Diagnostic performance of SARC-F and SARC-CalF in screening for sarcopenia in older adults in Northern Brazil.

To compare the performance of SARC-F and SARC-CalF as screening tools for sarcopenia. Cross-sectional study with a convenience sample of 312 community-dwelling older people. Sarcopenia was defined as low handgrip strength (HGS) or low gait speed (GS ≤ 0.8 m/s). HGS was measured by dynamometry and GS by the 4-m walking speed test. For HGS, six criteria (C) were used to identify sarcopenia in men/women: CI: < 27 kg/16 kg; CII: < 35.5 kg/20.0 kg; CIII: grip over body mass index < 1.05/< 0.79; CIV: grip strength over total body fat < 1.66/< 0.65; CV: grip over bodyweight < 0.45/< 0.34; CVI: < 27 kg/16 kg and low skeletal muscle mass index (SMMI); CI and CVI defined according to the European Working Group on sarcopenia in older people and the rest according to the sarcopenia definition and outcomes Consortium. For sarcopenia screening, the SARC-F (≥ 4 points) and the SARC-CalF (≥ 11 points) were used. The kappa analysis revealed no agreement between the SARC-F and the various criteria for the identification of sarcopenia in men. The same lack of agreement was observed in women with some exceptions: CI = 0.161 ± 0.074, p = 0.020; GS = 0.209 ± 0.076, p = 0.003. Concerning the Cohen's kappa between the SARC-Calf and the reference criteria of sarcopenia, the following coefficients were observed as significant for women: CI = 0.201 ± 0.069, p = 0.003; CII = 0.186 ± 0.064, p = 0.005; GS = 0.273 ± 0.068, p = 0.0001; and for men: CII = 0.139 ± 0.053, p = 0.021; GS = 0.223 ± 0.099, p = 0.011. ROC curves revealed the SARC-Calf with acceptable discrimination and reasonable sarcopenia predictive capacity considering a cutoff value of 10.5 in both men (AUC: 67.5%, p = 0.022; Se = 52.9%; Sp = 76.8%) and women (AUC: 72.4%, p < 0.001; Se = 63%; Sp = 68.5%) concerning GS. The SARC-CalF performed better than the SARC-F for screening sarcopenia in the population ≥ 60 years of age in the Amazonas, measured through walking slowness.

Compensatory mechanisms from different exercise intensities in type 2 diabetes: a secondary analysis of a 1-year randomized controlled trial.

AIMS: This investigation aimed to determine the effect of different intensities of training on non-exercise physical activity (NEPA) and estimated thermogenesis (NEAT) from a 1-year exercise randomized controlled trial (RCT) in individuals with type 2 diabetes mellitus (T2DM) on non-training days. Additionally, changes in NEPA and estimated NEAT in those who failed (low-responders) or succeeded (high-responders) in attaining exercise-derived clinically meaningful reductions in body weight (BW) and fat mass (FM) (i.e., 6% for FM and 3% for BW) was assessed. METHODS: Individuals with T2DM (n = 80) were enrolled in a RCT with three groups: resistance training combined with moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT) and a control group. Of the 80 participants, 56 (completed data) were considered for this secondary analysis. NEPA and estimated NEAT were obtained by accelerometry and body composition through dual-energy X-ray absorptiometry. RESULTS: After adjustments, no time*group interactions were found for estimated NEAT in the MICT (ß = - 5.33, p = 0.366) and HIIT (ß = - 5.70, p = 0.283), as well as for NEPA in the MICT (ß = - 452.83, p = 0.833) and HIIT (ß = - 2770.76, p = 0.201), when compared to controls. No compensatory changes in NEPA and estimated NEAT were observed when considering both low-responders and high-responders to FM and BW when compared to controls. CONCLUSIONS: Both MICT and HIIT did not result in any compensatory changes in estimated NEAT and NEPA with the intervention on non-training days. Moreover, no changes in estimated NEAT and NEPA were found when categorizing our participants as low-responders and high-responders to FM and BW when compared to controls. Trial registration clinicaltrials.gov ID. NCT03144505.

Longitudinal association between grip strength and the risk of heart diseases among European middle-aged and older adults.

