Does exercise intensity affect blood pressure and heart rate in obese adolescents? A 6-month multidisciplinary randomized intervention study

Effects of different types of exercise intensity on improving health-related physical fitness in children and adolescents: a systematic review

A substantial body of empirical evidence reveals that physical activity is associated with a wide range of positive physical and mental health outcomes. However, an absence of comprehensive syntheses is observed concerning the varying effects of different exercise intensities on the improvement of physical health among children and adolescents. The aim of this review is to systematically investigate the effects of different exercise intensities on the physical fitness of children and adolescents, to analyses the optimal exercise intensities for improving physical fitness, and to provide a relevant theoretical basis for optimizing school physical education curricula. A systematic search strategy was used in this study in four online databases (PubMed, Scopus, EBSCO and Web of Science). Intervention studies that met the inclusion criteria underwent a thorough screening process, and their methodological quality was assessed utilizing the PEDro scale. The selected literature was systematically analyzed and evaluated through induction, summary, analysis, and evaluation. These findings indicate that high-intensity exercise training exerts significant positive effects on body composition, cardiopulmonary function and muscle fitness in children and adolescents. Therefore, we suggest that schools should focus on high-intensity sports in their physical education curriculum, which can further improve the student's PHYSICAL FITNESS.

Effects of School-Based High-Intensity Interval Training on Hemodynamic Parameters and Heart Rate Variability: A Randomized Controlled Trial

ABSTRACT

Ketelhut, S, Ketelhut, K, Ketelhut, SR, and Ketelhut, RG. Effects of school-based high-intensity interval training on hemodynamic parameters and heart rate variability: A randomized controlled trial. J Strength Cond Res 38(6): 1033-1040, 2024-The purpose of this study was to assess the effects of a child-specific school-based high-intensity interval training (HIIT) implemented into physical education (PE) classes on various hemodynamic parameters and heart rate variability indices. Forty-six students (age 11 ± 1 year) were randomized into an intervention (INT n = 22) and a control group (CON n = 24). During a 12-week period, the INT and CON groups participated in regular PE twice weekly (45-90 minutes). The INT group received HIIT during the first 20 minutes of the 2 PE classes. Systolic and diastolic blood pressure, total peripheral resistance, aortic pulse wave velocity (aPWV), heart rate, SD of normal to normal heartbeat intervals, the root mean square of successive differences between normal heartbeats (RMSSD), the proportion of differences between adjacent normal to normal heartbeat intervals of more than 50 ms, low-frequency power, high-frequency power, and the LF/HF ratio were assessed before and after the experimental period. A p value ≤0.05 was considered statistically significant. Forty students (20 INT; 20 CON) were included in the analysis. A significant time × group interaction was detected for aPWV ( p = 0.05, η2 = 0.099), RMSSD ( p = 0.010, η2 = 0.161), low-frequency power ( p = 0.009, η2 = 0.165), high-frequency power ( p < 0.001, η2 = 0.272), and the LF/HF ratio ( p < 0.001, η2 = 0.354). The INT group revealed significant improvements for the respective parameters. School-based HIIT can induce improvements in cardiovascular parameters. These results highlight the potential of embedding HIIT within the school setting, offering a time-efficient exercise intervention.

Short-Term High-Intensity Rowing Ergometry Training Improves Rowing Performance Equally in Healthy Weight and Obese Adolescents

PURPOSE

Childhood obesity is a major health concern and physical activity is commonly proposed as an intervention strategy to combat the increasing prevalence of overweight and obesity in young people. The aim of this study was to examine the effect of high-intensity, supervised, rowing ergometer training on maximal and submaximal rowing performance in healthy weight and centrally obese adolescents (12-13 yr).

METHODS

Participants were randomized to either 6 wk of supervised rowing ergometry, comprising of 2 sessions per week with each session comprising of 2 × 3-min bouts of high-intensity rowing ergometry ( n = 57), or a control group who continued with their habitual activities ( n = 45). At baseline and follow-up, rowing performance was assessed via a submaximal test and a 3-min maximal test.

RESULTS

Six weeks of rowing ergometer training significantly improved maximal exercise performance; total distance rowed in a 3-min maximal effort improved by 19.7 m (2.7%) (time × group, P = 0.018) and produced a significant reduction in perceived effort in response to a set submaximal load (60 W) (time × group, P = 0.040). At baseline total distance rowed during the 3-min maximal test was significantly affected by body mass (main effect of body mass, P = 0.002), whereby a higher body mass was associated with enhanced rowing performance. However, the pattern of change over time was not different between healthy weight and centrally obese adolescents (time × group × waist centile, P = 0.577).

CONCLUSIONS

A 6-wk high-intensity rowing ergometry training intervention improved maximal rowing performance. This improvement was similar in healthy weight versus overweight and obese adolescents; yet overall overweight and obese adolescents had superior rowing performance compared to their healthy weight counterparts, suggesting that rowing may be an attractive exercise modality for interventions in overweight and obese young people.

Dose-effect of exercise intervention on heart rate variability of acclimatized young male lowlanders at 3,680 m

This study investigated whether exercise could improve the reduced HRV in an environment of high altitude. A total of 97 young, healthy male lowlanders living at 3,680 m for >1 year were recruited. They were randomized into four groups, of which three performed-low-, moderate-, and high-intensity (LI, MI, HI) aerobic exercise for 4 weeks, respectively. The remaining was the control group (CG) receiving no intervention. For HI, compared to other groups, heart rate (p = 0.002) was significantly decreased, while standard deviation of RR intervals (p < 0.001), SD2 of Poincaré plot (p = 0.046) and the number of successive RR interval pairs that differ by > 50 ms divided by total number of RR (p = 0.032), were significantly increased after intervention. For MI, significantly increase of trigonometric interpolation in NN interval (p = 0.016) was observed after exercise. Further, a decrease in systolic blood pressure (SBP) after high-intensity exercise was found significantly associated with an increase in SD2 (r = - 0.428, p = 0.042). These results indicated that there was a dose effect of different intensities of aerobic exercise on the HRV of acclimatized lowlanders. Moderate and high-intensity aerobic exercise would change the status of the autonomic nervous system (ANS) and decrease the blood pressure of acclimatized lowlanders exposed to high altitude.

Effect of high-intensity interval training and moderate-intensity continuous training on cardiovascular risk factors in adolescents: Systematic review and meta-analysis of randomized controlled trials

BACKGROUND

In recent years, cardiovascular diseases in adolescents have become more serious. High intensity interval training (HIIT) and moderate intensity continuous training (MICT) have been shown to improve cardiovascular diseases in adolescents. Meta-analysis was conducted to compare the effects of HIIT and MICT on cardiovascular risk factors in adolescents.

METHODS

Randomised controlled trials of HIIT and MICT for cardiovascular risk factors in adolescents up to January 2023 were searched using authoritative databases such as CNKI, Web of Science, PubMed, and EBSCO. Data analysis was performed using Review Manage 5.4 and Stata 14.0.

RESULTS

A total of 12 studies involving 468 participants, mean age 15.19±4.35, were included in the study. The findings showed that compared with MICT, HIIT reduced adolescents' body weight (SMD=-0.18, 95 %CI=-0.58, 0.21) and increased maximal oxygen uptake (SMD=0.56, 95 %CI=0.20, 0.93) and high-density lipoprotein (SMD=-0.47, 95 % CI=-1.11, 0.17), and improved systolic blood pressure (SMD=-0.35, 95 %CI=-0.78, 0.09), glucose (SMD=-1.53, 95 %CI=-2.93, -0.13), and insulin (SMD=-0.66, 95 % CI=-1.73, 0.41), p<0.05. HIIT and MICT improved BMI, fat mass, diastolic blood pressure, triglycerides, total cholesterol, and LDL, with no significant difference between these training types.

CONCLUSION

HIIT was better than MICT for improving cardiovascular health in adolescents, with better effects on body weight, BMI, fat mass, systolic blood pressure, diastolic blood pressure, maximal oxygen uptake, triglyceride, total cholesterol, LDL, HDL, glucose, and insulin levels.

Effect of high-intensity interval training on cardiorespiratory in children and adolescents with overweight or obesity: a meta-analysis of randomized controlled trials

Objective

This meta-analysis aimed to examine the effect of high-intensity interval training on cardiorespiratory fitness in children and adolescents with overweight or obesity, and to explore the optimal dose of high-intensity interval training to improve cardiorespiratory fitness in children and adolescents with overweight or obesity.

Methods

Randomized controlled trials on the effects of HIIT on cardiorespiratory fitness in children and adolescents with overweight or obesity were retrieved from six electronic databases, including PubMed, Web of Science, Cochrane Library, CNKI, Wanfang, and VIP. The quality assessment of the included studies was conducted following the revised quality evaluation method based on the PRISMA principles. Keywords for literature search mainly include high-intensity interval, cardiorespiratory fitness, overweight, obese, children, and adolescent, etc.

