWR) (uncoupled), exponentially weighted moving averages (EWMA) ACWR, and 2-, 3-, and 4-week cumulative load were calculated on a rolling weekly basis. Multilevel logistic regression was used to analyze the associations between contact, noncontact injuries, and training load indices, across different lag periods (5 and 7 days). A player was at a significantly higher risk of a noncontact injury 5 days later, if week-to-week acute load changes increased (odds ratio [OR] = 1.97). An increase in EWMA ACWR was associated with an increased risk of both a contact (OR = 1.30) and noncontact injury (OR = 1.35), 5 days later. An increase in 2-week cumulative load (OR = 1.77) was associated with an increased risk of a contact injury 7 days later and 3-week cumulative load (OR = 1.55) 5 days later. These findings suggest that to reduce the potential risk of a noncontact injury, training load should be gradually increased, avoiding an increase in week-to-week acute load change (≥9%) or EWMA ACWR (>1.20). Findings indicated that EWMA ACWR may be a more sensitive measure for detecting a player at a higher risk of an injury than ACWR. Furthermore, a high 2- and 3-week cumulative load was associated with an increased risk of a contact injury, which may indicate accumulated fatigue. Practitioners must note that this study investigated associations with injury risk and not injury prediction., (Copyright © 2020 National Strength and Conditioning Association.)

Despite a clear distinction between aerobic and muscle strengthening (MS) components in the physical activity guidelines, public health surveillance has largely focused only on aerobic components, limiting the reach of epidemiological research on the physical activity guidelines. Hence, this study investigated the association between adherence to both components (i.e. aerobic and muscle-strengthening) of the World Health Organization's physical activity guidelines and mental health among the college student population. A cross-sectional study was conducted among a nationally representative sample of Irish college students (7088 participants, M age: 23.17 years; 50.9% female). Participants were categorized as meeting both components of the guidelines (n = 41%), only the aerobic component (n = 25.3%) or the MS component (n = 7.3%), and neither (n = 26.4%). Group membership effects on mental health was determined through mixed univariate ANOVAs, with a Bonferroni correction for post hoc analyses to assess multiple comparisons. Results revealed that meeting both components of the guidelines was significantly (all p < 0.01) associated with greater self-reported happiness, body image and general health, and less mental ill-being, relative to all other respective groupings. Meeting aerobic or MS components in isolation was significantly (p < 0.05) associated with better happiness, general health and body image compared to not meeting either component. To conclude, 59% of the college-aged population are insufficiently active, and adherence to both guideline components is positively associated with mental health. Co-produced, evidence-based, physical activity interventions are needed in students and could contribute to mental health promotion., (© Crown copyright 2022.)

Background: Healthcare service provision in inflammatory bowel disease (IBD) is often designed to meet targets set by healthcare providers rather than those of patients. It is unclear whether this meets the needs of patients, as assessed by patients themselves., Aims: To assess patients' experience of IBD and the healthcare they received, aiming to identify factors in IBD healthcare provision associated with perceived high-quality care., Methods: Using the 2019 IBD standards as a framework, a national benchmarking tool for quality assessment in IBD was developed by IBD UK, comprising a patient survey and service self-assessment., Results: 134 IBD services and 9757 patients responded. Perceived quality of care was lowest in young adults and increased with age, was higher in males and those >2 years since diagnosis. No hospital services met all the national IBD standards for recommended workforce numbers. Key metrics associated with patient-reported high- quality care were: identification as a tertiary centre, patient information availability, shared decision- making, rapid response to contact for advice, access to urgent review, joint medical/surgical clinics, and access to research (all p < 0.001). Higher numbers of IBD nurse specialists in a service was strongly associated with patients receiving regular reviews and having confidence in self-management and reporting high- quality care., Conclusions: This extensive patient and healthcare provider survey emphasises the importance of aspects of care less often measured by clinicians, such as communication, shared decision- making and provision of information. It demonstrates that IBD nurse specialists are crucial to meeting the needs of people living with IBD., (© 2022 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.)

