Validity and reliability of the International fItness scale (IFIS) in preschool children.

Objectives: Examine the validity and reliability of parent-reported International FItness Scale (IFIS) in preschoolers. Method: A cross-sectional study of 3051 Spanish preschoolers (3-5 years). Fitness was measured by PREFIT battery and reported by parents using an adapted version of the IFIS. Waist circumference was evaluated, and the waist-to-height ratio (WHtR) was calculated. Seventy-six parents of randomly selected schoolchildren completed the IFIS twice for a reliability assessment. Results: ANCOVA, adjusted for sex, age and WHtR, showed that preschoolers who were scored by their parents as having average-to-very good fitness had better levels of measured physical fitness than those preschoolers who were classified as having "very poor/poor" fitness levels (18.1laps to 22.1laps vs 15.6laps for cardiorespiratory fitness; 6.6 kg to 7.5 kg vs 5.3 kg for muscular fitness-handgrip-; 71.7 cm to 76.4 cm vs 62.0 cm for muscular fitness-standing long jump-; 17.2s to 16.2s vs 18.2s for speed/agility; and 11.2s to 15.6s vs 8.7s for balance; p < 0.001). The weighted kappa for concordance between parent-reported fitness levels and objective assessment was poor (κ ≤ 0.18 for all fitness measures). Overall, the mean values of the abdominal adiposity indicators were significantly lower in high-level fitness categories reported by parents than in low-level fitness categories (p < 0.05). The test-retest reliability ranged from 0.46 to 0.62. Conclusions: The reliability of the parent-reported IFIS are acceptable, but the concordance between parents reported and objectively measures fitness levels is poor, suggesting that parents' responses may not be able to correctly classify preschoolers according to their fitness level.HighlightsThe convergent validity and reliability (test-retest) values of the IFIS parent scale are moderately acceptable for assessing physical fitness in children aged 3-5 years.However, the results of concordance show that criterion validity is poor suggesting that parents' responses may not be able to correctly classify preschoolers according to their fitness level.Considering that the fitness level at these ages is fairly homogeneous, it seems difficult for parents to discriminate between the fitness levels of their children. Therefore, it seems necessary to recalibrate the scale in future work.

Effects of bariatric surgery on cardiorespiratory fitness: A systematic review and meta-analysis.

Although bariatric surgery (BS) is recognized as an effective strategy for body weight loss, its impact on cardiorespiratory fitness (CRF) is still unclear. We aimed to examine postoperative changes in CRF (VO2max/peak ) and its relationship with weight loss among adults undergoing BS. We systematically searched the WoS, PubMed, MEDLINE, and Scopus databases. Observational and intervention studies were selected reporting the presurgery and postsurgery CRF, measured by breath-by-breath VO2 or its estimation. Eleven articles (312 patients) revealed that BS leads to a reduction in absolute VO2max/peak in the short term (effect size, ES = -0.539; 95%CI = -0.708, -0.369; p < 0.001), and those patients who suffered a more significant decrease in BMI after BS also had a greater loss of absolute VO2max/peak . However, VO2max/peak relative to body weight increased after surgery (ES = 0.658; 95%CI = 0.473, 0.842; p < 0.001). An insufficient number of studies were found investigating medium and long-term changes in CRF after BS. This study provides moderate-quality evidence that the weight loss induced by BS can reduce CRF in the short term, which represents a therapeutic target to optimize BS outcomes. More high-quality studies are needed to evaluate the impact of BS on VO2max/peak in the short, medium, and long term including normalized values for fat-free mass.

Supervised Exercise Immediately After Bariatric Surgery: the Study Protocol of the EFIBAR Randomized Controlled Trial.

BACKGROUND: Previous studies have investigated weight loss caused by exercise following bariatric surgery. However, in most cases, the training program is poorly reported; the exercise type, volume, and intensity are briefly mentioned; and the sample size, selection criteria, and follow-up time vary greatly across studies. PURPOSE: The EFIBAR study aims to investigate over 1 year the effects of a 16-week supervised exercise program, initiated immediately after bariatric surgery, on weight loss (primary outcome), body composition, cardiometabolic risk, physical fitness, and quality of life in patients with severe/extreme obesity. MATERIAL AND METHODS: The EFIBAR study is a parallel-group, superiority, randomized controlled trial (RCT), comprising 80 surgery patients. Half of the participants, randomly selected, perform a 16-week supervised exercise program, including both strength and aerobic training, starting immediately after the surgery (7-14 days). For each participant, all primary and secondary outcomes are measured at three different time points: (i) before the surgery, (ii) after the intervention (≈4 months), and (iii) 1 year after the surgery. CONCLUSION: The EFIBAR study will provide new insights into the multidimensional benefits of exercise in adults with severe/extreme obesity following bariatric surgery. TRIAL REGISTRATION: EFIBAR randomized controlled trial was prospectively registered at Clinicaltrials.gov (NCT03497546) on April 13, 2018.