Results

(1) A total of 18 studies, comprising 581 participants (288 in the intervention group and 293 in the control group), were included and all of them were of moderate to high quality. (2) HIIT had a positive effect on the cardiorespiratory fitness levels of in children and adolescents with overweight or obesity (SMD = 0.91; 95% CI: 0.66, 1.15; p < 0.00001). (3) The improvement in cardiorespiratory fitness was more significant when the HIIT intervention lasted for more than 10 weeks (SMD = 1.04; 95% CI: 0.74, 1.34; p < 0.00001), was conducted 3 times per week, with 2 to 8 sets per session (SMD = 1.13; 95% CI: 0.71, 1.55; p < 0.00001), and maintained a ratio of approximately 1:1 between exercise and rest intervals (SMD = 1.11; 95% CI: 0.73, 1.50; p < 0.00001).

Conclusion and recommendations

(1) Long-term HIIT can improve cardiorespiratory fitness in children and adolescents with overweight or obesity. (2) To achieve significant improvements in cardiorespiratory fitness in a short period, children and adolescents with overweight or obesity can engage in HIIT programs lasting for more than 10 weeks, conducted 3 times per week, with 2 to 8 sets per session, and a ratio of approximately 1:1 between exercise and rest intervals.

Systematic Review Registration

Identifier: INPLASY202350033.

Executive function elevated by long term high-intensity physical activity and the regulation role of beta-band activity in human frontal region

The importance of physical activity (PA) to people's health has become a consensus around the world, and regular long-term PA has been accepted as an alternative preventive measure for many chronic medical conditions. Although the daily PA have several benefits for the public, the systematic research on its effect in human physiology, cognition and cerebral nerve level is not fully studied. Hence, in this study, we aim to investigate this question in several specific aspects: basal heart rate, executive function, and neural oscillatory activity in the brain. A total of 146 subjects participated in this study and they were divided into two groups. One group (SG) is the long-term training (more than 8 years) subjects in soccer (n = 31), and the other group (CG) is a normal control group (n = 115). The heart rate was monitored with a portable equipment. Besides, 24 subjects (14 in SG and 10 in CG) participated the Go/No-Go task and EEG recording before and after exercise fatigue task. In the physiology level, we found that in the non-training time, the heart rate in CG group is significantly higher than that of the SG group (P < 0.001). In the cognition level, we found that the SG group has a faster reaction time that that of CG group (P < 0.01), while for the accuracy, two groups did show significant difference. In the neural level in the brain, we found a significant abnormal increased beta-band (around 25 Hz) activity in CG group after the exercise fatigue task immediately. Long-term high-intensity physical activity reduces basal heart rate, improves executive function, and improve the central tolerance of the body under the stimulation of fatigue and stress. These benefits of long-term activity could be used as a manual to guide people's healthy life.

School-based high-intensity interval exercise program in children with overweight induce a greater improvements in body composition and physical fitness than moderate-intensity continuous exercise

BACKGROUND

High-intensity interval running exercise (HIIE) is emerging as a time-efficient exercise modality for improving body composition and fitness in comparison with moderate-intensity continuous aerobic exercise (MICE); however, existing evidence is still unclear in children with overweight and thus we compared the effects of HIIE and MICE on body composition, muscular, and cardiorespiratory fitness in children with overweight.

METHODS

In this randomized study, 40 male children with overweight aged 7-10 years were divided into an 8-week exercise regime: (1) HIIE group [n = 20; 2 sets of 15 × 20s at 85-95% maximal aerobic speed (MAS) separated by 15 × 20s recovery at 50% MAS, 3 days per week] and (2) MICE group [n = 20; 30 min at 60-70% MAS, 3 days per week]. Body composition, muscular and cardiorespiratory fitness were assessed before and after the 8-week intervention at similar times and conditions of the day.

RESULTS

Following the 8-week HIIE protocol, weight, BMI, and fat mass decreased significantly (weight: - 1.4% vs. 0.2%, p < 0.05; BMI: - 3.1% vs. - 0.7%, p < 0.05; fat mass: - 7.7% vs. - 1.6%, p < 0.01) as compared with MICE; while the VO2peak and MAS increased significantly in both groups, the increase in HIIE group was significantly greater than that of MICE group (VO2peak: 10.3% vs. 3.5%, p < 0.01; MAS:7.7% vs. 4.5%, p < 0.05). Although significant improvements in muscular fitness were observed in HIIE and MICE groups [counter movement jump (CMJ): 7.8% vs. 5.4%; sprinting ability: - 3.7% vs. - 1.7%], no significant differences were seen between them (p > 0.05).

CONCLUSION

Our findings suggested that school-based HIIE intervention was highly in improving body composition and cardiorespiratory fitness of children with overweight than the MICE regime; however, MICE still provided improvements over time that were just not to the same magnitude of HIIE.

Physical activity interventions for cardiopulmonary fitness in obese children and adolescents: a systematic review and meta-analysis

PURPOSE

This study [PROSPERO CRD42023416272] systematically analysed the effects of a physical activity intervention on cardiorespiratory fitness in obese children and adolescents and elucidated the factors that influenced those effects.

METHODS

A systematic review of the literature on physical activity interventions for improving cardiopulmonary fitness in obese children and adolescents from January 1, 2011, to March 1, 2023, was conducted. The search was performed on the Web of Science and PubMed databases, and the selected literature was first screened and then assessed for quality. Finally, a systematic review was conducted.

RESULTS

Out of the initially identified 1424 search records, 28 studies were eventually included in the systematic review. These studies encompassed a total of 2724 participants aged 5 to 18 years, with the publication dates of the literature primarily ranging from 2011 to 2023. Physical activity was found to effectively improve the following parameters in obese children and adolescents: weight [mean difference (MD), -2.03 (95% confidence interval, -2.59 to -1.47), p < 0.00001], maximal oxygen consumption [MD, -1.95 (95% CI, -1.06 to -2.84), p < 0.0001], heart rate [MD, -2.77 (95% CI, -4.88 to -0.67), p = 0.010], systolic blood pressure [MD, -8.11 (95% CI, -11.41 to -4.81), p < 0.00001], and diastolic blood pressure [MD, -4.18 (95% CI, -5.32 to -3.03), p < 0.00001]. High-intensity exercise was found to yield greater improvements than low- to moderate-intensity exercise in maximal oxygen consumption [MD, 1.43 (95% CI, 0.04 to 2.82), p = 0.04] and diastolic blood pressure [MD, -6.94 (95% CI, -10.61 to -3.26), p = 0.0002] in obese children and adolescents.

CONCLUSION

Physical activity can effectively improve the body weight, maximal oxygen consumption, heart rate, systolic blood pressure, and diastolic blood pressure of obese children and adolescents. The type of physical activity directly influences the participation interest of obese children and adolescents, with moderate- to high-intensity physical activity showing the most significant impact on intervention outcomes. High-frequency, long-term interventions yield better results than short-term interventions.

Minimal Detectable Change in Resting Blood Pressure and Cardiorespiratory Fitness: A Secondary Analysis of a Study on School-Based High-Intensity Interval Training Intervention

High-intensity interval training (HIIT) effects on resting blood pressure (BP) and cardiorespiratory fitness (CRF) have already been studied. Furthermore, the responses of responders and non-responders to HIIT in terms of these physiological outcomes have also been examined. However, the minimal detectable change (MDC) in BP and CRF has not been addressed yet. Therefore, the current study aimed to compare the MDC90 of BP (systolic and diastolic) and CRF (fitness index (FI) results) in the context of a school-based HIIT program for adolescents. Participants were adolescents, with an average age of 16.16 years (n = 141; 36.6% males). A preplanned secondary analysis was conducted using pre-post data from the control group to estimate MDC90. The MDC90 of SBP, DBP, and FI were 7.82 mm HG, 12.45 mm HG, and 5.39 points, respectively. However, taking into account the relative values of these changes, MDC90 required a greater change in DBP (17.27%) than FI (12.15%) and SBP (6.68%). Any training-induced physiological changes in the average values of the outcomes did not exceed MDC90. However, a comparison of the participants who exceeded and did not exceed MDC90 showed statistically significant differences. These findings reveal the huge variability in and insensitivity to the intervention effect for all measurements. This is likely because of the large subgroup of participants with low sensitivity to the physiological stimulus. As such, there is a considerable need to create individually tailored intervention programs.

The Effects of Obesity on the Inflammatory, Cardiovascular, and Neurobiological Responses to Exercise in Older Adults

Obesity with advancing age leads to increased health complications that are involved in various complex physiological processes. For example, inflammation is a critical cardiovascular disease risk factor that plays a role in the stages of atherosclerosis in both aging and obesity. Obesity can also induce profound changes to the neural circuitry that regulates food intake and energy homeostasis with advancing age. Here we discuss how obesity in older adults impacts inflammatory, cardiovascular, and neurobiological functions with an emphasis on how exercise mediates each topic. Although obesity is a reversible disorder through lifestyle changes, it is important to note that early interventions are crucial to prevent pathological changes seen in the aging obese population. Lifestyle modifications such as physical activity (including aerobic and resistance training) should be considered as a main intervention to minimize the synergistic effect of obesity on age-related conditions, such as cerebrovascular disease.