Background: Few studies have investigated the optimal anthropometric index associated with potential cardio-metabolic risk. Using direct measures of standing height, body mass, and waist circumference, we sought to identify the optimal index for detecting cardio-metabolic risk associated with diabetes and hypertension in a nationally representative sample of US adults., Methods: Complete (non-missing) cross-sectional data from 8375 US adults aged 18-80+ years were obtained from the 2015-16 and 2017-March 2020 (pre-pandemic) cycles of the National Health and Nutrition Examination Survey. The cardio-metabolic risk was identified using blood pressure and glycohemoglobin (A1c). Allometric models were used to identify the optimal anthropometric indices associated with cardio-metabolic risk. Receiver operating characteristics curves were used to verify the discriminatory ability of the identified index in comparison with other anthropometric measures., Results: The optimal anthropometric index associated with cardio-metabolic risk was waist circumference divided by body mass to the power of 0.333 (WC/M 0.333 ). The ability for this new index to discriminate those with diabetes (area under the ROC curve: 0.73 [95%CI: 0.71-0.74]) and hypertension (area under the curve: 0.70 [95%CI: 0.69-0.72]) was superior to all other anthropometric measure/indices investigated in this study (body mass index, waist circumference, waist-to-height ratio, and waist/height 0.5 )., Conclusions: We identified WC/M 0.333 as the optimal anthropometric index for identifying US adults with hypertension and diabetes. Instead of using body mass index (kg/m 2 ), we recommend using WC/M 0.333 in clinical and public health practice to better identify US adults at potential cardio-metabolic risk associated with hypertension and diabetes., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

The National Institute for Clinical Excellence (NICE) has just released its latest guidelines to assess and predict health risk, such as type 2 diabetes, hypertension or cardiovascular disease. Their latest advice is "Keep the size of your waist to less than half of your height". We believe this advice is flawed and will seriously and unfairly penalize shorter people and lull taller people into a false sense of security. In this short communication, we provide this evidence. We consider this a serious oversight by NICE and feel strongly that this evidence needs to be made available in the public domain., (Copyright © 2022 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.)

Background and Aims: There is growing evidence that Body Mass Index (BMI) is unfit for purpose. Waist circumference (WC) indices appear to be the preferred alternative, although it is not clear which WC index is optimal at predicting cardio-metabolic risk (CMR) and associated health outcomes., Methods and Results: We obtained a stratified random probability sample of 53,390 participants from the Health Survey for England (HSE), 2008-2018. The four available CMR factors were; high-density lipoproteins (HDL) cholesterol, glycated haemoglobin (HbA1c), systolic (SBP) and diastolic blood pressure (DBP). Strength of association between the four cardio-metabolic risk factors and competing anthropometric indicators of weight status [BMI, Waist-to-height ratio (WHTR), unadjusted WC, and a new WC index independent of height, WHT·5R = WC/height 0.5 ] was assessed separately, using simple correlations and ANCOVAs, and together (combined) using MANCOVA, controlling for age, sex and ethnicity. Centile curves for the new index WHT·5R = WC/height 0.5 were also provided., Conclusions: Waist-circumference indices were superior to BMI when explaining/predicting our CMR factors, before and after controlling for age, sex and ethnicity. No single WC index was consistently superior. Results suggest that WHTR is the strongest predictor of HbA1c, confirming that shorter individuals are at great risk of diabetes. The most appropriate WC index associated with blood pressure was WHT·5R for DBP, or unadjusted WC for SBP. Given HDL cholesterol is independent of height, the best predictor of HDL was WHT.5R. Clearly, "no one size fits all!". MANCOVA identified WHT·5R to be the best single WC index associated with a composite of all four CMR factors., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

This study aimed to develop the optimal allometric body size/shape and a biological maturity model that predicted the change of direction (CoD) mean speed performance in youth male soccer players. One-hundred and fifteen youth soccer players (age: 12.4 [1.3] y) participated in this study. The 505 test was used to assess CoD mean speed performance. Anthropometric measurements comprised body height (cm), sitting height (cm), body mass (kg), fat mass (kg), lower limb length (cm), thigh length (cm), leg length (cm), foot length (cm), thigh girth (cm), and calf girth (cm). The maturity status was determined based on the maturity offset method. To identify size/shape and maturity characteristics associated with CoD speed performance, we computed a multiplicative allometric log-linear regression model, which was refined using backward elimination. The multiplicative allometric model exploring the association between 505 CoD mean speed performance and the different anthropometric characteristics in youth soccer players estimated that fat mass (P < .001), sitting height (P = .02), and maturity offset (P = .004) are the key predictors. More specifically, youths who are more mature and have a lower fat mass and a shorter trunk length, are likely to achieve a better CoD mean speed performance. These findings highlight the relevance of considering anthropometric and maturity characteristics in youth soccer players to support talent identification.

