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

Cardiorespiratory Fitness Is an Indicator of Arterial Stiffness and Aortic Blood Pressure in Healthy Adolescents

Background/Objectives: We aimed to investigate the influence of cardiorespiratory fitness (CRF) and body composition on arterial stiffness. Methods: Carotid-to-femoral pulse wave velocity (cfPWV) and aortic systolic (ASBP) and diastolic (ADBP) blood pressure were compared between upper and lower tertiles of oxygen consumption at the aerobic threshold (VO2AerT), peak oxygen consumption (VO2peak), percentage of fat mass (FM%), and body mass index (BMI) in sixty adolescents (30 males and 30 females, 14.9 ± 2.1 years old). A stepwise multivariable linear regression analysis was performed to investigate the independent associations between VO2AerT and VO2peak and cfPWV, and between BMI and FM% and cfPWV with adjustments for age, sex, ASBP, and ADBP. Results: cfPWV and ADBP were lower in the second and third VO2AerT tertiles compared to the first tertile (cfPWV, 4.7 ± 0.5 and 4.7 ± 0.5 vs. 5.3 ± 0.8 m/s, p < 0.01; ADBP, 62 ± 7 and 62 ± 7 vs. 70 ± 8 mmHg, p < 0.01). ASBP was lower in the third VO2AerT tertile compared to the first tertile (94 ± 7 vs. 101 ± 12 mmHg, p = 0.05). ADBP was lower in the second VO2peak tertile compared to the first tertile (62 ± 7 vs. 68 ± 9 mmHg, p = 0.03). ASBP was lower in the first and second BMI tertiles compared to the third tertile (95 ± 8 and 95 ± 7 vs. 102 ± 11 mmHg, p = 0.02). The eight-variable model significantly contributed to the variance of cfPWV (F(8, 51) = 7.450, p < 0.01), accounting for 47% of the variance. Individually, age (p < 0.05) and ADBP (p < 0.01) significantly predicted cfPWV. Conclusions: Submaximal indicators of CRF such as VO2AerT should be considered as a part of the risk stratification of cardiovascular disease in healthy adolescents.

Mild Dehydration Triggered by Exercise Reduces Cognitive Performance in Children, But Does Not Affect Their Motor Skills

OBJECTIVE

Children face the risk of dehydration in varying amounts during the day due to reasons such as physical activity, sweating, eating salty foods and drinking carbonated beverages. It is assumed that dehydration can lead to impaired motor skills and cognitive performance since it affects brain function. However, inconsistencies in study results, test times and problems caused by heat stress make new research mandatory. In our research, we examined the effects of exercise-induced mild dehydration on motor skills and cognitive performance in active/sedentary boys who do/do not do regular physical activities in their daily lives.

METHODS

The study included 112 boys who do regular physical activity (n:57; 12.40 ± 0.49age) and sedentary (n:55; 12.49 ± 0.50age). The children were given a 12-h hydration program. Mild dehydration was created by giving exercises after hydration measurements. In case of hydration and mild dehydration, Bruininks-Oseretsky Motor Proficiency and d2 attention test were applied to the children. For comparison, Repeated Measures ANOVA and Bonferroni post-hoc test was performed at the second level.

RESULTS

According to the hydration and mild dehydration comparison results, there was no difference in total score of Fine Motor Skill Sensitivity, Fine Motor Skill Integration, Hand Dexterity and Bidirectional Coordination, Balance, Running Speed and Agility, Hand-Arm Coordination, Strength, and BOT-2 in children. There was a decrease in both groups in terms of Focused Attention, Processing Speed, Accuracy, Concentration Performance and Attention Span.

CONCLUSION

As a result, mild dehydration is associated with daily physical activity in children (physical education classes, etc.) or it can easily occur due to food/beverage preferences. It may affect children's performance of school curriculum and extracurricular activities. It shows that maintaining optimal hydration is important.

Association between physical activity and cardiovascular parameters in 7-year-old children: a Chinese cross-sectional study

INTRODUCTION

Physical activity (PA) is believed to play an important part in many aspects during childhood and adolescence, especially cardiorespiratory fitness and cardiometabolic health. However, whether different levels of PA in daily life influence the structure or function of heart in school-aged children remains unknown. We aimed to investigate the association between PA and cardiovascular parameters in 7-year-old children.

METHODS

Follow-up data from the Shanghai Prenatal Cohort Study and the Shanghai Birth Cohort was analyzed. Perinatal information including both maternal and offspring datum was recorded. A refined questionnaire was used to evaluate the frequency and duration of children's PA levels. Blood pressure, echocardiography, and anthropometry assessment were conducted during the follow-up of 7-year-old children.