Prognostic Potential of the Body Composition Indices in Predicting Positive Changes in Resting Blood Pressure after High-Intensity Interval Training in Adolescents

This study aimed to investigate the prognostic potential of body composition indices in predicting the improvement in resting blood pressure after 10 weeks of high-intensity interval training (HIIT) implemented in physical education lessons. The participants were 141 adolescents aged 16 years. Independent variables were body mass index (BMI), fat mass index (FMI), muscle mass index (SMI), and mass to fat ratio (MFR); dependent variables were systolic and diastolic blood pressure (SBP, DBP) and its indices: pulse pressure (PP), mid-blood pressure (MBP), and mean arterial pressure (MAP). The receiver operating curve (ROC) method was employed. SMI and MFR are body composition indices with prognostic potential to predict positive changes in SBP in males (SMI: AUC = 0.82; p < 0.001, MFR = 0.70; p = 0.039) and MFR in females (AUC = 0.72; p = 0.035). The respective cut-off point values used to classify participants as a beneficiary of HIIT intervention concerning SBP were SMI = 7.84 and MFR = 2.43 in males, and for SMI = 10.12 and MFR = 1.94 in females. Body composition indices based on skeletal muscle (SMI, MFR) were more likely to predict positive changes in SBP after HIIT intervention in adolescents. PP, MBP, and MAP did not reflect the detecting power of SMI and MFR. However, these thresholds' utility is limited to adolescents of 16 years of age.

The Role of Adiposity in the Association Between Physical Activity and Blood Pressure in Children

Purpose: To analyze whether body adiposity mediates and/or moderates the association between time in moderate-to-vigorous physical activities (MVPA) and blood pressure in children. Methods: This was a cross-sectional study of 577 children aged 5 to 7 years old. MVPA was measured by accelerometry. Body mass index (BMI), waist circumference (WC), and the sum of tricipital and subscapular skinfolds (skinfolds) assessed children's body adiposity. Systolic (SBP) and diastolic blood pressure (DBP) were used as the dependent variables. Results: In the primary analysis adjusting for BMI or skinfolds measures, additional time in MVPA was associated with higher SBP. On the other hand, further analyses showed that children in the largest BMI tertile (β_SBP:0.18; 95%CI: 0.12-0.24; β_DBP:0.11; 95%CI: 0.05-0.17), waist circumference (β_SBP:0.16; CI: 0.09-0.22; β_DBP:0.08; CI:0.02-0.14), or sum of skinfolds (β_SBP:0.18; CI: 0.11-0.24; β_DBP:0.09; CI: 0.03-0.16) presented a positive relationship between MVPA and blood pressure whereas no positive association was observed for children in the first and second adiposity tertiles. Adiposity also mediated the association between MVPA and blood pressure. A decrease of 0.03 mmHg in the systolic blood pressure was observed by decreasing the sum of skinfolds for each additional minute per day in MVPA. A decrease in diastolic blood pressure of 0.02 mmHg was observed for each additional minute per day in MVPA, which was related to a negative association between time in MVPA and waist circumference and sum of skinfolds. Conclusion: Not accounting for the potential moderation and mediation role of adiposity may lead to misinterpretations in the MVPA and blood pressure relationship.

Effects of High-Intensity Interval Training in School on the Physical Performance and Health of Children and Adolescents: A Systematic Review with Meta-Analysis

Background

Performance of high-intensity interval training (HIIT) by children and adolescents improves physical and health-related fitness, as well as cardiometabolic risk factors.

Objectives

To assess the impact of HIIT performed at school, i.e. both in connection with physical education (intra-PE) and extracurricular sports activities (extra-PE), on the physical fitness and health of children and adolescents.

Methods

PubMed and SPORTDiscus were searched systematically utilizing the following criteria for inclusion: (1) healthy children and adolescents (5–18 years old) of normal weight; (2) HIIT performed intra- and/or extra-PE for at least 5 days at an intensity ≥ 80% of maximal heart rate (HR_max) or peak oxygen uptake (VO_2peak) or as Functional HIIT; (3) comparison with a control (HIIT versus alternative interventions); and (4) pre- and post-analysis of parameters related to physical fitness and health. The outcomes with HIIT and the control interventions were compared utilizing Hedges’ g effect size (ES) and associated 95% confidence intervals.

Results

Eleven studies involving 707 participants who performed intra-PE and 388 participants extra-PE HIIT were included. In comparison with the control interventions, intra-PE HIIT improved mean ES for neuromuscular and anaerobic performance (ES jump performance: 5.89 ± 5.67 (range 1.88–9.90); ES number of push-ups: 6.22 (range n.a.); ES number of sit-ups: 2.66 ± 2.02 (range 1.24–4.09)), as well as ES fasting glucose levels (− 2.68 (range n.a.)) more effectively, with large effect sizes. Extra-PE HIIT improved mean ES for neuromuscular and anaerobic performance (ES jump performance: 1.81 (range n.a.); ES number of sit-ups: 2.60 (range n.a.)) to an even greater extent, again with large effect sizes. Neither form of HIIT was more beneficial for parameters related to cardiorespiratory fitness than the control interventions.

Conclusion

Compared to other forms of exercise (e.g. low-to-moderate-intensity running or walking), both intra- and extra-PE HIIT result in greater improvements in neuromuscular and anaerobic performance, as well as in fasting levels of glucose in school children.

Development of an Extended-Reality (XR)-Based Intervention to Treat Adolescent Obesity

Public health policies aimed at obesity reduction are more often directed toward adults than children. This is alarming given that rates of childhood obesity have been steadily increasing, and, if not treated early, adolescents with obesity may develop comorbidities into adulthood. Lifestyle-based interventions are the cornerstone of childhood obesity treatment. Recently, extended-reality (XR)-based interventions have been incorporated into the treatment of obesity, and parents and adolescents perceive virtual reality (VR) interventions as a promising approach to increasing physical activity levels and improving eating habits. VR is a tool that fits perfectly with contemporary adolescent culture, which is radically different from that of just two generations ago. It is plausible that an XR-based intervention for treating adolescents with obesity could have a profound influence on obesity management over the long-term. An understanding of adolescents’ preferences, wants, and needs must be considered in the development of new interventions. We suggest that VR interventions can provide a new approach to weight management for children and adolescents and provide recommendations to assess adolescents’, caregivers’, and primary care providers’ needs. These needs could then be used for the development of an XR-based intervention aimed at inducing sustained lifestyle changes in adolescents with obesity.

Prevalence of Positive Effects on Body Fat Percentage, Cardiovascular Parameters, and Cardiorespiratory Fitness after 10-Week High-Intensity Interval Training in Adolescents

Simple Summary

In this study, we aimed to analyze the prevalence of positive effects of high-intensity interval training (HIIT) on body composition, cardiovascular parameters, and cardiorespiratory fitness among adolescents. We investigated 52 boys and 89 girls from a secondary school, separated into an experimental group (EG) with HIIT intervention and a control group (CG). The measured parameters were body fat % (BFP), resting systolic blood pressure (SBP), diastolic blood pressure (DBP), and fitness index (FI). The results indicate that positive HIIT-induced changes in SBP, DBP, and FI were most common among boys, especially those with low body mass index. Our study also revealed relationships between changes in FI and BFP and BP parameters. The effectiveness of HIIT was confirmed concerning the prevalence of the positive changes in measured parameters. We suggest that HIIT should be implemented in PE lessons, although there is a need to look for a more efficient method for girls.

Abstract

Analysis of the interventions on cardiovascular disease risk factors focuses on quantitative changes, omitting assessment of positive effect frequency in individuals. The aim of this study was to assess the prevalence of positive effects of high-intensity interval training (HIIT) on body composition, cardiovascular parameters, and cardiorespiratory fitness among adolescents. A total of 52 boys and 89 girls from a secondary school were separated into an experimental group (EG) with HIIT and a control group (CG). Body fat % (BFP), resting systolic blood pressure (SBP), diastolic blood pressure (DBP), and fitness index (FI) changes were calculated. We assessed the influence and interaction of three factors: intervention (INT), sex (SEX), and body mass index (BMI_status) on the ratio of individuals with and without positive changes. We used log-linear models for interactions and multivariate correspondence analysis (MCA). The results indicate that HIIT affects the prevalence of positive changes in SBP, DBP, and FI. Interactions between factors suggest boys with low BMI get more benefit from the intervention than girls. The MCA indicates a relationship between FI and BFP and between BP parameters. The effectiveness of HIIT was confirmed concerning the prevalence of the positive changes in measured parameters. We suggest that HIIT should be implemented in PE lessons, although there is a need to look for a more efficient method for girls.

