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

Reduction in blood pressure and metabolic profile in overweight hypertensive boys participating in a 12-week aerobic exercise program

Strategies for controlling hypertension include reducing excess fat and increasing muscle mass. However, the effects of exercise interventions on hypertension in adolescents have been little investigated. The purpose was to evaluate the effect of 12 weeks of aerobic exercise on systolic blood pressure (SBP) and diastolic blood pressure (DBP) and the cardiometabolic profile of overweight hypertensive and non-hypertensive boys. The sample included 107 boys diagnosed as overweight, aged between 12 and 17, divided into two non-hypertension groups, one control (GCN, n = 14) and one with exercise (GEN, n = 55), as well as two groups of hypertensives, one control (GCH, n = 12) and one with exercise (GEH, n = 26). The boys were assessed at the study baseline and after 12 weeks in terms of anthropometric parameters, biological maturation, SBP, DBP and mean blood pressure (MBP), lipid, and metabolic profile. The aerobic training programs lasted 12 weeks and were carried out in three weekly sessions at different intensities. The high-intensity interval training session lasted around 35 min at an intensity of 80-100% of the reserve heart rate, and the moderate-intensity of continuous training session lasted 60 min at an intensity of 35-75% of the reserve heart rate. Caloric expenditure was equivalent between the exercises (p = 0.388). CGN and CGH participated only in school physical activities. Repeated measures analysis of variance and clinical effect analysis using Cohen's effect size were used, with a significance level established at p < 0.05. After 12 weeks, all groups increased their height (p < 0.05), but only the exercise groups showed a reduction in anthropometric variables (p < 0.05), with a possibly beneficial effect in GEN (d =  - 0.203; p = 0.003). No differences were found in the variables for the GCN. The GCH and GEH groups reduced SBP (p < 0.05), but only GEH showed a reduction in DBP (p = 0.005) and MBP (p = 0.001). In relation to the lipid profile, GEH maintained HDL-c close to baseline values, while GCH showed a reduction in HDL-c (p = 0.021). Regarding the clinical effect of exercise on hypertension, GEH showed a large and very beneficial effect size on DBP (d =  - 0.916; p = 0.006) and MBP (d =  - 0.926; p = 0.005).Conclusion: Hypertensive boys who practiced physical exercise showed greater effects in reducing blood pressure, indicating the importance of non-drug therapeutic management in overweight adolescents.Trial registration:Brazilian Registry of Clinical Trials RBR-4v6h7b / RBR-6343y7.

Elevated blood pressure in children with cerebral palsy and its relationship with adiposity and physical activity

BACKGROUND

There is a high prevalance of hypertension in adults with with cerebral palsy (CP). However, less is known about blood pressure in children with CP.

OBJECTIVE

The aim was to determine if blood pressure is elevated in children with CP and whether it is related to adiposity and physical activity.

METHODS

Thirty children with spastic CP (5-11 y) and 30 age-, sex-, and race-matched typically developing control children were studied. Resting systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate were measured, and mean arterial pressure (MAP) was calculated. Visceral fat mass and total body fat mass index (FMI) were determined using dual-energy X-ray absorptiometry. Physical activity was assessed using accelerometer-based monitors.

RESULTS

Children with CP had higher DBP and heart rate than controls (p < 0.05). DBP percentile and MAP were also higher in children with CP when BMI was statistically controlled. Children with CP and elevated blood pressure or hypertension (n = 8) had 56% more visceral fat mass than children with CP and normal blood pressure (n = 22; p < 0.05). In the groups combined, blood pressure was directly related to visceral fat mass and FMI, and inversely related to physical activity (p < 0.05). However, in children with CP alone, only visceral fat mass was related to blood pressure (p < 0.05).

CONCLUSIONS

Children with CP have higher resting blood pressure than typically developing children. The higher blood pressure is related to higher visceral adiposity. Careful blood pressure screening should start during childhood in individuals with CP.