Introduction: This study aimed to: 1) determine swimming velocity based on a set of anthropometric, kinematic, and kinetic variables, and; 2) understand the stroke frequency (SF)-stroke length (SL) combinations associated with swimming velocity and propulsion in young sprint swimmers. Methods: 38 swimmers (22 males: 15.92 ± 0.75 years; 16 females: 14.99 ± 1.06 years) participated and underwent anthropometric, kinematic, and kinetic variables assessment. Exploratory associations between SL and SF on swimming velocity were explored using two two-way ANOVA (independent for males and females). Swimming velocity was determined using multilevel modeling. Results: The prediction of swimming velocity revealed a significant sex effect. Height, underwater stroke time, and mean propulsion of the dominant limb were predictors of swimming velocity. For both sexes, swimming velocity suggested that SL presented a significant variation (males: F = 8.20, p < 0.001, η 2 = 0.40; females: F = 18.23, p < 0.001, η 2 = 0.39), as well as SF (males: F = 38.20, p < 0.001, η 2 = 0.47; females: F = 83.04, p < 0.001, η 2 = 0.51). The interaction between SL and SF was significant for females (F = 8.00, p = 0.001, η 2 = 0.05), but not for males (F = 1.60, p = 0.172, η 2 = 0.04). The optimal SF-SL combination suggested a SF of 0.80 Hz and a SL of 2.20 m (swimming velocity: 1.75 m s -1 ), and a SF of 0.80 Hz and a SL of 1.90 m (swimming velocity: 1.56 m s -1 ) for males and females, respectively. The propulsion in both sexes showed the same trend in SL, but not in SF (i.e., non-significant variation). Also, a non-significant interaction between SL and SF was observed (males: F = 0.77, p = 0.601, η 2 = 0.05; females: F = 1.48, p = 0.242, η 2 = 0.05). Conclusion: Swimming velocity was predicted by an interaction of anthropometrics, kinematics, and kinetics. Faster velocities in young sprinters of both sexes were achieved by an optimal combination of SF-SL. The same trend was shown by the propulsion data. The highest propulsion was not necessarily associated with higher velocity achievement., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer MCM declared a shared affiliation with the author DM to the handling editor at the time of review., (Copyright © 2022 Morais, Barbosa, Nevill, Cobley and Marinho.)

Children recover faster than adults in repeated sprints, but it is unclear if their aerobic responses differ., Purpose: This study tested the hypothesis that aerobic response (VO 2 ) during repeated sprints is greater in preadolescent boys than in men. Further, this study compared normalization with conventional ratio-scaling and scaling with the use of body mass (BM) as a covariate., Methods: Nine boys (age: 11.8 ± 0.6 years, swimmers) and 11 men (age: 21.7 ± 0.6 years, recreational athletes) performed 10 maximal 6-s cycling sprints separated by 24-s of passive recovery, against two loads (optimum and 50% of optimum). Oxygen uptake (VO 2 ) was measured continuously., Results: Men's mean power output (MPO) was greater than boys in each sprint, both in absolute (unscaled) values (  p  < 0.05) and when adjusted for lean leg volume (  p  < 0.05). Children had lower absolute VO 2 (  p  < 0.05) than men, but when it was adjusted for BM or power-output, VO 2 was comparable between men and boys. Thus, most of the difference in VO 2 between men and boys was due to body size and power-output differences., Conclusion: Our results suggest that men and boys have similar VO 2 during repeated sprints when appropriately adjusted to body mass or power output. Results highlight the importance of using appropriate scaling methods to compare adults' and children's aerobic responses to high-intensity exercise., Competing Interests: The reviewer AZ declared a past collaboration with one of the authors GB to the handling editor. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Theos, Bogdanis, Jansson, Nevill, Papaspyrou and Maridaki.)