The high-intensity interval training introduced in physical education lessons decrease systole in high blood pressure adolescents

Increased resting blood pressure (BP) is a risk factor for many health complications. The prevalence of elevated BP is growing among adolescents. There is a need to investigate effective ways of decreasing excessive blood pressure in this age group. The study aim was to determine the effect of 10-weeks High-Intensive Interval Training (HIIT)—Tabata protocol—introduced in physical education (PE) lessons on resting blood pressure in adolescents. The sample included 52 boys aged 16.23 ± 0.33 years body height176.74 ± 6.07 (m), body weight 65.42 ± 12.51 (kg), BMI 20.89 ± 3.53 (kg/m²) and 89 girls aged 16.12 ± 0.42 years, body height 164.38 ± 6.54 (m), body weight 56.71 ± 10.23 (kg), BMI 20.93 ± 3.08 (kg/m²) from secondary school. Based on resting BP, the fractions of boys and girls with normal BP and high BP were identified and divided into experimental (EG) and control (CG) groups. EG completed a 10-weeks HIIT program (three cycles of Tabata protocol) implemented in one PE lesson during a week. The duration of the effort was 14 min. The intensity was at 75–80% of maximal heart rate. Changes in systolic and diastolic BP after the experiment were examined. The results indicated the improvement in SBP in EG with high BP compared to the rest of the groups (average reduction of 12.77 mmHg; p < 0.0001). The EG normotensive had a statistically significant higher reduction of SBP comparing CG normotensive (average decrease of 1.81 mmHG; p = 0.0089). HIIT effectively decreases BP in adolescents. Implementing HIIT in PE lessons in secondary school is recommended to improve BP parameters.

Effects of Physical Training on Heart Rate Variability in Children and Adolescents with Chronic Diseases: A Systematic Review and Meta-analysis

This study analyzed the effects of physical training programs on heart rate variability, as a measure of sympathovagal balance, in children and adolescents with chronic diseases. Relevant articles were systematically searched in Pubmed, Science Direct, Web of Science, Scopus, Google Scholar and Embase scientific databases. We performed a meta-analysis using an inverse variance heterogeneity model. Effect size calculation was based on the standardized mean differences between pre- and post-intervention assessments, assuring at least a single-group repeated-measures model for each extracted group. Ten studies (252 participants) were included, seven in obese subjects, two in type-1 diabetes, and one in cerebral palsy. When time-domain variables were analyzed, exercise was found to moderately increase RMSSD (SMD=0.478; 95%CI: 0.227 to 0.729; p<0.001), SDNN (SMD=0.367; 95%CI: 0.139 to 0.595; p=0.002) and pNN50 (SMD=0.817; 95%CI: 0.139 to 0.595; p=0.002). As for frequency-domain variables, exercise presented a moderate increasing effect on HF (SMD=0.512; 95%CI: 0.240 to 0.783; p<0.001), a negligible effect for LF (SMD=0.077; 95%CI: -0.259 to 0.412; p<0.001) and a non-significant reduction for LF/HF (SMD=-0.519; 95%CI: -1.162 to 0.124; p=0.114). In conclusion, physical training programs are able to modulate heart rate variability in children and adolescents with chronic diseases, affecting mainly the time-domain variables.

Relationship between heart rate variability and body mass index: A cross-sectional study of preschool children

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Heart rate variability and BMI are inversely related in preschool children.

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One unit increase in BMI resulted in a reduction in RMSSD(ln) of 0.06%

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Age, sex and physical activity levels did not influence this relationship.

Reduced heart rate variability (HRV) is associated with overweight and obesity in adults. However, little is known about this relationship in early childhood. We investigated the relationship between resting vagally-mediated HRV and body mass index (BMI) in Australian preschool children. Children were recruited from 13 non-government early learning centres located in Queensland and New South Wales, Australia. From this population-based sample, data from 146 healthy children (58 females) between 3 and 5 years of age (mean age 4.35 ± 0.44 years) were analysed. BMI was calculated from child body weight and height. Physical activity was recorded using an Actigraph wGT3x accelerometer worn at the waist of participants over 3 consecutive days. A Polar H10 chest strap measured seated, resting RR intervals for the calculation of HRV with the root mean square of successive differences (RMSSD) reflecting vagally-mediated activity. The relationship between HRV and BMI was analysed using a linear mixed model adjusted for age, sex and physical activity. Analysis revealed that RMSSD (ln) demonstrated a significant inverse relationship with BMI (β = -0.06; 95% CI = -0.12 – −0.01; p = 0.032), and the model accounted for 23% of the variance in RMSSD (ln). Notably, a one unit increase in BMI resulted in a reduction in RMSDD (ln) of 0.06. This investigation demonstrated evidence for a significant inverse linear relationship between vagally-mediated HRV and BMI in 3 – 5-year-old Australian children, similar to that of adults. Furthermore, this relationship was independent of age, sex and physical activity levels. Results may indicate that the cardiometabolic health of preschool children is, in part, influenced by the relationship between vagally-mediated HRV and weight status.

Effects of High-Intensity Interval Training and Moderate-Intensity Continuous Training on Cardiometabolic Risk Factors in Overweight and Obesity Children and Adolescents: A Meta-Analysis of Randomized Controlled Trials

Background: The purpose of this review was to compare the effectiveness of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on cardiometabolic risk factors of obese children and adolescents. Methods: Relevant studies published in PubMed, MEDLINE and Web of Science databases were searched. Only randomized controlled trials (RCTs) that examined the effect of HIIT and MICT on children and adolescents with obesity were included. Meta-analyses were conducted to determine the effect of HIIT on cardiometabolic risk factors using STATA software and potential moderators were explored (i.e., study duration, training modalities, work/rest ratio and work duration time). Results: Twelve RCTs involving 325 participants were included in the meta-analysis. HIIT showed more positive effects on maximal oxygen uptake (VO2max; SMD = 0.87, 95% CI: 0.39 to 1.35, p = 0.000) and systolic blood pressure (SBP; SMD = -0.64, 95% CI: -1.05 to -0.22, p = 0.003) than MICT. However, when compared with MICT, HIIT caused no significant differences in body weight, body mass index, body fat percentage, diastolic blood pressure and glycolipid metabolism markers. Furthermore, subgroup analysis showed that the effects of HIIT on VO2max and SBP were significantly different regarding protocol factors, such as modality, duration, training time, training settings, work/rest ratio and work duration. Conclusions: HIIT has a positive role in promoting cardiometabolic risk factors in obese children and adolescents. Moreover, when compared with MICT, HIIT had a more significant effect on improving cardiorespiratory fitness and systolic blood pressure. The factors of HIIT protocol had an important influence on the intervention effects of childhood obesity.

Influence of Chronic Exposure to Exercise on Heart Rate Variability in Children and Adolescents Affected by Obesity: A Systematic Review and Meta-Analysis

Background: Sedentary lifestyles are increasingly common amongst children, and insufficient physical activity is a global epidemic estimated to contribute to future incapacities and potential deaths. Objective: We aimed to increase the amount of evidence concerning the effect of chronic exposure to exercise on heart rate variability in children and adolescents affected by obesity. Methods: A systematic review commenced following the PRISMA guidelines developed by Web of Science, Virtual Health Library, PubMed, Cochrane Library, Embase, Ovid, Medline Complete, and Scopus using keywords obtained from the Descriptors in Health Sciences and Medical Subject Headlines (MeSH) terms. We considered (1) Population: Pediatric individuals affected by obesity; (2) Intervention: Exercise; (3) Control: Pre-intervention and sedentary; (4) Outcomes: Clearly presented primary parameters; and (5) Studies: Clinical trials, case controls, case reports, and case series. Results: 11 articles were involved and predominantly included procedures observed during approximately 12 weeks with a distribution of three sessions per week, each session being 30–60 min of aerobic exercise; additionally, the exercise grades were typically completed at a percentage of subjects’ maximum heart rates. The meta-analyses displayed a significant effect on the domains of time (R-R interval, SDNN, rMSSD), frequency (HF ms², HF (n.u.), LF/HF), and the non-linear index (SD1). Conclusions: Chronic exposure to exercise influences heart rate variability in children and adolescents affected by obesity by elevating the variability and parasympathetic activity and improving the sympathetic-vagal balance. Exercises should be recommended for the improvement of cardiac autonomic modulation to prevent the likelihood of further chronic diseases.

Physiotherapy and related management for childhood obesity: A systematic scoping review

INTRODUCTION

Despite targeted efforts globally to address childhood overweight/obesity, it remains poorly understood and challenging to manage. Physiotherapists have the potential to manage children with obesity as they are experts in movement and physical activity. However, their role remains unclear due to a lack of physiotherapy-specific guidelines. This scoping review aims to explore existing literature, critically appraising and synthesising findings to guide physiotherapists in the evidence-based management of childhood overweight/obesity.

METHOD

A scoping review was conducted, including literature up to May 2020. A review protocol exists on Open Science Framework at https://osf.io/fap8g/. Four databases were accessed including PubMed, Embase, CINAHL, Medline via OVID, with grey literature searched through google via "file:pdf". A descriptive synthesis was undertaken to explore the impact of existing interventions and their efficacy.