Impact of exercise training after bariatric surgery on cardiometabolic risk factors: a systematic review and meta-analysis of controlled trials.

The purpose of this systematic review was to provide updated evidence synthesis of the effectiveness of exercise training in patients with obesity undergoing bariatric surgery to improve cardio-metabolic risk. We systematically searched the MEDLINE, EMBASE, Scopus, Cochrane, and Web of Science databases. The studies selected were those in which an exercise-based intervention was performed after bariatric surgery, a control group was present, and at least one of the following outcomes was investigated: VO2max or VO2peak, resting heart rate (RHR), blood pressure, lipid profile, glucose, and insulin. The study quality was assessed using the PEDro scale and the data were meta-analyzed with a random effects model, comparing control groups to intervention groups using standardized measurements. Twenty articles were included in the systematic review and fourteen (70%) in the meta-analysis. Significant differences were observed between the control and intervention groups (always in favor of exercise) for absolute VO2max / VO2peak (ES = 0.317; 95% CI = 0.065, 0.569; p = 0.014), VO2max / peak relative to body weight (ES = 0.673; 95% CI = 0.287, 1.060; p = 0.001), HDL cholesterol (ES = 0.22; 95% CI = 0.009, 0.430; p = 0.041) and RHR (ES = -0.438; 95% CI = -0.753, -0.022; p = 0.007). No effects were observed for either systolic or diastolic blood pressure. Exercise training for patients undergoing bariatric surgery appears to be effective in improving absolute and relative VO2max / VO2peak, HDL cholesterol and reducing the RHR. More intervention studies using (better) exercise interventions are needed before discarding their effects on other cardiometabolic risk factors. This systematic review and meta-analysis has been registered in Prospero (CRD42020153398).

Ideal cardiovascular health in women with systemic lupus erythematosus: Association with arterial stiffness, inflammation, and fitness.

BACKGROUND: Systemic Lupus Erythematosus (SLE) is closely related to cardiovascular morbidity and mortality. We aimed to examine the association of ideal cardiovascular health (ICH) with arterial stiffness, inflammation, and physical fitness in women with SLE. METHODS: This cross-sectional study included 76 women with SLE (age 43.4±13.8 years old). Ideal levels of 7 health metrics (smoking, body mass index, physical activity, healthy diet, blood pressure, cholesterol, and glucose) were used to define the ICH score (ranging from 0 to 7 ideal metrics) and the ICH status ( defined as presenting ≥4 ideal metrics). Arterial stiffness was measured through pulse wave velocity (PWV) and inflammation through serum high sensitivity C-reactive protein (hs-CRP). Cardiorespiratory fitness (CRF) was measured by 6-min walk test (6MWT), and Siconolfi step test and muscular strength by handgrip strength and 30-s chair stand, and range of motion (ROM) by the back-scratch test. RESULTS: Higher ICH score was associated with lower PWV (ß = -0.122, p = 0.002), lower hs-CRP (ß = -0.234, p = 0.056), higher CRF [6MWT (ß = 0.263, p = 0.041); Siconolfi step test (ß = 0.330, p < 0.001)], higher ROM (ß = 0.278, p = 0.013) and higher relative handgrip strength (ß = 0.248, p = 0.024). Women with ICH status presented lower PWV (mean difference 0.40 m/s, 95% CI 0.17 to 0.63, p = 0.001), and higher CRF [assessed by 6MWT (mean difference 43.9 m, 95% CI 5.0 to 82.7, p = 0.028)], than women with non-ICH status. Sensitivity analyses using ICH score ranging 0-14 and considering ICH status with ≥5 metrics revealed consistent results. CONCLUSION: ICH is associated with lower arterial stiffness, lower inflammation, and higher fitness in women with SLE. Although these results extend current knowledge about the potential role of ICH for primordial prevention of CVD in SLE, they are yet to be confirmed in future prospective research .