BACKGROUND: Few multi-country European studies have investigated the association between grip strength and heart diseases incidence. Thus, the aim of this study is to analyse the longitudinal relationship between grip strength and the diagnosis of heart diseases in European middle-aged and older adults. METHOD: A prospective cohort study was conducted using data from the Survey of Health, Aging and Retirement in Europe (2004-2017). Participants were 20,829 middle-aged and older adults from 12 countries. GS was objectively measured by a dynamometer and heart diseases diagnosis was self-reported. Incidence rate of heart diseases was calculated and a Cox proportional hazard regression was performed. RESULTS: The heart diseases incidence rate decreased from 930 per 100,000 person-years in the lowest quartile to 380 per 100,000 person-years in the highest grip strength quartile. During the 13 years of follow-up, compared to being in the lowest grip strength quartile, being in the highest quartile decreased the hazard of being diagnosed with a heart disease in 36 % (95 % confidence interval [CI]: 0.53, 0.78) for the whole sample, 35 % (95 % CI: 0.51, 0.84) for men and 46 % (95 % CI: 0.40, 0.73) for women. CONCLUSIONS: Grip strength seems to be inversely associated with the incidence of heart diseases among European middle-aged and older adults. Scientific evidence has highlighted the potential role of grip strength as a risk stratifying measure for heart diseases, suggesting its potential to be included in the cardiovascular risk scores used in primary care. However, further research is still needed to clarify it.

A combined training program's effect on anthropometry, body composition, physical fitness and blood pressure in elite police.

BACKGROUND: Combined training (CT) simultaneously associates aerobic and strength exercises. Worldwide, studies on CT´s on Police officers' physical fitness are scarce. This study aims to measure a 4-month CT program's impact in the Close Protection Unit of the Portuguese Elite Police. METHODS: A pre-and post-test study included 32 participants (mean age 30.1±2.7 years old). Anthropometry, body composition, physical fitness, and blood pressure assessments were collected. Statistical analysis was performed using IBM Statistical Package for Social Sciences (SPSS, 26.0) with a significance level at p≤0.05. RESULTS: The main results showed an improvement in anthropometrics; aerobic capacity, strength, muscular endurance, and systolic blood pressure. However, a lean mass decrease, a fat mass increase, and worse results in other bioimpedance measures were observed. CONCLUSIONS: In this study, the poor body composition results may imply a closer look for health concerns, although physical fitness has improved. Thus, it might be suggested that a CT program is helpful to increase physical fitness in elite police officers. Yet, improvements for its future application can be suggested, namely to include and address hydration level, nutrition, and rest/sleep moments. Moreover, because a high physical fitness level is needed in these population throughout their lifespan, ministerial policies should develop specific training programs, that can reduce morbidity and premature mortality, and have a major cos-teffectiveness impact on public health.

Physical fitness tests as an indicator of potential athletes in a large sample of youth.

BACKGROUND: Promoting youth sports participation is an excellent strategy to improve health and high-level sports competition around the world. AIMS: The aim of this study was to analyse the potential of commonly used physical-fitness (PF) tests to discriminate against athletes from non-athletes in young populations. MATERIAL AND METHODS: One thousand eight hundred and thirty-one youth people were analysed (boys: 514 non-athletes and 401 athletes; girls: 722 non-athletes and 194 athletes) aged 10-18 years (y). Cardiorespiratory fitness (CRF), muscular fitness (MF), agility and speed were tested using PF tests. RESULTS: Application of receiver operating characteristics curves was used to assess the discriminatory potential of each PF for distinguishing athletes from non-athletes, with an area under the curve (AUC) higher than 65% (0.65). In the oldest groups (≥16 y), the speed test at 20 m in boys (AUC = 0.70) and horizontal jump test in girls (AUC = 0.75) were the best discriminators, while the push-up-test (AUC 10-11 y boys = 0.68, AUC 14-15 y boys = 0.68, AUC 10-11 y girls = 0.73, AUC 12-13 y girls = 0.87) and the PACER (AUC boys: 12-13 y = 0.68 and AUC girls 14-15 y = 0.73) appeared to be better discriminators than other PF tests, for the younger age-groups. CONCLUSION: The speed-test at 20 m and the horizontal-jump were the best PF to identify older adolescents with athletic potential, while the PACER and push-up tests were the most discriminatory for the younger adolescents.