RESULTS

From the initial capture of 1871 articles, 263 intervention-based articles were included. Interventions included qualitative focused physical activity, quantitative focused physical activity and multicomponent interventions. Various outcome measures were utilised including health-, performance- and behaviour-related outcomes. The general trend for physiotherapy involvement with children who are obese appears to favour: 1) multicomponent interventions, implementing more than one component with environmental modification and parental involvement and 2) quantitative physical activity interventions, focusing on the quantity of bodily movement. These approaches most consistently demonstrated desirable changes across behavioural and health-related outcome measures for multicomponent and quantitative physical activity interventions respectively.

CONCLUSION

When managing children with obesity, physiotherapists should consider multicomponent approaches and increasing the quantity of physical activity, given consistent improvements in various obesity-related outcomes. Such approaches are well suited to the scope of physiotherapists and their expertise in physical activity prescription for the management of childhood obesity. Future research should examine the effect of motor skill interventions and consider the role of environmental modification/parental involvement as factors contributing to intervention success.

Biological and methodological factors affecting V ̇ O 2 max response variability to endurance training and the influence of exercise intensity prescription

NEW FINDINGS

What is the topic of this review? Biological and methodological factors associated with the variable changes in cardiorespiratory fitness in response to endurance training. What advances does it highlight? Several biological and methodological factors exist that each contribute, to a given extent, to response variability. Notably, prescribing exercise intensity relative to physiological thresholds reportedly increases cardiorespiratory fitness response rates compared to when prescribed relative to maximum physiological values. As threshold-based approaches elicit more homogeneous acute physiological responses among individuals, when repeated over time, these uniform responses may manifest as more homogeneous chronic adaptations thereby reducing response variability.

ABSTRACT

Changes in cardiorespiratory fitness (CRF) in response to endurance training (ET) exhibit large variations, possibly due to a multitude of biological and methodological factors. It is acknowledged that ∼20% of individuals may not achieve meaningful increases in CRF in response to ET. Genetics, the most potent biological contributor, has been shown to explain ∼50% of response variability, whilst age, sex and baseline CRF appear to explain a smaller proportion. Methodological factors represent the characteristics of the ET itself, including the type, volume and intensity of exercise, as well as the method used to prescribe and control exercise intensity. Notably, methodological factors are modifiable and, upon manipulation, alter response rates to ET, eliciting increases in CRF regardless of an individual's biological predisposition. Particularly, prescribing exercise intensity relative to a physiological threshold (e.g., ventilatory threshold) is shown to increase CRF response rates compared to when intensity is anchored relative to a maximum physiological value (e.g., maximum heart rate). It is, however, uncertain whether the increased response rates are primarily attributable to reduced response variability, greater mean changes in CRF or both. Future research is warranted to elucidate whether more homogeneous chronic adaptations manifest over time among individuals, as a result of exposure to more homogeneous exercise stimuli elicited by threshold-based practices.

Cardiovascular Effects of Aerobic Exercise With Self-Selected or Predetermined Intensity in Adolescents With Obesity

This study compared the effects of self-selected exercise intensity (SEI) versus predetermined exercise intensity (PEI) on blood pressure (BP) and arterial stiffness in adolescents with obesity. A total of 37 adolescents, 14.7 (1.6) years old, body mass index ≥95th percentile were randomly allocated into SEI (n = 18; 12 boys) or PEI (n = 19; 13 boys). Both groups exercised for 35 minutes on a treadmill, 3 times per week, for 12 weeks. The SEI could set the speed at the beginning of the sessions and make changes every 5 minutes. The PEI adolescents were trained at an intensity set at 60% to 70% of heart rate reserve. Brachial and central BP, pulse pressure, augmentation index, and carotid-femoral pulse wave were determined at baseline and after 12 weeks. Both groups reduced brachial systolic BP (SEI, Δ = -9 mm Hg; PEI, Δ = -4 mm Hg; P < .01), central systolic BP (SEI, Δ = -4 mm Hg; PEI, Δ = -4 mm Hg; P = .01), and central pulse pressure (SEI, Δ = -4 mm Hg; PEI, Δ = -3 mm Hg; P = .02) without differences between groups. No changes in the augmentation index and carotid-femoral pulse wave were observed in either group. The SEI induced similar changes in various cardiovascular outcomes compared with PEI in adolescents with obesity.

Effects of a Short-Term Resistance-Training Program on Heart Rate Variability in Children With Cystic Fibrosis-A Randomized Controlled Trial

Background: Cystic fibrosis (CF) affects the autonomic nervous system (ANS) and exercise in healthy children modulates the interaction between sympathetic and parasympathetic activity. This study aimed to evaluate the effects of a short-term resistance exercise program on heart rate variability (HRV) in children and adolescents with CF.

Methods: A randomized controlled trial was carried out in children diagnosed with CF aged 6–18 years. Individuals were divided into two groups: control (CON) and resistance-training (EX). Individuals in the EX group completed an individualized guided resistance program (5-RM—60–80%) for 8 weeks (3 sessions of 60 min/week). Upper and lower limbs exercises (seated bench press, seated lateral row, and leg press) were used. HRV was measured using a Suunto watch with subjects in lying position.

Results: Nineteen subjects (13 boys) were included (CON = 11; and EX = 8). Mean age was 12.2 ± 3.3, FEV₁ (forced expiratory volume in the first second) z-score was 1.72 ± 1.54 and peak oxygen consumption (VO₂peak) 42.7 ± 7.4 mL.Kg^–1.min^–1. Exercise induced significant changes in the frequency-domain variables, including a decrease in LF power (p = 0.001, d = 0.98) and LF/HF ratio (p = 0.020, d = 0.92), and an increase in HF power (p = 0.001, d = −0.97), compared to the CON group. No significant changes were found for time-domain variables, although increases with a moderate effect size were seen for SDNN (p = 0.152, d = −0.41) and RMSSD (p = 0.059, d = −0.49) compared to the CON group.

Conclusion: A short-term resistance exercise-training program was able to modulate HRV in children and adolescents with CF presenting mild to moderate lung function impairment and good physical condition.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier NCT04293926.

High-Intensity Interval Training versus Moderate-Intensity Continuous Training on Health Outcomes for Children and Adolescents: A Meta-analysis of Randomized Controlled Trials

Low cardiorespiratory fitness (CRF) is considered as an established risk factor for cardiovascular and metabolic disorders. However, the effectiveness of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) in children and adolescents remained uncertain. Electronic databases of the PubMed, EmBase, and the Cochrane library were searched for randomized controlled trials (RCTs) investigated the role of HIIT versus MICT for children and adolescents throughout December 2019. Sixteen RCTs involving a total of 543 children were selected for final meta-analysis. HIIT versus MICT showed high peak VO2 (weighted mean differences (WMD): 2.68; 95% confidence intervals (CIs): 1.81 to 3.55; $P<0.001$ ), and no evidence of heterogeneity and publication bias was detected. However, there were no significant differences detected between HIIT and MICT on the levels of peak heart rate (HRmax), fat mass, free fat mass, weight, body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, glycemia, insulinemia, total cholesterol, high density lipoprotein, low density lipoprotein, triglycerides, HOMA-IR, HbA1c, and leptinemia. The findings of this study revealed that HIIT versus MICT showed a significant improvement in peak VO2 in children and adolescents. Further large-scale RCTs should be conducted to compare the long-term effects of HIIT versus MICT in children and adolescents.

Effectiveness of martial arts exercise on anthropometric and body composition parameters of overweight and obese subjects: a systematic review and meta-analysis

BACKGROUND

Obesity is considered a top public health concern, and its prevalence is growing every day. Thus, interventions to address this problem should be encouraged and further studied. In this regard, the aim of this review was to summarize the evidence of martial arts interventions to evaluate their effectiveness on the anthropometric and body composition parameters of overweight and obese subjects.

METHODS

A systematic literature search was conducted on January 26, 2020 using the PubMed, Medline, Lilacs, Cochrane, and Scielo databases. Reference lists of eligible articles and relevant reviews have also been examined. All randomized clinical trials on martial arts that evaluated the anthropometric and body composition parameters of overweight and obese subjects were included, and a narrative synthesis of eligible studies was conducted in accordance with PRISMA guidelines. The Downs & Black checklist was used to assess the quality of the studies. This review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (identifier CRD42018086116).

RESULTS

A total of 82 articles were identified from the initial search strategy. A further 2 articles were identified from the review of relevant bibliographies. Six studies encompassing 258 participants who were overweight or obese were included. Four studies reported Tai Chi practice, one study reported Kung Fu exercise, and another study reported martial arts exercise. The examined meta-analyses did not reveal significant benefits from martial arts practice over control groups after the experiment period for body mass index (- 1.34 kg/m2; 95% CI: - 2.72, 0.05), waist circumference (1.41 cm; 95% CI: - 0.72, 3.54) and percentage of body fat (- 0.75%; 95% CI: - 5.58, 4.08).

CONCLUSION

The scarcity, heterogeneity, short intervention time, small sample size, and significant methodological limitations of the available studies do not allow to conclude whether martial arts are effective in the anthropometric and body composition parameters of overweight and obese individuals. This study highlights the need for more research to assess the benefits of martial arts for overweight and obese individuals.