Assessment of Step Tracker Mobile Applications for the Promotion of Physical Activity by Adolescents Based on Their Weight Status

The objectives of the present study were to analyze the adherence of normal weight and overweight/obese adolescents to intervention with mobile applications; to establish the differences in the evaluation of the mobile application and in the problematic use of the mobile phone between normal weight and overweight/obese adolescents; and to determine the relationship between the distance travelled, the evaluation of the mobile applications, and the conflictive use of the mobile phone. A quasi-experimental design was carried out with the participation of 70 adolescents between 12 and 16 years old (mean age: 14.25 ± 1.23 years old; 38 normal weight and 32 overweight/obese). The adolescents completed a 10-week intervention in which they used step tracker mobile applications for the promotion of physical activity, a minimum of three times per week. Problematic mobile phone use and adolescent ratings of the application used were measured. The results showed no significant differences in adolescents' adherence to the intervention according to the mobile application used (p = 0.191) or weight status (p = 0.202). In addition, significant differences were not found in the assessment of mobile applications within the group of overweight and obese adolescents: engagement (p = 0.471), functionality (p = 0.319), aesthetics (p = 0.378), information (p = 0.184), usability (p = 0.154), or perceived impact (p = 0.139), although differences were found in the assessment made by normal-weight adolescents in information (p = 0.029), usability (p = 0.029), and perceived impact (p = 0.044), where Pacer had better scores than Pokémon Go in the first two dimensions. No greater problematic mobile phone use was found after the intervention according to weight status (p = 0.311) nor the mobile application used (p = 0.985). It can be concluded that there is similar adherence among normal weight and overweight/obese adolescents to interventions with mobile applications to promote physical activity. It is noteworthy that adolescents, regardless of weight status, showed a positive perception towards the use of these mobile applications.

How Can Promoting Skeletal Muscle Health and Exercise in Children and Adolescents Prevent Insulin Resistance and Type 2 Diabetes?

Skeletal muscle secretome, through its paracrine and endocrine functions, contributes to the maintenance and regulation of overall physiological health. We conducted a narrative review on the role of skeletal muscle and exercise in maintaining glucose homeostasis, driving insulin resistance (IR), and preventing type 2 diabetes in pediatric populations, especially in the context of overweight and obesity. Myokines such as interleukin (IL)-6, IL-8, and IL-15, as well as irisin, myonectin, and myostatin, appear to play a crucial role in IR. Skeletal muscle can also become a target of obesity-induced and IR-induced inflammation. In the correlation between muscle, IR, and inflammation, the role of infiltration of the immune cells and the microvasculature may also be considered. It remains unclear which exercise approach is the best; however, combining aerobic exercise with resistance training seems to be the most effective strategy for managing IR, with high-intensity activities offering superior metabolic benefits and long-term adherence. Encouraging daily participation in enjoyable and engaging exercise is key for long-term commitment and effective glucose metabolism management. Promoting physical activity in children and adolescents must be a top priority for public health, not only in terms of individual quality of life and well-being but also for community health.

The Release of Lipolytic Hormones during Various High-Intensity Interval and Moderate-Intensity Continuous Training Regimens and Their Effects on Fat Loss

To investigate the release of lipolytic hormones during various high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), and their effects on fat loss. 39 young women categorized as obese (with a body fat percentage (BFP) ≥30%) were randomly allocated to one of the following groups: all-out sprint interval training (SIT, n =10); supramaximal HIIT (HIIT120, 120%V̇O2peak, n = 10); HIIT (HIIT90, 90%V̇O2peak, n = 10), or MICT, (60%V̇O2peak, n = 9) for a twelve-week observation period consisting of 3 to 4 exercise sessions per week. Serum epinephrine (EPI) and growth hormone (GH) were measured during the 1st, 20th, and 44th training sessions. Body weight (BW), body mass index (BMI), whole-body fat mass (FM) and BFP were assessed pre- and post-intervention. Following the 1st and 20th sessions, significant increases in EPI (p < 0.05) were observed post-exercise in HIIT120 and HIIT90, but not in SIT and MICT. In the 44th session, the increased EPI was found in SIT, HIIT120, and HIIT90, but not in MICT (p < 0.05). For the GH, a significant increase was observed post-exercise in all groups in the three sessions. The increased EPI and GH returned to baselines 3 hours post-exercise. After the 12-week intervention, significant reductions in FM and BFP were found in all groups, while reductions in BW and BMI were only found in the SIT and HIIT groups. Greater reductions in FM and BFP, in comparison to MICT, were observed in the SIT and HIIT groups (p < 0.05). 12-week SIT, HIIT120, and HIIT90, in comparison to MICT, were more efficacious in fat reduction in obese women, partly benefiting from the greater release of lipolytic hormones during training sessions.