Grip strength as a predictor of depressive symptoms among vulnerable elderly Europeans with musculoskeletal conditions.

The present study aimed to investigate the grip strength (GS) discrimination capacity and cutoffs points for depressive symptoms among vulnerable elderly individuals with musculoskeletal conditions. The Survey of Health, Aging, and Retirement in Europe wave 6 was analyzed. GS was measured by a handgrip dynamometer, and EURO-D scale was used to assess depressive symptoms. GS cutoff values for depressive symptoms were calculated using the receiver operating characteristics curve. 2206 participants, mean age 74.0 (73.7-74.3), 78.8% with osteoarthritis/other rheumatism, enrolled in the study. Sensitivity varies between 0.44 (men, ≥ 85 years) and 0.82 (men, 75-84 years), and specificity varying between 0.35 (women, 75-84 years) and 0.70 (men 75-84 years). GS is associated with depressive symptoms just for women and it is not possible to use a GS cutoff point for screening depressive symptoms for vulnerable men and women with musculoskeletal conditions over the age of 65 years.

Interindividual Variability in Fat Mass Response to a 1-Year Randomized Controlled Trial With Different Exercise Intensities in Type 2 Diabetes: Implications on Glycemic Control and Vascular Function.

Purpose: Little is known about the interindividual variability in fat mass (FM) loss in response to high-intensity interval training (HIIT) and moderate continuous training (MCT) in individuals with type 2 diabetes mellitus (T2DM). Moreover, the impact on health-related outcomes in those who fail to reduce FM is still unclear. The aims of this investigation were (1) to assess if the individuals with T2DM who FM differed across MCT, HIIT, and control groups over a 1-year intervention and (2) to assess the changes on glycemic control and vascular function in the exercising patients who failed to lose FM. Methods: Adults with T2DM were randomized into a 1-year intervention involving a control group (n=22), MCT with resistance training (RT; n=21), and HIIT with RT (n=19). FM was assessed using dual-energy X-ray absorptiometry and a change in total body FM above the typical error was used to categorize FM responders. Glycemic control and vascular stiffness and structure were assessed. A chi-square test and generalized estimating equations were used to model the outcomes. Results: Both MCT (n=10) and HIIT (n=10) had a similar proportion of individuals who were categorized as high responders for FM, with the percent change in FM on average -5.0±9.6% for the MCT and -6.0±12.1% for the HIIT, which differed from the control group (0.2±7.6%) after a 1-year intervention (p<0.05). A time-by-group interaction for carotid artery intima-media thickness (cIMT) (p for interaction=0.042) and lower-limb pulse wave velocity (LL PWV; p for interaction=0.010) between those categorized as low FM responders and the control group. However, an interaction was observed between the high responders for FM loss and controls for both brachial and carotid hemodynamic indices, as well as in cIMT, carotid distensibility coefficient, carotid beta index, and LL PWV (p for interactions <0.05). No interactions were found for glycaemic indices (p for interaction >0.05). Conclusion: Our results suggest that the number of FM responders did not differ between the MCT or HIIT, compared to the control, following a 1-year exercise intervention in individuals with T2DM. However, low responders to FM may still derive reductions in arterial stiffness and structure. Clinical Trial Registration: Comparing Moderate and High-intensity Interval Training Protocols on Biomarkers in Type 2 Diabetes Patients (D2FIT study) - number: NCT03144505 (https://clinicaltrials.gov/ct2/show/NCT03144505).

A Systematic Review of the Association Between Muscular Fitness and Telomere Length Across the Adult Lifespan.

This study aimed to systematically review the association between telomere length (TL) and muscular fitness. In October 2020, an articles search was applied to PubMed, Scopus, and Web of Science. Eligibility criteria included: cross-sectional, prospective, and experimental study design; outcomes included TL; results expressed the relationship between muscular fitness and TL; studies published in English, Portuguese, or Spanish. Nine studies were included in the review. Results from the four prospective studies are mixed. In one study, the changes in TL were associated with grip strength. Another study concluded that longer mid-life TL was associated with increased grip strength later in life. However, in the other two studies, the association between TL and sarcopenia was not strong. Nevertheless, longer TL was associated with a slower decline in grip strength in older people. From the four cross-sectional studies, three indicated that TL was associated with muscular fitness. On the other hand, in a study with powerlifters, TL remained within the range of values found in subjects with no history of regular strength training, supporting the notion that muscular fitness was not associated with TL. The cross-sectional and prospective studies showed that the relationship between TL and muscular fitness is not conclusive. It seems that there is a positive association between TL and muscular fitness in middle-aged and older adults. However, among younger adults, this relationship was not observed.