A pilot study of the effects of a high-intensity aerobic exercise session on heart rate variability and arterial compliance in adolescents with or without type 1 diabetes

Arterial compliance and autonomic regulation are predictors of cardiovascular disease. In adults, both are altered chronically by type 1 diabetes (T1D) and acutely by exercise; however, the effects of T1D and exercise are less clear in adolescents. We measured short-term effects of a high-intensity aerobic interval exercise session on cardiovascular and metabolic variables in normal weight adolescents with T1D or without T1D (Control). Energy expenditure (EE), heart rate variability (HRV), arterial compliance, and blood pressure (BP) were measured before exercise (baseline) and three times over 105 minutes postexercise. The T1D and control groups had similar cardiorespiratory fitness and accelerometer-measured physical activity. The T1D group had higher EE and fat oxidation throughout the trial, but postexercise changes were similar between groups. HRV transiently declined following exercise in both groups, but the T1D group had lower HRV at baseline. Among the measures of arterial compliance, the augmentation index declined postexercise while carotid-femoral pulse wave velocity and large artery elastic index remained unchanged. Central and brachial BP were unchanged following exercise until the final measurement, when a small increase occurred. However, arterial compliance and BP did not differ between groups. These results demonstrate that normal weight adolescents with T1D have impaired autonomic function and increased EE and fat oxidation compared to peers without diabetes who have similar levels of fitness and physical activity. However, acute cardiometabolic responses to exercise are normal in T1D with adequate glycemic control. Changes in arterial compliance and BP may take longer to emerge in relatively healthy adolescents with T1D.

Aerobic Training Performed at Ventilatory Threshold Improves Psychological Outcomes in Adolescents With Obesity

BACKGROUND

Physical activity may be as effective as some drugs for improving psychological outcomes; however, vigorous exercise may be needed for improving these outcomes in adolescents with obesity. The aim of this study is to examine the effects of low- and high-intensity training on self-esteem and symptoms of depression and anxiety in adolescents with obesity.

METHODS

A total of 62 pubertal adolescents with obesity (age 15 [1.5] y, body mass index 34.87 [4.22] kg/m2) were randomized into high-intensity group (HIG, n = 31) or low-intensity group (LIG, n = 31) for 24 weeks. All participants also received nutritional, psychological, and clinical counseling. Body composition and measures of depressive symptoms, anxiety, and self-esteem were assessed at baseline and after 24 weeks.

RESULTS

Depressive symptoms decreased significantly in both HIG (d = 1.16) and LIG (d = 0.45) (P ≤ .01). Trait anxiety decreased after 24 weeks for HIG (d = 0.81, P = .002) and LIG (d = 0.31, P = .002). No changes were observed in state anxiety or self-esteem.

CONCLUSIONS

Results from the present study demonstrate that 24 weeks of multidisciplinary intervention improves depression and anxiety symptoms in adolescents with obesity; however, the magnitude of changes is higher in HIG compared with LIG.

Response of obese schoolchildren to high-intensity interval training applied in the school context

BACKGROUND

High-intensity interval training (HIIT) has been widely used to fight cardiovascular risk factors in adolescents and adults, but no data are available on its applicability in children.

OBJECTIVES

To assess the effects of HIIT on different anthropometric and cardiovascular parameters of overweight and obese children aged 7-9 years.

MATERIAL AND METHODS

Four groups were formed: 1) an overweight control group (OWCG, n=30, BMI=21.60±3.72kg/m²); 2) an obesity control group (OCG, n=34, BMI=23.92±3.11kg/m²); 3) an overweight intervention group (OWIG, n=69, BMI=20.01±1.88kg/m²), and 4) an obesity intervention group (OIG, n=141, BMI=24.12±2.66kg/m²). BMI, body fat (BF), waist circumference, height-waist ratio, systolic and diastolic blood pressure and cardiorespiratory fitness (CRF) were assessed before and after intervention.

RESULTS

There were significant differences in BMI (P<.001), BF (P<.001), and CRF (P<.001) between the groups (control vs. intervention) before and after intervention (OWCG vs. OWIG and OCG vs. OIG). BMI decreased in the OWIG (BMI, 20.01±1.88 at baseline vs. 19.00±2.02 after HIIT, P<.001) and OIG (BMI, 24.12±2.66 at baseline vs. 23.23±3.23 after HIIT, P<.001) groups. Similarly, BF decreased in the OWIG (BF, 21.84±4.97 at baseline vs. 19.55±4.81% after HIIT, P<.001) and OIG (BF, 30.26±11.49 at baseline vs. 26.81±6.80% after HIIT, P<.001) groups. CRF improved in both intervention groups (P<.001). There was a significant decrease in the prevalence rate of schoolchildren with obesity (from 66.4% to 49.6%) (P<.001).

CONCLUSION

The intervention conducted in the school setting improved the anthropometric and cardiovascular parameters of schoolchildren, and also allowed for reducing the proportion of schoolchildren with obesity.

Cardiac autonomic function and its association with cardiometabolic disease risk factors in Black South African children

OBJECTIVE

This study evaluated the associations between cardiac autonomic nervous system (ANS) activity and cardiometabolic disease (CMD) risk factors among black South African children.

DESIGN

The participants included 34 black South African children (11.85 ± 0.89 y). CMD risk factors included waist circumference (WC), hip circumference (HC), body mass index z-score (BMI z-score), blood pressure (SBP, DBP), total cholesterol (TC), high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), fasting glucose (FG), fasting insulin (FINS), and vessel stiffness index (SI). Heart rate variability was used to quantify cardiac ANS activity.

RESULTS

lnRMSSD, pNN50 and lnSD1 were inversely associated with FINS (r = -0.33, p = 0.05; r = -0.36, p = 0.03; r = -0.41, p = 0.01), WC (r = -0.45, p = 0.01; r = -0.39, p = 0.02; r = -0.45, p = 0.01), and HC (r = -0.41, p = 0.01; r = -0.36, p = 0.03; r = -0.43, p = 0.01). HDL was positively associated with lnRMSSD (r = 0.37; p = 0.03) and lnSD1 (r = 0.37; p = 0.03) while, LDL was negatively associated with HF (r = -0.41; p = 0.01). Regression analysis identified WC as the primary predictor for parasympathetic modulation in time domain (lnRMSSD: r2 = 0.21, p = 0.01; pNN50: r2 = 0.18, p = 0.01) and non-linear domain (lnSD1: r2 = 0.21, p = 0.01).

CONCLUSION

Elevated resting parasympathetic activity in children is associated with lower CMD risk factors and an elevation in the protective HDL.

Effect of High-Intensity Interval Training versus Moderate-Intensity Continuous Training on Cardiorespiratory Fitness in Children and Adolescents: A Meta-Analysis

Enhancing cardiorespiratory fitness (CRF) can lead to substantial health benefits. Comparisons between high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on CRF for children and adolescents are inconsistent and inconclusive. The objective of this study was to perform a meta-analysis to compare the effects between HIIT and MICT on CRF in children and adolescents. We searched MEDLINE, PubMed, Web of Science, and Google Scholar to identify relevant articles. The standardized mean differences (SMD) and 95% confidence intervals (95% CI) were calculated to determine the pooled effect size of HIIT and MICT on CRF. A total of 563 subjects from 17 studies (18 effects) were identified. The pooled effect size was 0.51 (95% CI = 0.33-0.69) comparing HIIT to MICT. Moreover, intervention duration, exercise modality, work and rest ratio, and total bouts did not significantly modify the effect of HIIT on CRF. It is concluded that compared with endurance training, HIIT has greater improvements on cardiorespiratory fitness among children and adolescents.

Feasibility of incorporating high-intensity interval training into physical education programs to improve body composition and cardiorespiratory capacity of overweight and obese children: A systematic review

BACKGROUND/OBJECTIVE

High-intensity interval training (HIIT) can produce similar or improved results compare with traditional training, but the question as to whether HIIT can be used in the setting of physical education (PE) remains unanswered. The aim of this systematic review was to critically analyze the feasibility of incorporating HIIT programs into PE classes to improve the body compositions and cardiorespiratory fitness of overweight students.

METHODS

We conducted database searches for literature dating between January 2012 and January 2017. Of the final six studies selected, three were conducted in children under 12 years old and three involved adolescents between 12 and 18 years old.

RESULTS

The HIIT protocols consisted of 2-3 sessions per week, with intervals of 15 s and passive or active rests of 15 s, totaling up to 6 min of work with 4 min of rest. The duration of HIIT programs was 6-24 weeks. Significant changes were reported in body composition, body mass index, body fat (%), waist circumference, and sum of skinfolds; and increases in muscle mass were observed. The inclusion of HIIT programmes improved maximal oxygen uptake (VO2max), performance in the intermittent Yo-Yo test and maximal aerobic speed.