High-Intensity Interval Training Decreases Circulating HMGB1 in Individuals with Insulin Resistance; Plasma Lipidomics Identifies Associated Cardiometabolic Benefits

Background: Exercise is a fundamental primary standard of care for cardiometabolic health. Body Weight (BW) High-Intensity Interval Training (HIIT) is an effective strategy for reducing cardiometabolic markers in individuals with insulin resistance and Type-2 diabetes (T2D). High-mobility group box 1 (HMGB1), a ubiquitous nuclear factor, plays an ample role beyond an alarmin in T2D development and progression. Our group has described this novel role previously, showing the beneficial effect of whole body HMGB1 silencing in decreasing hyperglycemia in diabetic mice. In the present study we tested the hypothesis that BW-HIIT as an effective exercise training modality will decrease cardiometabolic risk with a concomitant decrease in circulating HMGB1 more prominently in insulin resistant individuals compared to non-insulin resistant individuals contrasting to what we can evidence in a preclinical murine model of insulin resistance; Methods: Human and mouse pre- and post-exercise serum/plasma samples were analyzed for Lipidomics as well as Metabolic and Cytokine Multiplex assays. Standard of care, as well as cardiometabolic parameters, was also performed in human subjects; Results: insulin resistant individuals had the most positive effect, primarily with a decrease in the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). as an index of insulin resistance as well as decreased HMGB1 post-exercise. Lipidomic analysis illustrated the highly beneficial effect of exercise training using a modified HIIT program, showing an enhanced panel of circulating lipids post-exercise exclusively in insulin resistant individuals. Plasma multiplex revealed significant translational heterogeneity in our studies with distinct metabolic hormone responses to exercise conditioning with a decrease in inflammatory markers in insulin resistant individuals; Conclusions: The current study demonstrated that 6-week BW-HIIT training improves cardiometabolic, anti-inflammatory markers, metabolic hormones, and insulin sensitivity in humans, strongly associated with decreased circulating HMGB1. Overall, these experiments reinforce the potential of HMGB1 as a marker of changes in insulin resistance and the positive effect of exercise training on insulin resistance possibly preventing the development of T2D and associated complications.

Effects of 9 Weeks of High- or Moderate-Intensity Training on Cardiorespiratory Fitness, Inhibitory Control, and Plasma Brain-Derived Neurotrophic Factor in Danish Adolescents-A Randomized Controlled Trial

PURPOSE

The primary aims of this study were to examine the effects of 9 weeks of aerobic training, comprising three 30-min sessions per week, on V̇O2max, inhibitory control, and plasma brain-derived neurotrophic factor (BDNF) levels among adolescents aged 16-19 years.

METHODS

One hundred twenty-one untrained or recreationally active adolescents from a Danish high school were enrolled in the study, with 58 females (17.8 ± 0.8 years) and 27 males (18.0 ± 0.9 years) completing it. Participants were randomly divided into three groups performing aerobic training at either moderate-intensity (MIT: 60%-70% heart rate reserve [HRR]) or high-intensity (HIT: 80%-100% HRR) or a passive control group (CON) continuing their habitual lifestyle. Both the training groups exercised for 3×30 min per week for 9 weeks using a combination of cycling and running. Before and after the intervention period maximal oxygen uptake (V̇O2max) and the primary outcomes (inhibitory control measured by a modified flanker task, and resting plasma levels of BDNF) were evaluated.