Heart Rate Variability in Women with Systemic Lupus Erythematosus: Association with Health-Related Parameters and Effects of Aerobic Exercise.

Abnormal heart rate variability (HRV) has been observed in patients with systemic lupus erythematosus (SLE). In a combined cross-sectional and interventional study approach, we investigated the association of HRV with inflammation and oxidative stress markers, patient-reported outcomes, and the effect of 12 weeks of aerobic exercise in HRV. Fifty-five women with SLE (mean age 43.5 ± 14.0 years) were assigned to either aerobic exercise (n = 26) or usual care (n = 29) in a non-randomized trial. HRV was assessed using a heart rate monitor during 10 min, inflammatory and oxidative stress markers were obtained, psychological stress (Perceived Stress Scale), sleep quality (Pittsburg Sleep Quality Index), fatigue (Multidimensional Fatigue Inventory), depressive symptoms (Beck Depression Inventory), and quality of life (36-item Short-Form Health Survey) were also assessed. Low frequency to high frequency power (LFHF) ratio was associated with physical fatigue (p = 0.019). Sample entropy was inversely associated with high-sensitivity C-reactive protein (p = 0.014) and myeloperoxidase (p = 0.007). There were no significant between-group differences in the changes in HRV derived parameters after the exercise intervention. High-sensitivity C-reactive protein and myeloperoxidase were negatively related to sample entropy and physical fatigue was positively related to LFHF ratio. However, an exercise intervention of 12 weeks of aerobic training did not produce any changes in HRV derived parameters in women with SLE in comparison to a control group.

Muscular Strength and Cardiovascular Disease: AN UPDATED STATE-OF-THE-ART NARRATIVE REVIEW.

This review discusses the associations of muscular strength (MusS) with cardiovascular disease (CVD), CVD-related death, and all-cause mortality, as well as CVD risk factors, such as metabolic syndrome, diabetes, obesity, and hypertension. We then briefly review the role of resistance exercise training in modulating CVD risk factors and incident CVD.The role of MusS has been investigated over the years, as it relates to the risk to develop CVD and CVD risk factors. Reduced MusS, also known as dynapenia, has been associated with increased risk for CVD, CVD-related mortality, and all-cause mortality. Moreover, reduced MusS is associated with increased cardiometabolic risk. The majority of the studies investigating the role of MusS with cardiometabolic risk, however, are observational studies, not allowing to ultimately determine association versus causation. Importantly, MusS is also essential for the identification of nutritional status and body composition abnormalities, such as frailty and sarcopenia, which are major risk factors for CVD.

Prediction of cardiovascular health by non-exercise estimated cardiorespiratory fitness.

OBJECTIVE: To estimate the incidence of major biological cardiovascular disease (CVD) risk factors in adults using non-exercise estimated cardiorespiratory fitness (eCRF). METHODS: 200 039 healthy people (99 957 women), aged ≥18 years (38.5±12.1 years) from the Taiwan MJ Cohort. eCRF was estimated with validated algorithms. Biological CVD risk factors, including hypertension (HTN), hypercholesterolemia, atherogenic dyslipidaemia, type 2 diabetes mellitus (T2DM) and systemic inflammation, were assessed by standardised physical examinations and laboratory tests. RESULTS: In a basic model, baseline eCRF was inversely associated with the incidence of each CVD risk factor in both men and women (HR per 1 metabolic equivalent (MET) increase in eCRF ranged from 0.53 for T2DM in women to 0.96 for hypercholesterolemia in women). In full adjusted models, the associations were attenuated but remained statistically significant, with the exception of hypercholesterolemia in women. In a subcohort of 116 313 individuals with two repeated exposure measurements, an increase in eCRF was associated in both sexes with a subsequent lower incidence of CVD risk factors (HR per 1-MET increase ranged from 0.58 to 0.91 in models adjusted for age, year of examination and baseline eCRF). Comparisons of predictive performance showed that the addition of eCRF to values of traditional CVD risk factors had relevant improvements in risk discrimination (C-index increased from 0.1% to 3.2%), mainly for HTN and T2DM risk prediction. CONCLUSIONS: eCRF and its changes predict the incidence of biological CVD risk factors, especially HTN and T2DM. Routine assessment of eCRF in clinical settings is technically feasible and might be useful for CVD prevention.

Improvements in Heart Rate Variability in Women with Obesity: Short-term Effects of Sleeve Gastrectomy.