Introduction: Handgrip strength (HGS) is an important indicator of health. Because HGS is strongly associated with body size, most investigators normalize HGS for some measure of body size as a more sensitive indicator of strength within a population. We aimed to 1) identify the optimal body size dimension to remove (normalize) HGS for differences in body size among adults and 2) generate norm-referenced centiles for HGS using the identified body size dimension., Methods: Data were from the National Health and Nutrition Examination Survey, a representative sample of the US noninstitutionalized civilian population. Exclusions resulted in a final sample of 8690 adults 20 yr and older. HGS was measured using handheld dynamometry. Body size dimensions included body mass, height, and waist circumference. The most appropriate dimension(s) associated with HGS is identified using allometry. We fitted centile curves for normalized HGS using the generalized additive model for location, scale, and shape., Results: Findings suggest that neither body mass nor body mass index is appropriate to normalize HGS. Incorporating all three body size dimensions of body mass, height, and waist circumference, or the reduced subsets of body mass and height, or height alone, suggests that the most appropriate normalizing (body size) dimension associated with HGS should be a cross-sectional or surface area measure of an individual's body size (i.e., L2, where L is a linear dimension of body size). Given that height was also identified as the signally best body size dimension associated with HGS, we recommend HGS be normalized by height2 (i.e., HGS/HT2). Centile curves for HGS/HT2 by age group and gender were therefore provided., Conclusions: Scaling adult HGS by height2 may help normalize strength for population-based research., (Copyright © 2021 by the American College of Sports Medicine.)

Dance injury research has mainly focused on ballet and modern dance with little data on musical theatre dancers. The purpose was to assess the incidence and severity of injuries in a musical theatre dance college over a 5-year period; 198 pre-professional musical theatre dancers (3 cohorts on a 3-year training course) volunteered for the study; 21 students left the course over the study period. Injury aetiology data were collected by an in-house physiotherapy team. Differences between academic year and sex were analysed using a Poisson distribution model; significant difference was set at p≤0.05. In total, 913 injuries were recorded, and more injuries occurred in academic year 1 than year 2 and 3. Overall injury incidence was 1.46 injuries per 1000 hours (95% CI 1.34, 1.56); incidence significantly decreased between year 1, 2 and 3 (p<0.05). There was no significant sex difference for incidence or severity. Most injuries were classified as overuse (71% female, 67% male). Pre-professional musical theatre dancers report a high proportion of lower limb and overuse injuries comparable to other dance genres. Unlike other studies on pre-professional dancers, injury incidence and severity decreased with academic year, even though workload increased across the course., Competing Interests: The authors have no financial affiliation (including research funding) or involvement with any commercial organisation that has a direct financial interest in any matter included in this manuscript. We do not have any other conflict of interest (i.e. personal associations or involvement as a director, officer, or expert witness)., (Thieme. All rights reserved.)

Purpose: Recently, doubts have been raised concerning the validity of the 20-m shuttle run test (20mSRT) to predict cardiorespiratory fitness (CRF) in youth. Despite these doubts, authors continue to provide powerful evidence that CRF can be predicted reliably using the 20mSRT albeit using contrasting models. Therefore, we aimed to compare a new linear model with an alternative allometric model to predict CRF (peak oxygen uptake, V˙O2peak) using the 20mSRT., Methods: The study included 148 adolescents (43% girls) age 13.37 ± 1.84 yr. Adolescents were randomly assigned to validation (n = 91) and cross-validation (n = 57) groups. V˙O2peak was measured using a gas analyzer in both maximal exercise tests in the laboratory and the 20mSRT. Multiple linear regression methods were applied to develop the linear models using the 20mSRT (laps), body mass index, and body fat percentage. Alternative allometric models were also proposed/fitted using the 20mSRT (laps), height, and body mass., Results: The criterion validity values of both the linear and the allomeric models were found to be acceptable, with R2 = 82.5% and 82.7% respectively, providing reassuring evidence that the 20mSRT can be used with confidence to predict CRF. However, the allometric model identified a height-to-mass ratio, not dissimilar to the inverse body mass index (known to be a measure of leanness), to be associated with CRF. The allometric model also revealed that the rise in energy cost (V˙O2peak) with increasing laps was exponential. This will more accurately reflect the nonlinear rise in energy demand of shuttle running as the test progresses to exhaustion., Conclusions: These observations provided powerful evidence that allometric models are more than satisfactory in terms of both criterion and construct validity when predicting CRF (V˙O2peak) using the 20mSRT., (Copyright © 2021 by the American College of Sports Medicine.)