Exploring grip strength as a predictor of depression in middle-aged and older adults.

Grip strength (GS) is an indicator of health and vulnerability and inversely associated with depressive symptoms. The aim of this study was to explore GS discrimination capacity for depression; and possible GS cut-off values for depression by sex and age group. Data from 2011 and 2015 on 20,598 (10,416 women) middle-aged and older adults from 14 European countries was analysed. GS was assessed by dynamometer, and depressive symptoms using the EURO-D scale. GS cut-off values for depression were calculated and logistic regression models were used to quantify the odds of having depression in 2011 and in 2015 according to being bellow or above the cut-off value. GS had a weak discriminant capacity for depression, with the area under the curve varying between 0.54 and 0.60 (p < 0.001). Sensitivity varied between 0.57 and 0.74; specificity varied between 0.46 and 0.66. GS cut-off values for discriminating depression were 43.5 kg for men and 29.5 kg for women aged 50-64 years, 39.5 kg for men and 22.5 kg for women aged ≥ 65 years. Having GS above the cut-off represents significant lower odds of depression in 2011 and 4 years later, in 2015. Healthcare practitioners and epidemiologic researchers may consider the low GS cut-off values to screen for potential depression risk. However, due to its weak discriminant values these cut-offs should not be used to identify depression.

A hierarchy of correlates impacting adults' sensor-based physical activity and sedentary time.

Investigation into correlates across all levels of the socio-ecological model predictive of objectively measured physical activity has rarely been assessed in adults. While considering a diversity of correlates, we determined which correlates best predict sensor-based moderate-to-vigorous physical activity (MVPA) and sedentary-time (ST) in adults. A Chi-squared Automatic Interaction Detection algorithm was used to hierarchize the correlates associated with high ST (≥66.6thpercentile) and sufficient MVPA (≥150 min/week) in 865 adults. The main correlate predictive of being active was currently partaking in sport/exercise. The following relevant correlates were being male for the exercisers and having trees in the neighbourhood for the non-exercisers. The final correlate to boost male exercisers' MVPA was having lots of shops in the neighbourhood and not having television in the bedroom for women. The primary correlate for high ST was job activity level, with individuals having highly active jobs being less likely to exhibit high levels of ST; being single, male, and a former athlete also increased the chances of being highly sedentary. To increase adults' MVPA, promotion of sport participation, neighbourhood landscape planning, shop availability, as well as limiting television in the bedroom must be prioritized. For counteracting ST, increasing workplace activity level is warranted.

Field-Based Health-Related Physical Fitness Tests in Children and Adolescents: A Systematic Review.

Physical fitness (PF) is a multi-component construct and a biomarker of health. Worse PF is related to vulnerability and predicts worse academic achievements. Thus, assessing PF is important to monitor health in youth. This systematic review aimed to identify and inform physical education, health professionals and entities about existing PF batteries and field-tests that can be used in school settings. A comprehensive literature search was carried out in five electronic databases (Academic Search Complete, Education Resources Information Center, PubMed, Scopus, and Web of Science) to identify PF battery protocols that can be carried out in the school setting. Overall, 24 PF batteries were identified. Regarding the PF components assessed, only cardiorespiratory fitness and upper body strength were contemplated in all batteries. Middle-body strength and lower body strength were presented in most batteries (21 and 19 of 24, respectively). Agility (16 of 24) and body composition (16 of 24) were also considered in several batteries, although to a lesser extent. Flexibility (14 of 24) and speed (12 of 24) were the PF components less represented in the batteries. Among the 24 identified PF batteries, 81 PF tests assessing the different PF components were encountered. The advances in the PF field-based assessment in school settings and health in youth resulted in the amplification of the number of existing batteries. Considering the connection between PF and health and the opportunity that the school setting provides to assess fitness in children and adolescents, there is a need for standardization and a consensus of PF assessments in this specific setting.