PURPOSE: Obesity has been associated with reduced vagal function and increased sympathetic activity. Cardiac autonomic dysfunction has emerged as a major risk factor in the development of cardiovascular disease. Cardiac autonomic function (CAF) can be assessed by heart rate variability (HRV), an independent predictor of mortality based on changes in time intervals between adjacent heartbeats (RR). Bariatric surgery is considered the most effective treatment for obesity and its comorbidities, with sleeve gastrectomy (SG) being the most frequent bariatric procedure. There are few studies on HRV changes in women with obesity after SG. The aim of this study was to evaluate the short-term impact of SG on CAF and its relationship with weight loss. MATERIALS AND METHODS: An observational cohort study was conducted. Twenty-three female patients were assessed before SG and at 1 and 3 months after surgery. CAF was evaluated by analyzing HRV from 5-min records of RR intervals while the subject was supine. HRV was analyzed in time and frequency domains and with a nonlinear method. RESULTS: Patients (36.0 ± 11.1 years old, BMI 35.1 ± 3.4 kg/m2) presented higher HRV values, on average, in all domains both at 1 and 3 months after SG (p < 0.05). In addition, all anthropometric parameters improved (p < 0.001) although there was no relationship between HRV improvements and anthropometric changes. CONCLUSION: SG seems to be effective at reducing excess weight and improving HRV at the short term, and these changes are detectable as early as the first month after surgery. HRV assessment appears as a promising low-cost tool that deserves further research.

The relative age effect on physical fitness in preschool children.

The aim of the present study was to investigate the existence of a relative age effect (RAE) on physical fitness of preschoolers. Anthropometry and physical fitness were assessed in 3147 children (3-5 years old) using the PREFIT battery. Based on the birth year, participants were divided into 3year groups (3-, 4- and 5-years). Within each year group, 4quarter groups were created: quarter 1, preschoolers born from January to March; quarter 2, from April to June; quarter 3, from July to September; quarter 4, from October to December. The MANCOVA analysis revealed a main effect of year group (Wilks' λ = 0.383; F10,5996 = 369.64; p < 0.001, ηp 2 = 0.381) and of quarter (Wilks' λ = 0.874; F15,8276.6 = 27.67; p < 0.001; ηp 2 = 0.044) over the whole battery of tests. To the best of our knowledge, this is the first study to report the existence of RAE at the preschool stage. In general, performance improved as the relative age increased (i.e., those born in quarter 1 performed better than those in the other quarters). Individualization strategies should be addressed within the same academic year not only in elementary or secondary years but also in preschoolers.

Physical Exercise following bariatric surgery in women with Morbid obesity: Study protocol clinical trial (SPIRIT compliant).

BACKGROUND: Severe and morbid obesity are increasing globally, particularly in women. As BMI increases, the likelihood of anovulation is higher. The primary aim of the EMOVAR clinical trial is to examine, over the short (16 weeks) and medium (12 months) term, the effects of a supervised physical exercise program (focused primarily on aerobic and resistance training) on ovarian function in women with severe/morbid obesity who have undergone bariatric surgery. Secondary objectives are to examine the effects of the intervention on chronic inflammation, insulin resistance, arterial stiffness, physical fitness, and health-related quality of life. METHODS: This is a randomized controlled trial in which ∼40 female bariatric surgery patients, aged between 18 and 45 years old, will be included. Participants assigned to the experimental group will perform a total of 48 sessions of supervised concurrent (strength and aerobic) training (3 sessions/week, 60 min/session) spread over 16 weeks. Patients assigned to the control group will receive lifestyle recommendations. Outcomes will be assessed at baseline, week 16 (i.e., after the exercise intervention) and 12 months after surgery. The primary outcome is ovarian function using the Sex-Hormone Binding Globuline, measured in serum. Secondary outcomes are serum levels of anti-mullerian hormone, TSH, T4, FSH, LH, estradiol, prolactine, and free androgen index, as well as oocyte count, the diameters of both ovaries, endometrial thickness, and uterine arterial pulsatility index (obtained from a transvaginal ultrasound), the duration of menstrual bleeding and menstrual cycle duration (obtained by personal interview) and hirsutism (Ferriman Gallwey Scale). Other secondary outcomes include serum markers of chronic inflammation and insulin resistance (i.e., C-reactive protein, interleukin 6, tumor necrosis factor-alpha, leptin, glomerular sedimentation rate, glucose, insulin and the HOMA-IR), arterial stiffness, systolic, diastolic and mean blood pressure, body composition, and total weight loss. Physical fitness (including cardiorespiratory fitness, muscular strength, and flexibility), health-related quality of life (SF-36 v2) and sexual function (Female Sexual Function Index) will also be measured. DISCUSSION: This study will provide, for the first time, relevant information on the effects of exercise training on ovarian function and underlying mechanisms in severe/morbid obese women following bariatric surgery. TRIAL REGISTRATION NUMBER: ISRCTN registry (ISRCTN27697878).