RESULTS

After the intervention period, the HIT group demonstrated a larger increase in V̇O2max compared to both the CON and MIT groups, while no significant effects were observed on inhibitory control or plasma BDNF levels in any training group. However, compared to the CON group, the HIT group exhibited a tendency for greater improvement in the flanker interference score (accuracy), attributable to enhanced accuracy on the incongruent stimuli from pre to post.

CONCLUSION

Aerobic training in adolescents increased cardiorespiratory fitness in an intensity-dependent manner, but no clear effects were observed on neither inhibitory control nor resting plasma BDNF levels.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02075944.

Effectiveness of high intensity and sprint interval training on metabolic biomarkers, body composition, and physical fitness in adolescents: randomized controlled trial

Objective

The aim of this study was to evaluate the effect of HIIT and SIT programmes on body composition, blood pressure, lipid profile, glucose, cardiorespiratory fitness, and strength of adolescents and to compare the effect between those different protocols.

Methods

Sixty adolescents were recruited from a high school and were randomly placed into three groups. SIT and HIIT undertook a training for 8 weeks, twice a week, for 12 min per session, during their Physical Education lessons. SIT group performed 6 sets of 60 s of work (90-95%HRmax) / 60 s of rest (50-55%HRmax), and HIIT group performed 3 sets of 2 min of work (80-85%HRmax) / 2 min of rest (50-55%HRmax).

Results

After adjustment by sex, both experimental groups exhibited a significant reduction in fat mass (p < 0.01), and trunk fat mass (p < 0.01), as well as a significant increase in lean mass (p = 0.01; <0.01), hand-grip strength (p < 0.01) and standing long jump (p = 0.05-0.04, respectively). In addition, HIIT showed a significant (p < 0.05) improvement in blood pressure, diastolic blood pressure, heart rate and VO2max, and a tendency toward a significant reduction in low density lipoprotein.

Conclusion

The implementation of a HIIT protocol within high school Physical Education sessions, maintained for 8 weeks, at a rate of 3 sets of 2 min of work (80-85% RHR)/2 min of rest (50-55% RHR) generated adaptations such as improved fitness condition, changes in body composition, and improvements in blood parameters and blood pressure. However, the group of adolescents who performed SIT, shorter but more intense sets, did not experience as many benefits.

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.

Cardiorespiratory and Muscular Fitness in Children and Adolescents with Obesity

PURPOSE OF REVIEW

Examine the current state of literature related to the impact of obesity in children and adolescents on health-related physical fitness and the resultant cardiometabolic disease risk.

RECENT FINDINGS

Cardiorespiratory fitness of children and adolescents has declined over the past few decades which corresponds with an increase in obesity rates. Children with obesity are more likely to have low cardiorespiratory fitness which is associated with higher cardiometabolic disease risk and poorer mental health. The impact of obesity on muscular fitness in children and adolescents is more difficult to ascertain, but in general measures of physical function are lower in children with obesity which has also been associated with higher cardiometabolic disease risk. Components of health-related physical fitness are trending negatively in children and adolescents and appear to be related to the increase in prevalence of obesity. The resultant cardiometabolic disease risk has also risen which suggests a greater disease burden in the future. These disparaging findings highlight the need for aggressive interventions to improve physical fitness in children and adolescents.

Eight weeks of high-intensity interval vs. sprint interval training effects on overweight and obese adolescents carried out during the cool-down period of physical education classes: randomized controlled trial

Objective

The aim of this study was to evaluate the effect of sprint interval training (SIT) and [high intensive interval training (HIIT)] carried out during the cool-down period of the physical education classes on body composition, blood pressure variables (BP) and pulse rate (PR), and cardiorespiratory fitness of adolescents who are overweight and obese, and to compare the differences in enjoyment in response to SIT vs. HIIT.

Methods

For this randomized controlled trial, forty-five adolescents were recruited from a high school and were randomly placed into three groups. SIT and HIIT trained for 8 weeks, twice a week, for 12 min/session. Experimental group (EG) 3 was the control, and they maintained their regular physical education class schedule. The SIT group performed 6 sets of 60 s of work (90-95%HRmax) / 60 s of rest (50-55%HRmax), and the HIIT group performed 3 sets of 2 min of work (80-85%HRmax) / 2 min of rest (50-55%HRmax).