RESULTS

Overall, high PA level was associated with higher left ventricle posterior wall thickness in diastole (LVPWd, β coefficient: 0.36, 95% CI: 0.12, 0.61), higher left ventricle mass index (LVMI, β = 0.28, 95% CI: 0.07, 0.48), mitral E/a ratio (β = 0.47, 95% CI: 0.22, 0.71) and slower heart rate (β = -0.32, 95% CI: -0.57, -0.07), compared to low PA level. Medium PA level was associated with lower diastolic blood pressure (DBP, β = -0.18, 95% CI: -0.35, -0.01). In subgroup analysis, increased relative wall thickness (RWT) was found in high PA level boys (β = 0.36, 95% CI: 0.05, 0.67), and systolic blood pressure (SBP) showed a significant decrease in high PA level girls (β = -0.42, 95% CI: -0.78, -0.06).

CONCLUSIONS

This study suggested non-athlete children having higher PA level were associated with thicker left ventricle (LV) walls and better LV diastolic function, as well as slower heart rate and DBP at the age of 7. Furthermore, disparity in the association between PA level with morphological heart patterns and blood pressure existed in different sex category.

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.

Different humidity environments do not affect the subsequent exercise ability of college football players after aerobic high-intensity interval training

Previous studies have explored the effect of differing heat and relative humidity (RH) environments on the performance of multiple anaerobic high-intensity interval training (HIIT). Still, its impact on physiological responses and performance following aerobic HIIT has not been well studied. This study examined the effects of differing RH environments on physiological responses and performance in college football players following HIIT. Twelve college football completed HIIT under four different environmental conditions: (1) 25 °C/20% RH (Control group); (2) 35 °C/20% RH (H20 group); (3) 35 °C/40% RH (H40 group); (4) 35 °C/80% RH (H80 group). The heart rate (HR), mean arterial pressure (MAP), lactate, tympanic temperature (TT), skin temperature (TS), thermal sensation (TS), and rating of perceived exertion (RPE) were recorded continuously throughout the exercise. The heart rate variability (HRV): including root mean squared differences of the standard deviation (RMSSD)、standard deviation differences of the standard deviation (SDNN)、high frequency (HF), low frequency (LF), squat jump height (SJH), cycling time to exhaustion (TTE), and sweat rate (SR) were monitored pre-exercise and post-exercise. The HR, MAP, lactate, TT, Ts, TS, and RPE in the 4 groups showed a trend of rapid increase, then decreased gradually. There was no significant difference in HR, MAP, TT, or RPE between the 4 groups at the same time point (p > 0.05), in addition to this, when compared to the C group, the lactate, Ts, TS in the other 3 groups significant differences were observed at the corresponding time points (p < 0.05). The RMSSD, SDNN, HF, and LF levels in the 4 groups before exercise were not significantly different. The RMSSD and HF in the H40 and H80 groups were significantly decreased and other HRV indicators showed no significant difference after exercise. In sports performance measurement, the SJH and TTE were significantly decreased, but there was no significant difference in the 4 groups. The SR was no significant difference in the 4 groups after exercise. In conclusion, heat and humidity environments elicited generally greater physiological effects compared with the normal environment but did not affect sports performance in college football players.

Effects of different exercise interventions on cardiopulmonary function in male tobacco-dependent college students

This study investigated the effects of different exercise interventions on cardiopulmonary function in male tobacco-dependent college students. Forty-five male tobacco-dependent college students were recruited as the tobacco-dependent (TB) group, and 45 non-tobacco-dependent college students were recruited as the control group. The TB group was randomly assigned to three subgroups: non-exercise (NE), high-intensity interval training (HIIT), and moderate-intensity continuous training (MICT). The HIIT and MICT groups underwent a 10-week exercise training, while the NE group received no intervention. Cardiac parameters, including maximal oxygen uptake (VO2max), heart rate max (HRmax), and heart rate reserve (HRR), and pulmonary indicators, including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), vital capacity (VC), maximum ventilation volume (MVV), and peak expiratory flow (PEF) were investigated. The results showed that the TB group had significantly lower cardiopulmonary function than the control group. The degree of tobacco dependence was negatively correlated with VO2max, FVC, FEV1, FEV1/FVC, and MVV. Furthermore, both HIIT and MICT training improved cardiopulmonary function. HIIT training exhibited superior efficacy compared to MICT in improving HRmax, HRR, FVC, FEV1, FEV1/FVC, and PEF. In conclusion, tobacco dependence adversely affects cardiopulmonary function in male college students. Both HIIT and MICT effectively improved cardiopulmonary function, with HIIT showing superior efficacy.