Prevalence of severe/morbid obesity and other weight status and anthropometric reference standards in Spanish preschool children: The PREFIT project.

BACKGROUND: Childhood obesity has become a major health problem in children under the age of 5 years. Providing reference standards would help paediatricians to detect and/or prevent health problems related to both low and high levels of body mass and to central adiposity later in life. Therefore, the aim of this study was to examine the prevalence of different weight status categories and to provide sex- and age-specific anthropometry reference standards for Spanish preschool children. METHODS: A total of 3178 preschool children (4.59±0.87 years old) participated in this study. Prevalence of different degrees of obesity (mild, severe, and morbid) and other weight status categories were determined. RESULTS: Reference standards were obtained. Prevalence of overweight and obese preschool children in the Spanish population ranged from 21.4 to 34.8%. Specifically, the obesity prevalence was 3.5, 1.2, and 1.3% of these subjects were categorized as mild, severe, and morbid obese. Sex- and age-specific reference standards for anthropometric parameters are provided for every 0.25 years (i.e. every trimester of life). CONCLUSION: Our results show a high prevalence of overweight/obese preschoolers. The provided sex- and age-specific anthropometric reference standards could help paediatricians to track and monitor anthropometric changes at this early stage in order to prevent overweight/obesity.

Supervised exercise following bariatric surgery in morbid obese adults: CERT-based exercise study protocol of the EFIBAR randomised controlled trial.

BACKGROUND: There is increasing evidence of weight regain in patients after bariatric surgery (BS), generally occurring from 12 to 24 months postoperatively. Postoperative exercise has been suggested to ad long-term weight maintenance and to improve physical function in BS patients. However, there are a limited number of intervention studies investigating the possible benefits of exercise in this population. The aim of the current report is to provide a comprehensive CERT (Consensus on Exercise Reporting Template)-based description of the rationale and details of the exercise programme implemented in the EFIBAR Study (Ejercicio FÍsico tras cirugía BARiátrica), a randomised controlled trial investigating the effects of a 16-week supervised concurrent (aerobic and strength) exercise intervention program on weight loss (primary outcome), body composition, cardiometabolic risk, physical fitness, physical activity and quality of life (secondary outcomes) in patients with severe/morbid obesity following bariatric surgery. METHODS: A total of 80 BS patients [60-80% expected women, aged 18 to 60 years, body mass index (BMI) ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbid conditions)] will be enrolled in the EFIBAR Randomized Control Trial (RCT). Participants allocated in the exercise group (n = 40) will undertake a 16-week supervised concurrent (strength and aerobic) exercise programme (three sessions/week, 60 min/session), starting 7 to 14 days after surgery. The rationale of the exercise programme will be described following the CERT criteria detailing the 16 key items. The study has been reviewed and approved by the Ethics Committee of the Torrecárdenas University Hospital (Almería, Spain) (ref. N° 76/2016). DISCUSSION: The present study details the exercise programme of the EFIBAR RCT, which may serve: 1) exercise professionals who would like to implement an evidence-based exercise programme for BS patients, and 2) as an example of the application of the CERT criteria. TRIAL REGISTRATION: The trial was prospectively registered at Clinicaltrials.gov NCT03497546 on April 13, 2018.

Correction to: Effects of Exercise Training on Weight Loss in Patients Who Have Undergone Bariatric Surgery: a Systematic Review and Meta-Analysis of Controlled Trials.

In the original article the name of author Enrique G. Artero was misspelled.

Influence of Body Composition on Arterial Stiffness in Middle-Aged Adults: Healthy UAL Cross-Sectional Study.