Sensor-based physical activity, sedentary time, and reported cell phone screen time: A hierarchy of correlates in youth.

BACKGROUND: Evidence on correlates relies on subjective metrics and fails to include correlates across all levels of the ecologic model. We determined which correlates best predict sensor-based physical activity (PA), sedentary time (ST), and self-reported cell phone screen time (CST) in a large sample of youth, while considering a multiplicity of correlates. METHODS: Using sensor-based accelerometry, we assessed the PA and ST of 2179 youths. A χ2 automatic interaction detection algorithm was used to hierarchize the correlates associated with too much ST (> 50th percentile), insufficient moderate-to-vigorous PA (MVPA) (<60 min/day), and prolonged CST (≥2 h/day). RESULTS: Among youth 10-14 years old, the correlates for being inactive consisted of being a girl, not having sport facilities in the neighborhood, and not perceiving the neighborhood as a safe place, whereas in the youth 15-18 years old, the correlate for being inactive was not performing sports (9.7% chance of being active). The correlates for predicting high ST in the younger group was not performing sports (55.8% chance for high ST), and in the older group, the correlates were not owning a pet, perceiving the neighborhood as safe, and having inactive parents (63.7% chance for high ST). In the younger group, the greatest chances of having high CST were among those who were in the last elementary school years, who were girls, and who did not have friends in the neighborhood (73.1% chance for high CST), whereas in the older group, the greatest chance for having high CST was among those who were girls and had a TV in the bedroom (74.3% chance for high CST). CONCLUSION: To counteract ST and boost MVPA among youths, a specific focus on girls, the promotion of sport participation and facilities, neighborhood safety, and involvement of family must be prioritized.

Fitness, physical activity, or sedentary patterns? Integrated analysis with obesity surrogates in a large youth sample.

OBJECTIVE: Physical fitness (PF) and physical activity (PA) are inversely associated with body mass index and waist circumference (WC), whereas sedentary time (ST) seems to boost obesity in youth. The aim was to examine the associations of each selected PF test, PA-related exposures, and specific ST patterns with obesity and determine the most relevant ones, in a large sample of a school-aged adolescent. METHODS: The sample consisted of 2696 Portuguese youth aged 10 to 18 years. Height, weight, and WC were measured. PA and ST components were measured using accelerometry. PF was evaluated using a battery of tests. RESULTS: The Progressive Aerobic Cardiovascular Endurance Run (PACER) and push-up tests seemed to be the exposures that presented the strongest and more consistent associations with obesity, independent of PA/ST profiles (P < .05). The second exposure of relevance for adolescent obesity level was the breaks in ST with a negative relationship regardless of PA/PF profiles (P < .05). Finally, ST accumulated in periods of <30 minutes, and moderate-to-vigorous PA were favorably associated with obesity, independent of ST/PF. CONCLUSIONS: Independent of PA and ST, cardiorespiratory fitness (CRF), measured by PACER, was associated with obesity markers. This may be in part due to the dependence of PACER performance on adiposity. Also, limiting prolonged ST and promoting interruptions in this behavior were associated with obesity. These associations suggest that future research should examine other strategies beyond PA promotion for tackling obesity that consider CRF and breaking ST.

Grip Strength and Depression Symptoms Among Middle-Age and Older Adults.

OBJECTIVE: To analyze the relationship between grip strength and symptoms of depression, considering sex and age, in adults from 18 countries. METHODS: Cross-sectional data for adults 50 years and older from the Survey of Health, Aging, and Retirement in Europe wave 6 (collected in 2015) were analyzed. Grip strength was measured twice on each hand using a handgrip dynamometer. The EURO-D 12-item scale was used to measure depression symptoms. Multivariable logistic regression analysis was conducted. Data analyses were conducted between November 5, 2019, and February 7, 2020. RESULTS: Men and women who were in quartiles 2, 3, and 4 of grip strength were less likely to have depression symptoms than those in the first quartile of grip strength. Having more grip strength decreased the odds of depression symptoms by 30% (odds ratio 0.70; 95% CI, 0.65 to 0.77) and 47% (odds ratio, 0.53; 95% CI, 0.49 to 0.57) for adults aged 50 to 64 years and 65 years and older, respectively, when compared with those with the lowest grip strength. The negative relationship between strong grip strength and depression symptoms was observed among men and women younger and older than 65 years. CONCLUSION: There was an association between grip strength and depression symptoms. For clinical practice and geriatric health professionals, assessing adults' grip strength can be used as a signal to screen for physical and mental health.