Results

Both experimental groups showed a significant improvement in fat mass (FM) (%) and trunk FM (kg). In addition, EG2 reported a significance improvement in lean mass (kg), blood pressure BP (mmHG), systolic blood pressure (SBP) (mmHg), diastolic blood pressure (DBP) (mmHg), PR (bpm), and VO2max (ml/kg/min).

Conclusion

The present study found that a HIIT protocol performed during the cool-down period of the physical education classes generated adaptations such as improvement in body composition, BP variables and PR, and cardiorespiratory fitness, in overweight and obese adolescents. In contrast, the group of overweight and obese adolescents who performed SIT showed limited benefits, with changes in fat mass only.

A systematic review and cluster analysis approach of 103 studies of high-intensity interval training on cardiorespiratory fitness

AIMS

This study aims to systematically review the systematic reviews and meta-analyses examining the effect of high-intensity interval training (HIIT) protocols on improving cardiorespiratory fitness (CRF) and to characterize the main patterns of HIIT modalities using clustering statistical procedures to examine their potential differences on improving CRF. Finally, we aimed to develop a comprehensive guideline for reporting HIIT protocols.

METHODS AND RESULTS

A systematic review was conducted on PubMed and Web of Science from their inception to 31 October 2022 for systematic reviews and meta-analysis aimed at assessing the effect of HIIT on CRF in the entire study population. The Assessment of Multiple Systematic Reviews 2 tool was used to evaluate the risk of bias of each review. Additionally, a principal component analysis testing the data adequacy for the factor solution through the Kaiser-Meyer-Olkin procedure test was conducted. Once the number of factors was identified, in order to identify data patterns according to the main characteristics of the HIIT protocols, a two-step cluster analysis was conducted. Nineteen systematic reviews and/or meta-analyses comprising 103 studies were included. Clustering of systematic reviews and meta-analyses identified three HIIT modalities ('HIIT-normal mixed', 'HIIT-long running', and 'HIIT-short cycling') underlying the interventions across the included studies. Similar effectiveness in increasing CRF among the three HIIT modalities was observed. Subgroup analyses showed no significant differences in CRF by sex, weight status, study design, and baseline physical activity level (P > 0.05), but differences were observed by age group, and exercise intensity indicator was used in the HIIT programmes (P < 0.05).

CONCLUSION

All three HIIT modalities produced significant improvements of CRF, although some modalities showed greater changes for some specific age groups or intensity indicators.

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.

Effects of combined training or moderate intensity continuous training during a 3-week multidisciplinary body weight reduction program on cardiorespiratory fitness, body composition, and substrate oxidation rate in adolescents with obesity

This study aimed to investigate the effects of combined training (COMB, a combination of moderate-intensity continuous training-MICT and high-intensity interval training-HIIT) vs. continuous MICT administered during a 3-week in-hospital body weight reduction program (BWRP) on body composition, physical capacities, and substrate oxidation in adolescents with obesity. The 3-week in-hospital BWRP entailed moderate energy restriction, nutritional education, psychological counseling, and two different protocols of physical exercise. Twenty-one male adolescents with obesity (mean age: 16.1 ± 1.5 years; mean body mass index [BMI] 37.8 ± 4.5 kg m-2) participated in this randomized control trial study (n:10 for COMB, n:11 MICT), attending ~ 30 training sessions. The COMB group performed 3 repetitions of 2 min at 95% of peak oxygen uptake (V'O2 peak) (e.g., HIIT ≤ 20%), followed by 30 min at 60% of V'O2 peak (e.g., MICT ≥ 80%). Body composition, V'O2 peak, basal metabolic rate (BMR), energy expenditure, and substrate oxidation rate were measured during the first week (W0) and at the end of three weeks of training (W3). The two training programs were equivalent in caloric expenditure. At W3, body mass (BM) and fat mass (FM) decreased significantly in both groups, although the decrease in BM was significantly greater in the MICT group than in the COMB group (BM: - 5.0 ± 1.2 vs. - 8.4 ± 1.5, P < 0.05; FM: - 4.3 ± 3.0 vs. - 4.2 ± 1.9 kg, P < 0.05). V'O2 peak increased only in the COMB by a mean of 0.28 ± 0.22 L min-1 (P < 0.05). The maximal fat oxidation rate (MFO) increased only in the COMB group by 0.04 ± 0.03 g min-1 (P < 0.05). COMB training represents a viable alternative to MICT for improving anthropometric characteristics, physical capacities, and MFO in adolescents with obesity during a 3-week in-hospital BWRP.