Changes in Muscle Mass and Strength in Adolescents Following High-Intensity Functional Training with Bodyweight Resistance Exercises in Physical Education Lessons

(1) Background: The growing prevalence of obesity, diabetes, hypertension, and declining physical fitness among children and adolescents due to sedentary lifestyles has increased attention toward preventive intervention to tackle this issue. This study investigated the age-related effects of high-intensity functional training (HIFT), based on bodyweight resistance exercises conducted during physical education lessons, on muscle mass and strength improvement. (2) Methods: Adolescent males (n = 116) were allocated to four HIFT experimental groups (EGs) and four standard physical education program control groups (CGs) according to age (15, 16, 17, and 18 years [y]). The changes in muscle mass (absolute and relative to height [SMI]), hand-grip strength (HGS), sit-ups (SUs), and standing broad jump (SBJ) were analyzed using two-way analysis of variance (ANOVA) with Bonferroni tests. (3) Results: HIFT significantly increased muscle mass and scores in all strength tests (p < 0.01), while chronological age was significant for HGS (p < 0.01). Interactions between HIFT and chronological age categories were observed for HGS (p = 0.01) and SBJ (p < 0.03). Detailed post hoc tests revealed improvement in muscle mass across all chronological age categories for both approaches (p < 0.05). The 18y-EG group improved HGS over their control peers (p < 0.01), the EG groups significantly improved their SU results (p < 0.01), and SBJ improved in the 15y-EG and 18y-EG groups compared to their control (p < 0.01). (4) Conclusions: This research highlights the effectiveness of a school-based HIFT program in promoting muscle mass gains and enhancing muscle strength among adolescents. The findings offer valuable insights for implementing bodyweight exercises during physical education classes.

Muscular fitness profiles in relation to the response in body fat during school-based high-intensity intervention

BACKGROUND

We aimed to assess the equivalence of the muscular fitness (MF) between body fat percentage (BFP) responders (RsBFP) and non-responders (NRsBFP) to school-based high-intensity interval training (HIIT). Adolescents aged 16 (N.=73, 42.5% of males) were identified as RsBFP (N.=45) or NRsBFP (N.=28). MF was assessed based on hand strength (HS), abdominal muscle strength (ABS), and leg power (VJ).

METHODS

Profile analysis showed distinct patterns of MF changes in both response categories. Despite the presence of parallelism (Wilks' Λ=0.979, Pillai's V=0.212, P=0.473), a gradient of increasing changes (HS-ABS-VJ) was found in the RsBFP, while a gradient of decreasing changes was shown in the NRsBFP, and a significant level of inequality (F(1,71)=7.823, P=0.047, partial eta-squared [η2p] 0.041).

RESULTS

One-way analysis showed a significant and moderate effect on VJ (F(1,71)=7.080, P=0.010, η2P=0.091), a close to significant effect on ABS (F(1,71)=3.300, P=0.074, η2P=0.044) and lack of an effect on HS (F(1,71)=0.699, P=0.406, η2P=0.010). The test of equal means across the condition categories (separately for RsBFP and NRsBFP) indicated that there was no multivariate statistically significant within-group effect (F(2, 70)=0.517, P=0.599).

CONCLUSIONS

The findings may help teachers assess the potential and indirect changes in muscle performance after employing a body weight intervention (based on the HIIT program). A more targeted approach to treating adolescents with excessive BF, in parallel with improving MF, can be individually tailored.

Association between time of assessment within a school year and physical fitness of primary school children

The dissociation of effects of age, time of assessment and cohort is a well-known challenge in developmental science. We examined effects of time of assessment in the school year on children's physical fitness using data from 75,362 German third-graders from seven cohorts. Children were tested once either in the first or second school term of third grade. Tests examined cardiorespiratory endurance (6-min run), coordination (star-run), speed (20-m sprint), lower (standing long jump) and upper (ball-push test) limbs muscle power, and flexibility (stand-and-reach test). We estimated the effect of time of assessment using a regression discontinuity design specified in a linear mixed model with random factors child and school and adjusted for age, sex, and cohort effects. Coordination, speed, and upper limbs muscle power were better in second compared to first school term, with boys exhibiting a larger increase of upper limbs muscle power than girls. There was no evidence for changes in cardiorespiratory endurance, lower limbs muscle power, and flexibility between assessments. Previously reported age and sex effects as well as secular fitness trends were replicated. There is thus evidence for improvement of some physical fitness components beyond age and cohort effects that presumably reflects the benefit of physical activity in physical education and other settings. Effects of assessment time should be taken into consideration in performance-based grading or norm-based selection of children.