Background and objectives: Several anthropometric and body composition parameters have been linked to arterial stiffness (AS) as a biomarker of cardiovascular disease. However, little is known about which of these closely related factors is more strongly associated with AS. The aim of the present study was to analyze the relationship of different anthropometric and body composition parameters with AS in middle-aged adults. Materials and Methods: This cross-sectional study included 186 middle-aged participants (85 women, 101 men; age = 42.8 ± 12.6 years) evaluated as part of the Healthy UAL study, a population study conducted at the University of Almería with the main purpose of analyzing the etiology and risk factors associated with cardio-metabolic diseases. Anthropometric measures included neck, waist, and hip circumferences, as well as the waist-to-height ratio (WHtr). Bioimpedance-derived parameters included fat-free mass index (FFMI), fat mass index (FMI), and percent of body fat (%BF). AS was measured by pulse wave velocity (PWV). The relationships of interest were examined through stepwise regression analyses in which age and sex were also introduced as potential confounders. Results: Neck circumference (in the anthropometric model; R2: 0.889; ß: age = 0.855, neck = 0.204) and FFMI (in the bio-impedance model; R2: 0.891; ß: age = 0.906, FFMI = 0.199) emerged as significant cross-sectional predictors of AS. When all parameters were included together (both anthropometry and bio-impedance), both neck circumference and FFMI appeared again as being significantly associated with AS (R2: 0.894; ß: age = 0.882, FFMI = 0.126, neck = 0.093). Conclusion: It was concluded that FFMI and neck circumference are correlated with AS regardless of potential confounders and other anthropometric and bioimpedance-derived parameters in middle-aged adults.

Muscle strength field-based tests to identify European adolescents at risk of metabolic syndrome: The HELENA study.

OBJECTIVES: To determine whether handgrip strength (HG) and/or standing long jump (SLJ) are capable of detecting risk of metabolic syndrome (MetS) in European adolescents, and to identify age- and sex-specific cut points for these tests. DESIGN: Cross-sectional study. METHODS: Participants included 969 (aged 12.5-17.5 years old) adolescents from 9 European countries (n = 520 girls). Absolute and relative HG and SLJ tests were used to assess upper and lower muscle strength, respectively. MetS status was determined using the age- and sex-specific cut points proposed by Jolliffe and Janssen´s, Additionally, we computed a continuous cardiometabolic risk index with the average z-score of four cardiometabolic risk factors: Wait circumference, mean arterial pressure, triglycerides/high-density lipoprotein cholesterol, and fasting insulin. RESULTS: The prevalence of MetS was 3.1% in European adolescents. Relative HG and absolute SLJ were the best tests for detecting the presence of MetS (Area under the receiver operating characteristic (AUC) = 0.799, 95%CI:0.773-0.824; and AUC = 0.695 95%CI:0.665-0.724), respectively) and elevated cardiometabolic risk index (AUC = 0.873, 95%CI:0.838-0.902; and AUC = 0.728 95%CI:0.698-0.756), respectively) and, regardless of cardiorespiratory fitness. We provide age- and sex-specific cut points of upper and lower muscle strength for European adolescents to identify the presence of MetS and elevated cardiometabolic risk index. CONCLUSIONS: The proposed health-related cut points could be used as a starting point to define health-related levels of upper and lower muscle strength in adolescents. Likewise, the diagnostic statistics provided herein can be used to offer feedback to adolescents, parents, and education and health professionals about what it means to meet or fail test standards.

Associations between objectively measured and self-reported sleep with academic and cognitive performance in adolescents: DADOS study.

Adequate sleep has been positively related with health and school achievement outcomes during adolescence. The aim of this study was to investigate the associations of objectively measured and self-reported sleep duration and quality with academic and cognitive performance in adolescents. This study was conducted with 257 adolescents (13.9 ±â€…0.3 years) from the DADOS study (Deporte, ADOlescencia y Salud). Objectively measured and self-reported sleep duration and quality were obtained by a wrist-worn GENEActiv accelerometer and the Spanish version of Pittsburgh Sleep Quality Index questionnaire, respectively. Academic performance was analysed through school records using four indicators: math, language, science and grade point average score. Cognitive performance was measured using the Spanish version of the "SRA Test of Educational Ability". After Benjamini-Hochberg correction for the false discovery rate, objectively measured sleep duration was negatively associated with verbal ability (ß = -0.179, p = .004), whilst self-reported sleep quality was positively associated with academic performance (ß ranging from 0.209 to 0.273; all p < .001). These associations remained significant after further controlling for physical fitness and physical activity. Conversely, there were no associations between self-reported sleep duration and objective sleep quality with academic and cognitive performance. Our findings fit in line with previous research showing that sleep quality may play an important role on adolescents' academic performance. Further interventional research is needed to clarify the mechanisms by which sleep is related to academic performance in youth.