Accelerometer-Derived Intensity Thresholds Are Equivalent to Standard Ventilatory Thresholds in Incremental Running Exercise

Accelerometer cut-points are commonly used to prescribe the amount of physical activity, but this approach includes no individual performance measures. As running kinetics change with intensity, acceleration measurements may provide more individual information. Therefore, the aim was to determine two intensity thresholds from accelerometer measures. A total of 33 participants performed a maximal incremental running test with spirometric and acceleration (Axivity AX3) measures at the left and right tibia. Ventilatory equivalents (VE/VO2, VE/VCO2) were used to determine a first and second ventilatory threshold (VT1/VT2). A first and second accelerometer threshold (ACT1/ACT2) were determined within the same regions of interest from vector magnitude (|v| = √(ax2 + ay2 + az2). Accelerometer data from the tibia presented a three-phase increase with increasing speed. Speed at VT1/VT2 (7.82 ± 0.39/10.91 ± 0.87 km/h) was slightly but significantly lower compared to the speed at ACT1/ACT2 from the left (7.71 ± 0.35/10.62 ± 0.72 km/h) and right leg (7.79 ± 0.33/10.74 ± 0.77 km/h). Correlation analysis revealed a strong relationship between speed at thresholds determined from spriometric data or accelerations (r = 0.98; p < 0.001). It is therefore possible to determine accelerometer thresholds from tibia placement during a maximal incremental running test comparable to standard ventilatory thresholds.

The effects of exercise training on insulin resistance in children and adolescents with overweight or obesity: a systematic review and meta-analysis

Aim

The aim of present meta-analysis was to determine the effects of exercise training (Exe) on insulin resistance (IR) and body weight in children and adolescents with overweight or obesity.

Methods

PubMed, Web of Science, and Scopus were searched for original articles, published through October 2022 that included exercise versus control interventions on fasting glucose, insulin, HOMA-IR, and body weight outcomes in children and adolescents with overweight or obesity. Standardized mean differences (SMD) for fasting insulin, and weighted mean differences (WMD) for fasting glucose, HOMA-IR, body weight (BW), and 95% confidence intervals were determined using random effects models.

Results

Thirty-five studies comprising 1,550 children and adolescents with overweight and obesity were included in the present meta-analysis. Exercise training reduced fasting glucose (WMD=-2.52 mg/dL, p=0.001), fasting insulin (SMD=-0.77, p=0.001), HOMA-IR (WMD=-0.82, p=0.001), and BW (WMD=-1.51 kg, p=0.001), as compared to a control. Subgroup analyses showed that biological sex, intervention duration, type of exercise training, BMI percentile, and health status (with or without diagnosed condition), were sources of heterogeneity.

Conclusion

Exercise training is effective for lowering fasting glucose, fasting insulin, HOMA-IR, and BW in children and adolescents with overweight or obesity and could provide an important strategy for controlling IR and related factors. With clear evidence for the effectiveness of exercise interventions in this vulnerable population, it is important to determine effective approaches for increasing exercise training in children and adolescents with overweight or obesity.