Promoting Health-Related Cardiorespiratory Fitness in Physical Education: The Role of Class Intensity and Habitual Physical Activity.

Physical education (PE) has the potential to promote health-related fitness, however, its contribution is still not clear. The aim of this study was to assess whether students' health-related cardiorespiratory fitness (CRF) improved from the beginning to the end of the school year, and to examine the role of PE class intensity and habitual physical activity (PA) in promoting students' CRF. This observational study employed a longitudinal design. Participants were 212 7th and 8th grade students (105 boys), mean age 12.9 years old, followed during one school year, from September 2017 to June 2018. The Progressive Aerobic Cardiovascular Endurance Run (PACER) was used to assess CRF at baseline and follow-up. PA was measured using accelerometers. PE class intensity was assessed using the System for Observing Fitness Instruction Time. Findings indicated that from the beginning to the end of the school year, a greater percentage of participants were in the CRF healthy fitness zone (73.1% to 79.7%, p = 0.022). Among boys, participating in organized sports (B = 4.61, 95% confidence interval [CI]: 0.33, 8.88) and the percentage of PE time being very active (B = 0.90, 95% CI: 0.44, 1.35) were positively associated with the change in PACER laps. Among girls, daily vigorous PA (B = 0.38, 95% CI: 0.15, 0.60) and participating in organized sports (B = 4.10, 95% CI: 0.93, 7.27) were also positively associated with PACER change, while being overweight or obese (B = -5.11, 95% CI: -8.28, -1.93) was negatively associated. In conclusion, PE was demonstrated to have a positive role in the promotion of CRF, especially among boys, while for girls, habitual PA seems to have a greater contribution. Nevertheless, results and conclusions should be considered carefully, taking into account study limitations, such as the non-direct measures of PE class intensity, CRF, and school setting.

Promoting health-related cardiorespiratory fitness in physical education: A systematic review.

BACKGROUND: This article aimed to systematically review the contribution of physical education (PE) classes to improve cardiorespiratory fitness (CRF) in children and adolescents; and to define potentially relevant factors for promoting CRF in PE classes. METHODS: Studies were identified from searches in ERIC, PubMed, SPORTDiscus, and Web of Science databases. Primary source articles, relating PE classes and CRF, published up to July 2019 in peer-reviewed journals were eligible for inclusion. Specific inclusion criteria were: (a) having cross-sectional or longitudinal and observational or interventional study designs; (b) targeting school-aged children or adolescents; (c) measuring CRF, heart rate or CRF test results as an outcome; (d) having statistical analyses of the CRF, heart rate or CRF test results outcomes reported; (e) focusing on PE classes or PE interventions that did not extended time or frequency of the classes; and (f) published in English, French, Portuguese, or Spanish. RESULTS: A total of 24 studies met the inclusion criteria. Overall, 10 studies have found a neutral effect of PE classes in students' CRF, eight studies found that PE indeed contributed to the improvement of CRF and six studies revealed mixed findings, when PE classes where controlled for others variables (e.g. body mass index, intensity). Higher intensity PE classes consistently demonstrated contributions to improving students' CRF. CONCLUSION: Review findings suggest that PE classes can contribute to the improvement of students' CRF. Intensity, age and weight status were identified as potentially relevant factors for promoting CRF in PE classes. To improve CRF, higher intensity classes should be provided.

Mediating role of physical fitness and fat mass on the associations between physical activity and bone health in youth.