Grip strength cutpoints for youth based on a clinically relevant bone health outcome.

The National Academy of Medicine recommends the handgrip for school-based surveillance of muscle strength for bone health. We established grip strength cutpoints that are linked to bone health in both US and European youth. These cutpoints could serve as a potential set of standards for surveillance and clinical applications. PURPOSE: The U.S. National Academy of Medicine and experts in Europe recommend the use of grip strength as a valuable and accessible musculoskeletal fitness measure due to its association with bone health. This is the first study to facilitate this recommendation by developing bone health-related grip strength cutpoints for youth based on empirical associations with the well accepted marker of bone development, i.e., height-adjusted total body less head bone mineral content (TBLH_BMC). METHODS: A purposive sample of healthy youth from Midwest USA (n = 433 youth; 14.1 ± 2.3 years; 1998-2004) and a random sample of healthy adolescents from Zaragoza, Spain (n = 355 youth; 14.9 ± 1.2 years; 2006-2007) were used to develop and test cut-points. Participants' grip strength was measured using a hand-held dynamometer while height-adjusted TBLH_BMC was determined using dual-energy x-ray absorptiometry. Grip strength scores were linked to TBLH_BMC using receiver operator characteristic curves, and grip strength cutpoints were tested based on the area under the curve (AUC), sensitivity (Se), specificity (Sp), and predictive odds ratios. All analyses were conducted in 2016. RESULTS: The AUC approximated or exceeded 0.80 for grip strength cutpoints, and the associated Se and Sp indices ranged from 53.6 to 92.5%. Sensitivity and Sp remained similar in the validation sample and those not meeting the grip strength cutpoints were five to eight times more likely to have insufficient TBLH_BMC, depending on their sex and cutpoint being considered. CONCLUSIONS: Grip strength is strongly related to TBLH_BMC, and the proposed cutpoints demonstrated acceptable classification accuracy for screening healthy youth and tracking healthy bone development in community settings. The utility of the cutpoints should be further examined in more diverse populations of youth.

The Effect of Physical Activity Interventions on Glycosylated Haemoglobin (HbA1c) in Non-diabetic Populations: A Systematic Review and Meta-analysis.

BACKGROUND: Physical activity is widely perceived to be beneficial for preventing type 2 diabetes mellitus and for controlling glycaemic levels in patients with type 2 diabetes, but evidence supporting a positive effect in the control of glycaemic levels in healthy people is rather weak. The aim of this review was to estimate the effect of physical activity on glycaemic control measured by glycosylated haemoglobin (HbA1c) levels in non-diabetic populations, and to determine which type of physical activity has a greater influence on glycaemic control. METHODS: We systematically searched the MEDLINE, EMBASE, Cochrane Library and Web of Science databases, from inception to May 2017, for experimental studies addressing the effect of physical activity on glycaemic control measured by HbA1c levels in non-diabetic populations. The DerSimonian and Laird method was used to compute pooled estimates of effect size (ES) and respective 95% confidence intervals (CIs). The effect of physical activity on HbA1c levels was estimated in two ways: (1) physical activity intervention versus control; and (2) physical activity pre-post intervention. Additionally, subgroup analyses were performed based on age of participants and different aspects of the intervention. RESULTS: Fifteen published studies were included in the meta-analysis. In analyses comparing physical activity intervention and control, we found a decrease of HbA1c levels in favour of the intervention group (ES = 0.32; 95% CI 0.01-0.62) with substantial heterogeneity (I2 = 63.2%; p = 0.008). In the pre-post analysis, there was a decrease in HbA1c levels post physical activity intervention (ES = 0.17; 95% CI 0.01-0.33) with low heterogeneity (I2 = 25.8%; p = 0.164). Additionally, for physical activity intervention versus control, a decrease in HbA1c levels was observed in resistance exercise and in intervention length below 12 weeks. Furthermore, for pre-post effect analyses, a decrease in HbA1c levels was observed in the supervised physical activity programme, other type of exercises, intervention length below 12 weeks and exercise intervention week duration above 150 min subgroups. CONCLUSIONS: This systematic review and meta-analysis provides an overview of the evidence supporting physical activity as a suitable intervention for glycaemic control as measured by HbA1c levels in non-diabetic populations. TRIAL REGISTRATION: PROSPERO CRD42016050991.