Prescription and Effects of Cardiorespiratory Training in Individuals with Intellectual Disability: A Systematic Review

This study aims to systematize effects of cardiorespiratory training (CT) programs in individuals with intellectual disability (ID) and identifying the fundamental and structuring aspects for the prescription of CT. This systematic review was carried out through four databases (Pubmed, Web of Science, Scopus, and SPORTDiscus), considering data from the period between 2013 and 2022. From 257 studies, 12 studies were included in this systematic review. Three studies used interval CT, while seven used continuous CT. Seven were carried out in the population with Down syndrome, while only three were carried out with participants with ID. The CT programs had the following characteristics: duration of 8 to 12 weeks, weekly frequency of three sessions, for 20 to 60 min, the intensity of 50% to 80% of maximal heart rate or 70% to 80% of peak oxygen consumption, using an ergometer cycle or an outdoor walking. The studies reported improvements in cardiorespiratory function, lipid, hemodynamic and metabolic profile, body composition, and neuromuscular and cognitive capacity. This review presents characteristics and recommendations that technicians can follow when structuring, prescribing, and implementing CT programs to individuals with ID.

VO2max (VO2peak) in elite athletes under high-intensity interval training: A meta-analysis

Consensus is lacking regarding whether high-intensity interval training (HIIT) effectively improves VO₂max (VO₂peak) in elite athletes (Athlete must be involved in regular competition at the national level). This meta-analysis compared the effects of HIIT and conventional training methods (continuous training, repeated-sprint training, high volume low-intensity training, high-intensity continuous running, sprint-interval training, moderate-intensity continuous training)on VO₂max in elite athletes. Nine studies were included, comprising 176 elite athletes (80 female). Compared to that with conventional training, VO₂max was significantly increased after HIIT (overall: 0.58 [0.30, 0.87], I² = 0.49, P = 0.03; males: 0.41 [0.06, 0.76], I² = 0%, P = 0.89). VO₂max had positive training effects when the HIIT recovery period had an interval time ≥2 min (0.44 [0.03, 0.84], I² = 0%, P = 0.99) and recovery phase intensity ≤40% (0.38 [0.05, 0.71], I² = 0%, P = 0.96). Thus, HIIT shows superiority over conventional training methods in improving VO₂max, promoting aerobic capacity, in elite athletes.

Associations between cardiorespiratory fitness and cardiometabolic risk factors in children and adolescents with obesity

It is unclear if associations between cardiorespiratory fitness (CRF) and cardiometabolic risk factors are independent of degree of obesity, in children with obesity. The aim of this cross-sectional study on 151 children (36.4% girls), 9-17 years, from a Swedish obesity clinic, was to investigate associations between CRF and cardiometabolic risk factors, adjusted for body mass index standard deviation score (BMI SDS), in children with obesity. CRF was objectively assessed with the Åstrand-Rhyming submaximal cycle ergometer test, and blood samples (n = 96) and blood pressure (BP) (n = 84) according to clinical routine. Obesity specific reference values for CRF were used to create CRF levels. CRF was inversely associated with high-sensitivity C-reactive protein (hs-CRP), independent of BMI SDS, age, sex, and height. The inverse associations between CRF and diastolic BP did not remain significant when adjusted for BMI SDS. CRF and high-density lipoprotein cholesterol became inversely associated when adjusted for BMI SDS. Independent of degree of obesity, lower CRF is associated with higher levels of hs-CRP, as a biomarker of inflammation, in children with obesity and regular assessment of CRF should be encouraged. Future research in children with obesity should investigate if low-grade inflammation decreases when CRF is improved.

Time-dependent Effects of Moderate- and High-intensity Exercises on Myocardial Transcriptomics

The heart is a highly adaptable organ that responds to changes in functional requirements due to exposure to internal and external stimuli. Physical exercise has unique stimulatory effects on the myocardium in both healthy individuals and those with health disorders, where the effects are primarily determined by the intensity and recovery time of exercise. We investigated the time-dependent effects of different exercise intensities on myocardial transcriptional expression in rats. Moderate intensity exercise induced more differentially expressed genes in the myocardium than high intensity exercise, while 16 differentially expressed genes were down-regulated by moderate intensity exercise but up-regulated by high intensity exercise at 12 h post- exercise. Both Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis indicated that moderate intensity exercise specifically regulated gene expression related to heart adaptation, energy metabolism, and oxidative stress, while high intensity exercise specifically regulated gene expression related to immunity, inflammation, and apoptosis. Moreover, there was increased expression of Tbx5, Casq1, Igsf1, and Ddah1 at all time points after moderate intensity exercise, while there was increased expression of Card9 at all time points after high intensity exercise. Our study provides a better understanding of the intensity dependent effects of physical exercise of the molecular mechanisms of cardiac adaptation to physical exercise.