We aimed to assess if the relationship between VPA and bone health is simultaneously mediated by PF and fat mass in adolescents. Bone health was assessed by quantitative ultrasound (QUS) in 412 participants (221 girls) aged 10-18 years. VPA was assessed by accelerometry and PF was measured using specific protocols from FITescola®. Fat mass (%) was assessed using two skinfolds (triceps and calf). Parallel mediation analysis was performed by Hayes' PROCESS (V.3.3-model 4) for SPSS. We observed that in boys, handgrip mediated the associations of VPA with speed of sound on the third distal radius (R-SoS). While, speed at 20 m and handgrip mediated the relationship of VPA with speed of sound on the tibial midshaft (T-SoS). Body fat (%) only acted as a mediator when handgrip integrates the mediation model. For girls, the only mediating variable for the relationship between VPA and R-SoS or T-SoS was the PACER test. Handgrip, speed and fat mass (%) in boys, and cardiorespiratory fitness in girls mediates the relationships between VPA and bone health assessed by QUS. Promoting muscular fitness and cardiorespiratory fitness and decrease of fat mass through VPA in adolescents may be an important strategy to improve bone health.

A Comparative Study of Participation in Physical Education Classes among 170,347 Adolescents from 54 Low-, Middle-, and High-Income Countries.

Given the need for comparative research on the participation of adolescents in physical education (PE) classes as a privileged space for physical activity (PA) promotion, this study sought to estimate, analyse and compare the prevalence of participation in PE classes among adolescents from 54 countries and to examine sex, age, country income and world regions disparities. Data from the Global Students Health Survey (2010-2015) were used, comprising 170,347 adolescents (90,305 girls, aged 13-17 years) from nationally representative samples of 54 countries-of which 7 are low-income, 23 lower-middle-income, 14 upper-middle-income and 10 high-income-and six world regions. The weighted percentages of adolescents participating in PE classes (never, 1-2 days/week, 3-4 days/week, 5 or more days/week) were estimated along 95% confidence intervals and compared across sex, age, country income, region, and country. Most adolescents reported to participate in PE on 1-2 days/week (55.2%), but almost 20% of adolescents reported never participating in PE. Girls, compared to boys, presented a lower prevalence for participating ≥5 days/week (girls 16.8%, boys 20.0%). The prevalence of participating in PE on ≥3 days/week was higher among adolescents aged 13-14 years when compared to adolescents aged 15-17 years (boys: 30.9% vs. 24.6%; girls: 26.1% vs. 18.2%). Concerning the countries' income, the prevalence of never participating in PE was higher in high-income countries, and participating on ≥3 days/week was higher in low-income countries, but further research is recommended. The findings suggest that national, regional and worldwide data highlight the importance of improving participation in PE, particularly for girls and older adolescents. An improved and continued monitoring of PE policies and their actual implementation is needed worldwide.

Physical Fitness and Bone Health in Young Athletes and Nonathletes.

BACKGROUND: Physical activity (PA) and physical fitness (PF) are crucial for bone health. However, children participating in competitive sports with high PA are at a greater risk of fracture from trauma or overuse. Given the importance of bone development during adolescence, associations between commonly used physical fitness tests with distal third radius (R-SoS) and midshaft tibia (T-SoS) speed of sound by quantitative ultrasound were assessed in adolescent athletes and nonathletes. HYPOTHESIS: The relationship between physical fitness tests and R-SoS and T-SoS will differ depending on sex and athletic status. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: Physical fitness of 285 boys (156 athletes) and 311 girls (74 athletes) aged 10 to 18 years was assessed through strength, speed, agility, and cardiorespiratory tests. Linear regression was used to assess the associations of physical fitness tests with R-SoS and T-SoS. RESULTS: For boys, favorable associations were observed between physical fitness tests with R-SoS in athletes and T-SoS in both athletes and nonathletes (P < 0.05). For nonathlete girls, favorable associations were found for handgrip (R-SoS and T-SoS, both P < 0.05), whereas the progressive aerobic cardiovascular endurance run, vertical jump, speed at 20 m and 40 m were only favorably associated with T-SoS. For athlete girls, the association between handgrip (P = 0.03), vertical jump, and 4 × 10 m shuttle run (P < 0.05) with T-SoS was significantly related to a bone outcome. CONCLUSION: The handgrip test and vertical jump were associated with T-SoS in boys and girls independent of sport status. These results suggest that physical fitness is associated with bone health in adolescents, particularly boys, and that the relationship between physical fitness and bone may differ depending on sex and athletic status. CLINICAL RELEVANCE: Physical fitness tests are simple, easy-to-use tools for monitoring bone health and should be used by sport and health professsionals to promote healthy sport participation and prevent bone injuries.