No changes in adolescent's sedentary behaviour across Europe between 2002 and 2017.

BACKGROUND: Public health organizations have been alerted to the high levels of sedentary behaviour (SB) among adolescents as well as to the health and social consequences of excess sedentary time. However, SB changes of the European Union (EU) adolescents over time have not been reported yet. This study aimed to identify SB of the EU adolescents (15-17 years) in four-time points (2002, 2005, 2013 and 2017) and to analyse the prevalence of SB according to the sex. METHODS: SB of 2542 adolescents (1335 boys and 1207 girls) as a whole sample and country-by-country was analysed in 2002, 2005, 2013, and 2017 using the Sport and Physical Activity EU Special Eurobarometers' data. SB was measured using the sitting time question from the short version of the International Physical Activity Questionnaire (IPAQ), such that 4h30min of daily sitting time was the delineating point to determine excess SB behaviour (≥4h30min of sitting time) or not (≤4h30min of sitting time). A χ2 test was used to compare the prevalence of SB between survey years. Furthermore, SB prevalence between sexes was analysed using a Z-Score test for two population proportions. RESULTS: The prevalence of SB among EU adolescents across each of the four survey years ranged from 74.2 and 76.8%, rates that are considered high. High levels of SB were also displayed by both sexes (girls: 76.8 to 81.2%; boys: 71.7 to 76.7%). No significant differences in the prevalence of SB among years (p > 0.05) were found for the whole sample, and for either girls or boys. Also, no significant differences in the prevalence of SB between girls and boys were found. CONCLUSION: The SB prevalence in European adolescents is extremely high (76.8% in 2017) with no differences between girls and boys. No significant improvements have been seen between 2002 and 2017. Eurobarometer should increase the adolescents' sample to make possible benchmarking comparisons among the EU countries and extend the survey to the younger children population.

High intensity interval training exercise-induced physiological changes and their potential influence on metabolic syndrome clinical biomarkers: a meta-analysis.

BACKGROUND: Despite the current debate about the effects of high intensity interval training (HIIT), HIIT elicits big morpho-physiological benefit on Metabolic Syndrome (MetS) treatment. However, no review or meta-analysis has compared the effects of HIIT to non-exercising controls in MetS variables. The aim of this study was to determine through a systematic review, the effectiveness of HIIT on MetS clinical variables in adults. METHODS: Studies had to be randomised controlled trials, lasting at least 3 weeks, and compare the effects of HIIT on at least one of the MetS clinical variables [fasting blood glucose (BG), high-density lipoprotein (HDL-C) triglyceride (TG), systolic (SBP) or diastolic blood pressure (DBP) and waist circumference (WC)] compared to a control group. The methodological quality of the studies selected was evaluated using the PEDro scale. RESULTS: Ten articles fulfilled the selection criteria, with a mean quality score on the PEDro scale of 6.7. Compared with controls, HIIT groups showed significant and relevant reductions in BG (- 0.11 mmol/L), SBP (- 4.44 mmHg), DBP (- 3.60 mmHg), and WC (- 2.26 cm). Otherwise, a slight increase was observed in HDL-C (+ 0.02 mmol/L). HIIT did not produce any significant changes in TG (- 1.29 mmol/L). CONCLUSIONS: HIIT improves certain clinical aspects in people with MetS (BG, SBP, DBP and WC) compared to people with MetS who do not perform physical exercise. Plausible physiological changes of HIIT interventions might be related with large skeletal muscle mass implication, improvements in the vasomotor control, better baroreflex control, reduction of the total peripheral resistance, increases in excess post-exercise oxygen consumption, and changes in appetite and satiety mechanisms.

Changes in sedentary behaviour in European Union adults between 2002 and 2017.

BACKGROUND: Sedentary behaviour (SB) has been identified as an important mortality risk factor. Health organizations have recognised SB as a public health challenge with major health, social, and economic consequences. Researchers have alerted the need to develop specific strategies, to monitor, prevent, and reduce SB. However, there is no systematic analysis of the SB changes in European Union adults. We aimed to examine SB changes between 2002 and 2017 in the European Union (EU) adult population. METHODS: SB prevalence (>4h30mins of sitting time/day) of 96,004 adults as a whole sample and country-by-country was analysed in 2002, 2005, 2013, and 2017 of the Sport and Physical Activity EU Special Eurobarometers' data. The SB question of a modified version of the International Physical Activity Questionnaire was considered. SB prevalence between countries and within years was analysed with a χ2 test, and SB between genders was analysed with the Z-Score test for two population proportions. RESULTS: An association between the SB prevalence and the years was found (p < 0.001), with increases for the whole sample (2002: 49.3%, 48.5-50.0 95% confidence interval (CI); 2017: 54.5%, 53.9-55.0 95% CI) and men (2002: 51.2%, 50.0-52.4 95% CI; 2017: 55.8%, 55.0-56.7 95% CI) and women (2002: 47.6%, 46.6-48.7 95% CI; 2017: 53.4%, 52.6-54.1 95% CI) separately. The adjusted standardised residuals showed an increase in the observed prevalence versus the expected during 2013 and 2017 for the whole sample and women and during 2017 for men. For all years, differences were observed in the SB prevalence between countries for the whole sample, and men and women separately (p < 0.001). Besides, the SB prevalence was always higher in men versus women in the overall EU sample (p < 0.001). CONCLUSIONS: SB prevalence increased between 2002 and 2017 for the EU as a whole and for both sexes separately. Additionally, differences in SB prevalence were observed for all years between EU countries in the whole sample and both sexes separately. Lastly, SB was consistently higher in men than women. These findings reveal a limited impact of current policies and interventions to tackle SB at the EU population level.