A Meta-Analysis of High-Intensity Interval Training on Glycolipid Metabolism in Children With Metabolic Disorders

Objective

Metabolic disorders are common among children and adolescents with obesity and are associated with insulin resistance, hyperlipidemia, hypertension, and other cardiovascular risk factors. High-intensity interval training (HIIT) is a time-efficient method to improve cardiometabolic health. We performed a meta-analysis to determine the effects of HIIT on glycolipid metabolism in children with metabolic disorders.

Methods

Meta-analyses were conducted to determine the effect of HIIT on glycolipid metabolism markers. Subgroup analysis with potential moderators was explored [i.e., training intensity standard and work/rest time ratio (WRR)].

Results

Eighteen trials involving 538 participants were included. HIIT showed positive effects on glycolipid metabolism, such as triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), blood glucose (BG), blood insulin (BI), and homeostasis model assessment (HOMA)-IR, when compared to the non-training control group (CON); in addition to BG (p = 0.257), the combined results of other indicators have high heterogeneity (p = 0.000). HIIT showed no superior effects when compared to moderate-intensity training (MIT). Subgroup analysis demonstrated that HIIT protocol with a WRR of 1:1 was superior to MIT for reducing TG and LDL-C and used %maximal aerobic speed (MAS) as the exercise intensity was superior to MIT for reducing TG. HIIT protocol used %heart rate (HR) as the exercise intensity was superior to MIT for increasing HDL-C, decreasing BI, and HOMA-IR.

Conclusion

HIIT improved glycolipid metabolism in children with metabolic disorders. WRR and training intensity can affect the intervention effects of HIIT.

Systematic Review Registration

[https://www.crd.york.ac.uk/], identifier [CRD42021291473].

Effects of aerobic exercise combined with resistance training on health-related physical fitness in adolescents: A randomized controlled trial

Background

/Objective: This study aimed to compare the effects of two combined training methods on health-related physical fitness components in adolescents.

Methods

Seventy-six adolescents (16.1 ± 1.1 years, n = 44 female) were randomized into groups of moderate-intensity continuous training combined with resistance training (MICT + RT), high-intensity interval training combined with resistance training (HIIT + RT), or Control. The training sessions were performed twice weekly for 12 weeks. The health-related physical fitness components evaluated were: body composition, muscular and cardiorespiratory fitness.

Results

The intervention groups had a significant reduction in body fat percentage and improvement in abdominal repetitions and VO_2peak after 12 weeks of combined exercise program (p < 0.001). Intervention effects were found to significantly reduce body fat percentage for the MICT + RT and HIIT + RT groups compared to the control group (mean difference: −3.8; 95% CI: −6.2; −1 0.3; mean difference: −4.7; 95%CI: −7.1; −2.3, respectively). For muscle fitness, significant effects of the intervention were found in increasing the number of abdominal repetitions favoring the MICT + RT group compared to the control group (mean difference: 9.5; 95% CI: 4.4; 14.7) and HIIT + RT compared to the control group (mean difference: 14.1; 95% CI 9; 19.3). For cardiorespiratory fitness, significant effects of the intervention on improving VO_2peak were found in the experimental groups (MICT + RT vs Control group: mean difference: 4.4; 95% CI: 2.2; 6.6; and HIIT + RT vs. Control group: mean difference: 5.5, 95% CI: 3.3; 7.7).

Conclusion

The results suggest that 12 weeks of training using MCIT + RT or HIIT + RT showed a similar effect for health-related physical fitness components in adolescents.