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What is the central question of this study? What is the effect of high-intensity and moderate-intensity interval running on macro- and microvascular function in a fasted state and following a glucose challenge in adolescents? What is the main finding and its importance? Both macro- and microvascular function were improved after interval running independent of intensity. This finding shows that the intermittent exercise pattern and its associated effect on shear are important for vascular benefits. In adolescents, macrovascular function was enhanced after an acute glucose load. However, the effect of chronic glucose consumption on vascular function remains to be elucidated.Interventions targeting vascular function in youth are an important strategy for the primary prevention of cardiovascular diseases. This study examined, in adolescents, the effect of high-intensity interval running (HIIR) and moderate-intensity interval running (MIIR) on vascular function in a fasted state and postprandially after a glucose challenge. Fifteen adolescents (13 male, 13.9 ± 0.6 years) completed the following conditions on separate days in a counterbalanced order: (1) 8 × 1 min HIIR interspersed with 75 s recovery; (2) distance-matched amount of 1 min MIIR interspersed with 75 s recovery; and (3) rest (CON). Macro- (flow-mediated dilatation, FMD) and microvascular (peak reactive hyperaemia, PRH) function were assessed immediately before and 90 min after exercise/rest. Participants underwent an oral glucose tolerance test (OGTT) 2 h after exercise/rest before another assessment of vascular function 90 min after the OGTT. Following exercise, both HIIR and MIIR increased FMD (P = 0.02 and P = 0.03, respectively) and PRH (P = 0.04, and P = 0.01, respectively) with no change in CON (FMD: P = 0.51; PRH: P = 0.16) and no significant differences between exercise conditions. Following the OGTT, FMD increased in CON (P 0.01) with no changes in HIIR and MIIR (both P 0.59). There was no change in PRH after the OGTT (all P 0.40). In conclusion, vascular function is improved after interval running independent of intensity in adolescents. Acute hyperglycaemia increased FMD, but prior exercise did not change vascular function after the OGTT in youth.

Purpose: In a sample of healthy adolescents, the authors aimed to investigate the effects of high-intensity interval exercise (HIIE) training and detraining on baroreflex sensitivity (BRS) and it’s vascular and autonomic components at rest. Methods: Nineteen volunteers were randomly allocated to (1) 4 weeks HIIE training performed 3 times per week or (2) a control condition with no intervention for the same duration as HIIE training. PRE, POST, and following 2 weeks of detraining resting supine heart rate and blood pressure were measured, and a cross-spectral method (integrated gain [gain in low frequency]) was used to determine BRS gain. Arterial compliance (AC) was assessed as the BRS vascular component. LFgain divided by AC (LFgain/AC) was used as the autonomic determinant of BRS. Results: The HIIE training was completed with 100% compliance. HIIE did not change resting gain in low frequency (LFgain) (P = .66; effect size = 0.21), AC (P = .44; effect size = 0.36), or LFgain/AC (P = .68; effect size = 0.19) compared to control. Conclusion: Four weeks of HIIE training does not change BRS and its autonomic and vascular determinant in a sample of healthy adolescents at rest.

This study investigated the acute post-exercise effect of high-velocity resistance exercise on ambulatory blood pressure in hypertensive older women. Fourteen volunteers (67.9±5.1 years) performed a high-velocity resistance exercise session (8 exercises using Thera-Band, 3 sets of 6 repetitions as fast as possible in the concentric phase with moderate intensity) and a control session, separated by a 7–10-day period. Ambulatory blood pressure was monitored following 12-h post-sessions and compared between conditions at 1 to 4-h, 5 to 8-h, and 9 to 12-h. Average 24-h ambulatory blood pressure, awake, asleep periods, and blood pressure load were also analyzed. There was a condition by time interaction for systolic ambulatory blood pressure over 12-h post-sessions (P=0.043). It was observed a lower systolic ambulatory blood pressure in the first 4-h period following the high-velocity resistance exercise session compared to the control session (−6.7 mmHg, 95% CI − 11.6 to −1.8 mmHg; P=0.011). No changes were observed for diastolic ambulatory blood pressure over 12-h post-sessions as well as for the other variables analyzed (P>0.05). In summary, a single high-velocity resistance exercise session elicits a post-exercise antihypertensive effect and may be considered as a strategy to acutely improve blood pressure control in hypertensive older women.