CONCLUSIONS

The HIIT programmes showed improvements in the variables studied, with interventions two or three times weekly. Therefore, they can be used in schools, as a strategy to combat the childhood obesity pandemic and HIIT can be use alongside with existing PE activities within the same lesson or in specific periods during day school.

Short-Term High-Intensity Interval Training Is Superior to Moderate-Intensity Continuous Training in Improving Cardiac Autonomic Function in Children

OBJECTIVES

This study aimed to investigate the impact of 3 isocaloric exercise programs on cardiac autonomic nervous system (ANS) functioning in children.

METHODS

One hundred nine children (39% boys and 61% girls) aged 10-13 years (mean 11.07 ± 0.81) were conveniently assigned to 1 of 4 groups as follows: Moderate-intensity continuous training (MICT; n = 29) at 65-70% of the predicted maximum heart rate (MHR), High-intensity interval training (HIIT; n = 29) at > 80% of the predicted MHR, HIIT and MICT combined on alternate weeks (ALT; n = 27), and a control group (n = 24). Morning ANS activity was assessed via analysis of heart rate variability (HRV), with the patient in supine position for 10 min, before and after the exercise intervention.

DATA ANALYSIS

A 2-way analysis of variance was used to evaluate the effects of training on all HRV parameters (p < 0.05/4 = 0.0125).

RESULTS

After 5 weeks of training, significant improvements were observed for ln of the standard deviation of normal-to-normal intervals (p < 0.0001), ln of the root mean square of successive difference (p < 0.0001), and ln of standard deviation 1 (p < 0.0001), with superior results reported in the HIIT group (effect size [ES] = 2.22, 2.69, and 2.69) compared with the MICT (ES = 1.67, 1.75, and 1.75) and ALT (ES = 0.87, 1.06, and 1.06) groups, respectively.

CONCLUSION

Short-term HIIT seems to induce superior alterations in cardiac ANS activity compared to MICT and ALT in children through enhanced vagal activity.

Transtheoretical model for change in obese adolescents: MERC randomized clinical trial

The randomized controlled trial evaluated the effectiveness of an intervention based on the Transtheoretical Model of Change on anthropometric, metabolic and motivational outcomes in obese adolescents. A total of 135 male and female adolescents were randomized to two groups: intervention group (n = 65) and control group (n = 70). The adolescents were evaluated 1 week before the interventions began and at the end of 12 weeks. There was no statistically significant difference between groups in the outcome variables. Intervention group reported magnitude of effect more expressive on body mass index percentile, waist circumference, waist-to-hip ratio, readiness to change diet and readiness to start exercise.

AEROBIC TRAINING IN OBESE ADOLESCENTS: A MULTIDISCIPLINARY APPROACH

ABSTRACT Introduction: The prevalence of excess weight/obesity in adolescence has increased, and physical training may be effective in combating this scenario. Objective: To analyze the effect of different intensities of aerobic training on the body composition of obese adolescents undergoing multidisciplinary intervention. Methods: In this study, 107 pubertal (Tanner 3 and 4), obese (BMI=34.72±4.10 kg/m²) adolescents (14.85±1.44 years) were randomly assigned to three groups: high intensity training (HITG – ventilatory threshold I (VTI)); low intensity training (LITG – 20% below the VTI) and control group (CG), without intervention. The adolescents in the HITG and LITG underwent nutritional and psychological (1x/week) and clinical (1 x/month) follow-up and physical training (3x/week) for 12 weeks. Results: Reductions in fat mass (FM) and body fat percentage (BFP) (p< 0.001) and an increase in fat-free mass (FFM) (p<0.001) were observed in all groups. There was a reduction in BMI only in the experimental groups (p<0.001). Conclusion: The effects of multidisciplinary treatment on the body composition of obese adolescents occur independently of the intensity of aerobic physical training. Level of Evidence I; High quality randomized clinical studies with or without statistically significant difference, but with narrow confidence intervals.

Exercise training in overweight and obese children: Recreational football and high-intensity interval training provide similar benefits to physical fitness

This study compared the effects of recreational football and high-intensity interval training (HIIT) on body composition, muscular fitness, and cardiorespiratory fitness in overweight and obese children. Forty-two overweight/obese males aged 11-13 years [body mass index (BMI) >20.5 kg/m² ] were randomly assigned to a recreational football training group (n = 14; 157.9 ± 5.8 cm; 63.7 ± 12.6 kg), HIIT group (n = 14; 163.8 ± 9.4 cm; 71.5 ± 10.5 kg), or nontraining control group (n = 14; 162.7 ± 9.3 cm; 67.4 ± 16.1 kg). Physical fitness components were measured at baseline and after 12 weeks of training at the same time of the day and under similar conditions, including body composition, muscular fitness (lower-body power, change-of-direction speed, and flexibility), and cardiovascular fitness (Yo-Yo Intermittent Endurance test distance, resting heart rate, and blood pressure). Lean body mass (4.3%, ES = 0.40; 95% CI: -0.48, 1.29; P = .382) and muscle mass 4.4% (ES = 0.40; 95% CI: -0.48, 1.29; P = .378) very likely increased in the recreational football group, while possible improvements were observed in the HIIT group (lean body mass: 2.5%, ES = 0.22; 95% CI: -0.62, 1.06; P = .607, muscle mass: 2.8%, ES = 0.23; 95% CI: -0.61, 1.07; P = .594). Only trivial increases were observed in the control group for lean body mass (0.5%, ES = 0.05; 95% CI: -0.70, 0.79; P = .906) and muscle mass (1.1%, ES = 0.09; 95% CI: -0.65, 0.83; P = .814). Significant differences were found between the recreational football and control groups in post-training body mass (P = .034) and body mass index (P = .017). Body fat very likely decreased in the recreational football group (-7.7%, ES = -0.41; 95% CI: -1.29, 0.48; P = .376) and possibly decreased in the HIIT group (-5.2%, ES = -0.22; 95% CI: -1.05, 0.62; P = .607), with a trivial reduction in the control group (-1.1%, ES = -0.04; 95% CI: -0.78, 0.70; P = .914). Very likely increases in lower-body power were evident in the recreational football (17.0%, ES = 0.76; 95% CI: -0.15, 1.66; P = .107) and control groups (16.1%, ES = 0.55; 95% CI: -0.20, 1.31; P = .156), while small improvements were observed in the HIIT group (6.0%, ES = 0.24; 95% CI: -0.60, 1.08; P = .580, possible). Likely to most likely improvements in Yo-Yo Intermittent Endurance test performance and change-of-direction speed were noted in the recreational football group (Yo-Yo: 79.8%, ES = 1.09; 95% CI: 0.16, 2.03; P = .025, change-of-direction speed: -10.6%, ES = -1.05; 95% CI: -1.98, -0.12; P = .031) and the HIIT group (Yo-Yo: 81.2%, ES = 1.03; 95% CI: 0.15, 1.92; P = .025, change-of-direction speed: -5.4%, ES = -0.91; 95% CI: -1.79, -0.04; P = .045). Diastolic blood pressure likely decreased in the recreational football (-8.6%, ES = -0.74; 95% CI: -1.64, 0.17; P = .116) and HIIT groups (-9.8%, ES = -0.57; 95% CI: -1.40, 0.30; P = .195), with a possible increase in the control group (1.2%, ES = 0.21; 95% CI: -0.53, 0.96; P = .068). Recreational football and HIIT elicited improvements in all muscular and cardiorespiratory fitness measures. In contrast, the control group, which performed only physical education classes, increased body mass, BMI, and fat mass. Therefore, additional activities such as recreational football or HIIT might counter the prevalence of overweight and obesity in children.

Effects of 28 weeks of high-intensity interval training during physical education classes on cardiometabolic risk factors in Chilean schoolchildren: a pilot trial

The purpose of this investigation was to determine the effects of 28 weeks of high-intensity interval training (HIIT) during physical education classes on the weight status, cardiorespiratory capacity, and blood pressure of overweight and obese schoolchildren. The participants included 197 schoolchildren (108 girls and 89 boys) aged between 6 and 11 years (8.39 ± 1.15 years) in four groups: experimental group 1 (EG1) = 59 overweight schoolchildren; experimental group 2 (EG2) = 92 obese schoolchildren; control group 1 (CG1) = 17 overweight children; and control group 2 (CG2) = 29 obese schoolchildren. The participants in the EGs carried out HIIT twice per week for 28 weeks. After the 28-week intervention, the participants showed significant reductions in body mass index (p < 0.001). Waist circumference of boys in EG2 and waist-to-height ratio of girls in EG2 was significantly reduced (p < 0.05). Body fat percentage diminished, for girls in both groups and boys in EG2 (p < 0.05). Furthermore, the program significantly reduced the number of hypertensive schoolchildren (p = 0.001) and reduced the percentage of obese schoolchildren. The distance covered in the 6-min walk test improved significantly for girls in EG1 and EG2 (p < 0.05) and boys in EG2.