Abstract Purpose: Previous research has captured point estimates for population means of somatic variables associated with swimming speed across strokes, but have not determined if predictors of swimming speed operate the same at the upper tails of the distribution ( τ  = 0.9) as they do at the median levels ( τ  = 0.5) and lower levels ( τ  = 0.1). Method: Three hundred sixty-three competitive-level swimmers (male [ n  = 202]; female [ n  = 161]) participated in the study. To identify key somatic variables associated with 100-m swimming across and between strokes controlling for age, we used a Bayesian allometric quantile regression model, refined using Bayes Factors and Leave-one-out cross validation. Results: High probabilities (>99%) were found for arm-span, seated-height and shoulder-breadth being the strongest somatic predictors across strokes. For individual strokes, Bayesian quantile regression demonstrated that the relative importance of predictors differs across quantiles. For swimmers in the 0.9 quartile, shoulder-breadth is a more important than height for front-crawl, wide shoulders are important for breaststroke swimmers but can be detrimental when combined with narrow hips, seated-height and hip-width are important for backstroke swimming speed, and calf girth for butterfly. Conclusion: These results highlight the importance of considering key somatic variables for talent identification in swimming and ensure young swimmers focus on strokes compatible with their somatic structure. The most important new insight is that predictors differ for the best swimmers compared to average or poorer swimmers. This has implications beyond swimming, pointing to the importance of considering the upper tails of distributions in performance and talent identification contexts.

Identifying vulnerable groups and/or individuals' cardiorespiratory fitness (CRF) is an important challenge for clinicians/researchers alike. To quantify CRF accurately, the assessment of several variables is now standard practice including maximal oxygen uptake ( V ' CO 2 ) and ventilatory efficiency, the latter assessed using the minute ventilation/carbon dioxide production ( V ' E / V ' CO 2 ) slope. Recently, reference values (centiles) for V ' E / V ' CO 2 slopes for males and females aged 20 to 80 have been published, using cardiopulmonary exercise testing (CPX) data (treadmill protocol) from the Fitness Registry and the Importance of Exercise National Database (FRIEND Registry). In the current observational study we provide centile curves for the FRIEND Registry V ' E / V ' CO 2 slopes, fitted using the generalised additive model for location, scale and shape (GAMLSS), to provide individuals with a more precise estimate of where their V ' E / V ' CO 2 slopes fall within the population. We also confirm that by adopting allometric models (incorporating a log transformation), the resulting ANCOVAs provided more normal and homoscedastic residuals, with superior goodness-of-fit using the Akaike information criterion (AIC)=14 671 (compared with traditional ANCOVA's AIC=15 008) that confirms allometric models are vastly superior to traditional ANCOVA models. In conclusion, providing sex-by-age centile curves rather than referring to reference tables for ventilatory efficiency ( V ' E / V ' CO 2 slopes) will provide more accurate estimates of where an individual's particular V ' E / V ' CO 2 slope falls within the population. Also, by adopting allometric models researchers are more likely to identify real and valid inferences when analysing population/group differences in V ' E / V ' CO 2 slopes., Competing Interests: Conflict of interest: A.M. Nevill has nothing to disclose. Conflict of interest: J. Myers has nothing to disclose. Conflict of interest: L.A. Kaminsky has nothing to disclose. Conflict of interest: R. Arena has nothing to disclose. Conflict of interest: T.D. Myers has nothing to disclose., (Copyright ©The authors 2021.)

Body mass index (BMI) is thought to reflect excess adiposity in both youth and adults alike. However, the association between BMI and fatness varies, especially as children grow into adults. Thus, the present study sought to address this issue by characterizing how BMI reflects age and sex differences in body fatness in 7-16-year-old children., Methods: This cross-sectional study was conducted with 2150 children and adolescents, aged 7 to 16 years from the city of Santa Cruz do Sul, Brazil. BMI (kg/m 2 ), and percentage body fat, using tricipital and subscapular folds, were assessed. For statistical analysis, ANOVA and ANCOVA were used., Results: When considered in isolation, there was no significant interaction in the age-by-sex differences in BMI ( p = 0.69). However, when we controlled for percent body fatness, the analysis revealed considerable age-by-sex differences in BMI ( p < 0.001)., Conclusion: For the same body fat (%), there are no differences in BMI in children <10 years.