Background Ideal cardiovascular health (ICH) aims at primordial prevention of cardiovascular diseases in the population. However, there is a lack of research describing ICH in youth from middle-income countries. The aims of this study were to describe the prevalence of ICH at 18- and 22-year-old and to investigate the influence of socioeconomic status. Methods The sample consisted of participants from the Pelotas 1993 birth-cohort followed-up at 18- (n = 4,106) and 22-year-old (n = 3,810). Ideal metrics were created for diet, smoking, body mass index, physical activity, blood pressure, total cholesterol, and blood glucose. The presence of 4 or more ideal metrics was defined as ICH. Socioeconomic status was obtained using wealth quintiles calculated with factor analysis based on analysis based on the ownership of household and education. The impact of socioeconomic status on ICH metrics was statistically measured using the slope index of inequality. Results The prevalence of ICH was 84.5% (95% confidence interval [CI] = 82.7-86.2%) and 84.1% (82.3-85.8%) at 18-year-old and decreased to 61.1% (58.4-63.7%) and 68.7% (66.2-71.2%) at 22-years old, for male and female, respectively. Socioeconomic status influenced ICH and its components differently in males and females. Wealthiest females had ICH prevalence 19 percentage points (pp) (11-27 pp) higher compared to the poorest, whereas poorest males had ICH prevalence 12 pp (1-21 pp) higher compared to the wealthiest. Longitudinal decreases in ICH components were mostly present in the poorest females. Conclusions In middle-income countries, the prevalence of ICH is high at 18-year-old and decreases in a 4-year follow-up. Socioeconomic status influences differently individuals’ ICH between sexes. Efforts are needed to maintain ICH in youth and different strategies may be required between the social status.

Improvements in the autonomic and vascular systems are implicated in cardiovascular disease risk reduction. Baroreflex sensitivity (BRS) is composed of vascular and autonomic components. This study aimed to investigate between- and within-day reliability of BRS and its autonomic and vascular determinants in adolescents. Thirteen male adolescents (14·1 ± 0·5 y) participated in this study. For between-day reliability, participants completed four experimental visits separated by a minimum of 48-h. For within-day reliability, participants repeated BRS assessments three times in the morning with one hour between the measures. BRS was evaluated using the cross-spectral gain (LFgain) between blood pressure and heart rate interval. BRS was further divided into: 1) vascular component using arterial compliance (AC); and 2) autonomic component measured as LFgain divided by AC (LFgain/AC). LFgain, AC and LFgain/AC presented between-day coefficient of variation (CV) of 20%, 17%, and 20%, respectively. Similarly, variables associated with blood pressure control, such as cardiac output, mean arterial pressure, heart rate and total peripheral resistance, presented CVs ranging from 6% to 15%. Within-day reliability was poorer compared to between-day for LFgain (25%), AC (25%), and LFgain/AC (31%), as well as all hemodynamic variables (CVs from 11% to 22%, except heart rate with presented CV of 6%). This study indicates suitable between- and within-reliability of BRS and its autonomic and vascular determinants, as well as hemodynamic variables associated with BRS, in adolescents.

Background Heart rate variability (HRV) is considered to explain improvements in cardiovascular health accrued by physical activity (PA) and cardiorespiratory fitness (CRF) over and above traditional cardiovascular risk factors. Objective To systematically address associations between HRV, PA and CRF in children and adolescents. Data sources Medline, EMBASE, SportDISCUS and CINAHL Plus were searched on 5th September 2015 and updated on 4th August 2016. Eligibility criteria Observational studies comparing HRV in different groups of PA and CRF, and/or studies investigating associations between PA, CRF and HRV. Sports practices and PA intensities were also included. The square root of the mean of the sum of the squares of differences between adjacent RR intervals (RMSSD), the spectral density in the high (HF) and low (LF) frequency, and the LF/HF ratio were included. Risk of bias was assessed using the adapted Newcastle-Ottawa Scale (NOS). Results Heterogeneity exists in the assessment of the exposures and outcomes, and sample characteristics. Risk of bias (NOS) was observed in most of the studies. Studies with low risk of bias showed positive associations between moderate-to-vigorous PA and RMSSD. The evidence for the associations between PA and frequency indices is weak. Similarly, the evidence for the association between CRF and HRV is weak. Conclusions Despite the heterogeneity in the studies, moderate-to-vigorous PA is positively associated with RMSSD, but less clear are the associations between CRF and HRV, as well as other PA intensities. Further research is needed to clarify the role of PA and CRF on HRV in children and adolescents.