CONCLUSIONS

The 28-week HIIT program caused significant improvements in the cardiorespiratory capacity, anthropometric variables, and blood pressure levels of overweight and obese children. What is Known: • High-intensity interval training (HIIT) programs improve health, but investigations have used relatively short intervention periods. What is New: • The 28-week period (a large intervention period) of HIIT-based games during physical education classes caused significant improvements in cardiorespiratory capacity, anthropometric variables, and blood pressure levels of overweight and obese schoolchildren.

CARDIOVASCULAR EFFECTS OF 16 WEEKS OF MARTIAL ARTS TRAINING IN ADOLESCENTS

ABSTRACT Introduction: Sedentary habits increase the chances of developing cardiovascular disease. Physical activity is one of the means of prevention and treatment of these diseases, thus martial arts represent a dynamic option in promoting physical activity. Objective: The objective of the study is analyze the effects of 16 weeks of Martial Arts (Muay Thai or judo) training on cardiovascular variables in adolescents. Methods: The sample consisted of 40 adolescents, aged 11 to 14 years, divided into two groups: Martial Arts (n=28) and control (n=12). Weight and height measurements were taken to calculate body mass index. Systolic and diastolic blood pressure (BP), heart rate (HR) at rest, pulse pressure (PP) and rate-pressure product (RPP), were also measured. The intervention was carried out through Martial Arts (Muay Thai and judo) training held twice a week for 90 minutes, over 16 weeks. The control group did not undergo any training. The statistical analysis was performed using the following tests: Shapiro-Wilks, Levene’s, analysis of covariance (ANCOVA), eta-squared effect size and the net-effect, using SPSS 15.0 software and a significance level of 5%. Results: There was no statistical difference between the control and Martial Arts groups for the sample characterization. There was a significant difference in systolic BP in the Martial Arts group when compared with the control group (p-value=0.049). The effect size can be considered moderate (effect size=0.163), with a good net-effect (3.4 mmHg). Conclusion: This study showed that 16 weeks of Martial Arts decreased systolic BP in normotensive adolescents. Level of Evidence II; Therapeutic studies - Investigating the results of treatment.

Physical Activity and Heart Rate Variability in Adolescents with Abdominal Obesity

Physical activity is a protective factor for autonomic dysfunction. However, whether this occurs in adolescents with abdominal obesity is still unclear. Thus, the aim of this study was to analyze the association between physical activity and heart rate variability (HRV) in adolescents with and without abdominal obesity. This cross-sectional study included 1152 boys (age: 17 ± 1 years). HRV measures of time (root mean square of the squared differences between adjacent normal RR intervals-RMSSD and the percentage of adjacent intervals over 50 ms-PNN50) and frequency domains (balance sympathetic-vagal-LF/HF) were evaluated, as well as total physical activity, commuting physical activity, leisure-time physical activity, and abdominal obesity. All physical activity domains were associated with better RMSSD, PNN50, and LF/HF in normal weight adolescents (p < 0.05), whereas in adolescents with abdominal obesity only leisure-time physical activity was associated with better PNN50 (b = 0.174, p = 0.035) independent of age, period of the day, body mass index, and blood pressure. In conclusion, higher leisure-time physical activity, but not total and commuting physical activity levels, was associated with improved HRV in adolescents with abdominal obesity.

Effect of Low- Versus High-Intensity Exercise Training on Biomarkers of Inflammation and Endothelial Dysfunction in Adolescents With Obesity: A 6-Month Randomized Exercise Intervention Study

PURPOSE

To investigate the effects of a low- versus high-intensity aerobic training on biomarkers of inflammation and endothelial dysfunction in adolescents with obesity.

METHODS

Sixty-two adolescents with obesity [age = 15 (14) y, body mass index = 34.87 (4.22) kg·m^-2] were randomized to receive either a high-intensity training (HIT, n = 31) or a low-intensity training (LIT, n = 31) for 24 weeks. All participants also received nutritional, psychological, and clinical counseling. Leptin, total and subtype leukocyte counts, tumor necrosis factor-alpha, interleukin-6, myeloperoxidase, soluble intercellular adhesion molecule-1, and soluble vascular cell adhesion molecule-1 were obtained at baseline and after 24 weeks.

RESULTS

HIT reduced neutrophils [from 4.4 (1.9) to 3.6 (1.3) µL^-1 × 10³; P = .01] and monocytes [from 7.2 (2.5) to 5.2 (1.8) µL^-1 × 10²; P < .01], but LIT increased neutrophils [from 4.5 (1.7) to 5.2 (3.3) µL^-1 × 10³; P = .01]. Although tumor necrosis factor-alpha increased in LIT [from 13.3 (7.5) to 17.7 (10.8) pg·mL^-1; P = .01], it decreased in HIT [from 12.4 (7.5) to 11.3 (6.2) pg·mL^-1; P = .01]. No changes in leukocyte counts, soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and homeostasis assessment model for insulin resistance were observed.

CONCLUSIONS

Both HIT and LIT improved the inflammatory profile. The study, however, indicated that the number of biomarkers and the magnitude of changes were higher in the HIT compared with LIT.

Overweight and obesity are not associated to high blood pressure in young people sport practitioners

The aim of this study was to analyze the association between overweight and obesity with high blood pressure (HBP) according to sports practice in young people. Took part in this study 636 young people aged 10 to 17 years of Londrina, Parana State, Brazil. Sex, age, parental education, sedentary behavior, sports practice, nutritional status and blood pressure were analysed. Poisson regression was used to estimate the prevalence ratio (PR) and 95% confidence intervals. Overweight and obesity young people showed higher prevalence of HBP compared to eutrophics when analysed the total sample (25,7 e 29,5 vs 15,2%) and non sport practitioners (29,7 e 33,3 vs 15,1%), which did not occur with sports practitioners (17,1 e 18,2 vs 15,5%). Positive associations were found between overweight and obesity with HBP in total sample (PR = 1,60, 1,02-2,52 and 1,93, 1,15-3,25) and on non sport practitioners (RP = 1,80, 1,05-3,14 and 2,15, 1,10-4,16). For young people sports practitioners were not found associations between overweight and obesity with HBP (PR = 1,01, 0,36-2,82 and 1,09, 0,48-2,48). Weight excess was not associated with HBP in young people sports practitioners, suggesting cardiovascular protection in young people with overweight and obesity.

Weight loss interventions for overweight and obese adolescents: a systematic review

PURPOSE

To determine what factors contribute to the efficacy of non-drug treatments designed to promote weight loss in overweight and obese adolescents.

METHODS

Data sources Medline/PubMed; Psychinfo; EMBASE; Web of Science (ISI); and Cochrane Central Register of Controlled Trials. Study selection Randomized clinical trials of treatments for obesity and overweight in adolescents aged 10-19 years with a minimum duration of 2 months. Data extraction 115 of the 12,948 publications retrieved met eligibility criteria and 26 were included in the final sample. Period of extraction January 2004 to November 2014.

RESULTS

The Delphi list was used to evaluate the methodological quality of the studies (M = 5.58, SD = 1.027). There was considerable variability between the interventions, but they were all multifactorial, with components such as nutritional education, physical activity, family support and psychological therapy. The number of contacts with subjects during the course of the intervention was a predictor of treatment efficacy when the groups were compared. Limitations This systematic review was limited to trials reported in English and by the lack of methodological rigor and shortcomings in reporting in the studies reviewed.

CONCLUSIONS

Multidisciplinary interventions including family support and guided behavior modification appear to be effective methods of reducing BMI in overweight and obese adolescents.

Self-initiated changes in physical activity levels improve cardiometabolic profiles: A longitudinal follow-up study

BACKGROUND AND AIMS

While studies have described the importance of higher physical activity levels (PAL) in weight loss, the impact of self-initiated PAL on health status warrants further study. We aimed to prospectively examine the effects of self-initiated longitudinal PAL changes on body mass index (BMI) and cardiometabolic parameters in normal weight, overweight and obese adults.

METHODS AND RESULTS

We included 4840 adults (mean age 41.6 ± 7.9 years, 79% male) undergoing routine health screening examinations. Self-reported PAL, height, weight, blood pressure and blood samples were collected at baseline and after a mean (95% confidence interval) follow up of 536 (531-541) days. Subjects were stratified according to BMI [39.8% normal weight (<25 kg/m²), 45.1% overweight (25.0-29.9 kg/m²), and 19.1% obese (≥30 kg/m²)]. In normal weight individuals, BMI increased from baseline to follow-up, irrespective of PAL changes. On the other hand, overweight and obese individuals that increased PAL experienced a decrease in BMI by -0.9% and -3.1%, respectively (p < 0.05). Overweight and obese individuals that increased PAL also experienced a decrease in -5.8% -4.6% in non-HDL concentrations from baseline to follow-up (p < 0.05). Finally, in overweight individuals, LDL cholesterol concentrations decreased from baseline to follow-up, irrespective of PAL changes whereas in obese individuals, a maintenance or increased PAL were associated with a decrease in -4.7% and -6.1% (p < 0.05), respectively.

CONCLUSIONS

In a large cohort of screening patients, longitudinal self-initiated PAL is associated with improved BMI and cardiometabolic profile in overweight and obese individuals.