Different neuromuscular parameters influence dynamic balance in male and female football players.

PURPOSE: To analyse the relationship between several parameters of neuromuscular performance with unilateral dynamic balance measured through the Y-Balance test, as well as to determine the possible sex-related differences. METHODS: The Y-Balance test, isokinetic (concentric and eccentric) knee flexion and extension strength, isometric hip abduction and adduction strength, lower extremity joint range of motion (ROM) (hip, knee and ankle) and core stability were assessed in male (n = 88) and female (n = 44) professional football players. A stepwise multivariate linear least square regression with backward elimination analysis was carried out to identify a group of factors that were independently associated with balance performance in both sexes. RESULTS: Passive hip flexion and ankle dorsiflexion with knee flexed ROM were the main factors that retained a significant association to dominant (R2 = 23.1) and non-dominant (R2 = 33.5) balance scores for males. For females, core stability, hip abduction isometric peak torque, passive hip abduction and ankle dorsiflexion with knee flexed ROM variables retained a significant association with balance scores for both, dominant (R2 = 38.2) and non-dominant (R2 = 46.9) legs. CONCLUSIONS: Training interventions aimed at improving or maintaining unilateral dynamic balance in male football players should include, among other things, stretching exercises for the posterior chain of the lower extremity. However, females should also include exercises for strength and mobility of the hip abductors and core stability (especially in the frontal plane). This knowledge would allow clinicians and sport practitioners to develop more effective and tailored unilateral dynamic balance training interventions in male and female football players, possibly improving performance and reducing the risk of injury. LEVEL OF EVIDENCE: III.

Comparison of hip extension and rotation ranges of motion in young elite tennis players with and without history of low back pain.

BACKGROUND: Although low back pain (LBP) is known to be multi-factorial, certain studies have suggested that a deficit in hip extension and rotation range of motion (ROM) may be associated with LBP in athletes. OBJETIVE: The purpose of this study was to compare hip extension and rotation ROMs in elite tennis players with and without a history of LBP. METHODS: Forty-two male and 22 female young elite tennis players completed this study. Participants were divided into two groups: (1) 32 with history of LBP and (2) 32 without history of LBP. Descriptive measures of passive hip extension and rotation ROMs of the dominant and non-dominant limbs were taken. Active hip rotation ROMs were also assessed. Magnitude-based inferences on differences between groups and legs were made by standardizing differences. RESULTS: The inter-group statistical analysis reported no significant differences (p> 0.05; trivial effect with a probability higher than 95%; d⩽ 0.4) in any ROM measure analyzed. Further, neither LBP group nor control group reported significant bilateral or side-to-side differences (p> 0.05; trivial effect with a probability higher than 99%; d< 0.3) between legs regarding hip extension and rotation ROM measures. CONCLUSION: No relationship between hip extension and rotation ROM and history of LBP was found.

Comparisons of hip strength and countermovement jump height in elite tennis players with and without acute history of groin injuries.

BACKGROUND: Despite the high groin-injury (GI) prevalence in tennis, no studies have assessed the extent to which intrinsic groin injury risk factors, such as hip muscle strength, have recovered in elite tennis players with a history of previous GI. OBJECTIVE: To investigate whether elite tennis players with a history of GI show differences in hip strength and jump height between injured and uninjured limbs and compared with dominant limb in tennis players without history of acute groin-injuries (NGI). DESIGN: Cohort study. PARTICIPANTS: Sixty-one tennis players completed this study: 17 in the GI group and 44 in the NGI. Isometric adductor and abductor hip strength were assessed with a handheld dynamometer, and unilateral counter-movement jump tests were performed on a contact mat connected to an Ergo tester. Paired t-tests were conducted to identify differences between injured and non-injured limbs in the GI group, and independent measures t-tests were conducted to compare between GI and NGI groups. RESULTS: Isometric adductor strength and adductor/abductor strength ratios were lower in the injured limb (16.4% and 20.1%, respectively) compared with uninjured side within the GI group, and lower than the dominant side in the NGI group. No significant differences were found for unilateral jump heights between sides in the GI, nor isometric abductor strength, when comparing GI to NGI groups. CONCLUSIONS: Isometric adductor weakness and adductor/abductor strength ratio deficits suggest that adductor muscle strength is not fully recovered in these athletes, potentially increasing their risk of a repeat groin injury.