The aim of this study was to synthesize the evidence on the effects of active video games (AVGs) on mental health, physical fitness and body composition of children and adolescents. A search was conducted in the following databases: PubMed; MEDLINE (by Ovid); SportDiscus, Cochrane library systematic reviews (CENTRAL) and EMBASE with no language restrictions during October 2020. Reviews on the use of AVGs were included in the study. We use the AMSTAR (A MeaSurement Tool to Assess systematic Reviews) scale to analyze the methodological quality of the studies. Seventeen systematic reviews and meta-analyzes were included on the effects of AVGs with 30 to 4728 children and adolescents of both sexes with ages ranging from 6 to 19 years. In five studies, the population was overweight or obese. Regarding the quality, 12 studies were of moderate quality, two had high quality, two had low quality and one showed very low quality. The analyzed data indicate that the use of AVGs with a frequency of 1 to 3 times a week with durations of between 10 and 90 min per day shows positive effects on mental health and physical functioning. There was moderate quality evidence that AVGs can result in benefits for self-esteem, increased energy expenditure, physical activity and reduced body mass index in children and adolescents who used AVGs in the home environment. Further research is needed on this tool to help in the process of social isolation and consequently in promoting health and well-being.

What is the central question of this study? What are the autonomic and vascular components of the baroreflex during hypotension following different exercise intensities in adolescents? What is the main finding and its importance? Hypotension after high-intensity exercise lasted 60 min, whereas following moderate-intensity exercise, blood pressure was restored after 20 min. Stroke volume and peripheral resistance responses were different between intensities. Post both exercise intensities, baroreflex sensitivity was lowered mainly due to the autonomic component, which returned to baseline 60 min post-exercise. The different haemodynamic stimuli indicate potential differences in cardiovascular health benefits of exercise intensity in healthy adolescents.This work aimed to investigate the time course of changes in baroreflex sensitivity (BRS) and its vascular and autonomic components after different exercise intensities in adolescents. Thirteen male adolescents (age 13.9 ± 0.5 years) completed on separate days in a counterbalanced order (1) high-intensity interval exercise (HIIE): 8 × 1 min running at 90% of maximal aerobic speed with 75 s of active recovery; (2) moderate-intensity interval exercise (MIIE): 10-12 bouts of 1 min running at 90% of gas exchange threshold with 75 s of active recovery; and (3) resting as a control. Supine heart rate and blood pressure were monitored continuously at baseline, and 5 and 60 min following the conditions. A cross-spectral method (low frequency gain; LF

The aims of this study were to investigate in adolescents: 1) the relationships of physical activity (PA) and cardiorespiratory fitness (CRF) to traditional CVD risk factors, rest and recovery autonomic function; and 2) whether autonomic function strengthens the associations between PA, CRF and CVD risk. Fifty-four (22 girls) adolescents had traditional CVD risk factors, rest and recovery autonomic function evaluated. CRF was measured using a steep ramp cycle test and PA was assessed with accelerometers. Resting HRV (and RMSSD30) and heart rate recovery (T30, HHRτ) were used. Clustered traditional (CVDRtrad) and autonomic (CVDRauto) risk scores were created and added to form a composite clustered CVD risk score (CVDRcom). PA and CRF were significantly and negatively associated with traditional CVD risk factors. Moderate (MPA) and vigorous (VPA) were positively related to resting RMSSD, and negatively related to T30 and HHRτ (all P

The analysis of post-exercise cardiac autonomic recovery is a practical clinical tool for the assessment of cardiovascular health. A reduced heart rate recovery - an indicator of autonomic dysfunction - has been found in a broad range of cardiovascular diseases and has been associated with increased risks of both cardiac and all-cause mortality. For this reason, over the last several years, non-invasive methods for the assessment of cardiac autonomic recovery after exercise - either based on heart rate recovery or heart rate variability indices - have been proposed. However, for the proper implementation of such methods in daily clinical practice, the discussion of their clinical validity, physiologic meaning, mathematical formulation and reproducibility should be better addressed. Therefore, the aim of this methodological review is to present some of the most employed methods of post-exercise cardiac autonomic recovery in the literature and comprehensively discuss their strengths and weaknesses.