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 5-Week Guided Active Play Program Modulates Skin Microvascular Reactivity in Healthy Children

PURPOSE

Children's poor levels of physical activity (PA) participation and early-onset vascular aging are identified as global health challenges. Children's guided activity play (GAP)-based PA programs have emerged as effective strategies to improve cardiovascular risk factors and health-related fitness. This study proposes to investigate whether GAP improves children's cutaneous microvascular reactivity and health-related fitness.

METHODS

Children's (n = 18; 9.8 [1.5] y) PA during a 5-week (4 d/wk; 1 h/d) GAP program was assessed (accelerometry) with preassessments and postassessments for anthropometric, musculoskeletal fitness, blood pressure, estimated aerobic power, and cutaneous microvascular reactivity.

RESULTS

PA averaged 556 (132) kcal·week-1 at 34.7% (7.5%) time at moderate to vigorous intensity. Resting heart rate (-9.5%) and diastolic blood pressure (-7.8%) were reduced without changes in health-related fitness indices. Cutaneous microvascular reactivity to sodium nitroprusside iontophoresis increased the average perfusion (+36.8%), average cutaneous vascular conductance (+30%), the area under the curve (+28.8%), and a faster rise phase (+40%) of perfusion (quadratic modeling; P ≤ .05). Chi-square and crosstabulation analysis revealed significant association between children's PA levels and sodium nitroprusside average perfusion levels, where children with PA levels ≥205.1 kcal.55 minute-1 were overrepresented in the medium/high levels of sodium nitroprusside perfusion.

CONCLUSION

A 5-week GAP modified the microvascular reactivity in children without changes in body mass, musculoskeletal fitness, or estimated aerobic power.

Health benefits of short Taichi Qigong exercise (STQE) to University Students' core strength, lower limb explosive force, cardiopulmonary endurance, and anxiety: A Quasi experiment research

BACKGROUND

College students' physical fitness has declined over the past decades. Taichi Qigong exercise offers numerous health benefits and could serve as a suitable option for them. Traditional programs, however, are time-consuming and necessitate long-term commitments. Therefore, a more cost-effective intervention is needed.

METHODS

The study enrolled a total of 31 students who actively participated in a 5-week STQE program, consisting of three 60-minute sessions per week. Physical and mental health assessments included the Plank test, vital capacity measurement, 1000/800 m run test, standing jump, and the Zung Self-Rating Scale. Data analysis was performed using SPSS.

RESULTS

Following the STQE intervention, participants showed improvement in core strength (28.1 seconds in the Plank test, P = .025) and lower limb explosive force (6.52 cm in the standing jump test, P = .011), accompanied by a decrease in anxiety levels (a reduction of 3.41 in the Zung Self-Rating Scale, P = .039). However, no significant improvements were observed in cardiopulmonary endurance, as evidenced by a non-significant increase of 237.84 mL in vital capacity (P = .134) and a non-significant reduction of 1.6 seconds in the 1000/800 m run test (P = .764).

CONCLUSION

The study suggests that the STQE program effectively improves core strength, lower limb explosive force, and reduces anxiety levels among university students.

Effects of a physical education intervention on children's physical activity and fitness: the PROFIT pilot study

BACKGROUND

Physical education classes are widely accepted as one of the most effective settings for promoting physical activity and health and have often been used to implement physical activity interventions. The aim of this pilot study was to test a physical education intervention program on physical activity levels and physical fitness in a sample of school-age children.

METHODS

Participants were a convenience sample of 50 children (34 experimental group and 16 in the comparative group) aged between 6 and 11 years old (Mean = 8.28 years). A 21-week intervention was implemented, consisting of high-intensity and physical fitness-focused exercises, in addition to a once-a-month extra class nutritional education. The following variables were evaluated before and post-intervention: physical fitness, sedentary behavior (SB), light physical activity (LPA), moderate physical activity (MVA), and vigorous physical activity (VPA). Propensity score analyses calculated the average treatment effect on the treated (ATET) within a quasi-experimental framework.

RESULTS

Physical fitness variables showed improvements after the intervention, specifically for agility (ATET = -0.67 s; p < 0.001), cardiorespiratory fitness (ATET = 89.27 m; p = 0.045), lower limbs power (ATET = 4.47 centimeters; p = 0.025), and speed (ATET = -1.06 s; p < 0.001). For physical activity and SB levels, there were no improvements after intervention implementation.

CONCLUSION

The intervention program showed preliminary effectiveness to improve physical fitness of children, but not SB nor physical activity.

Effects of high-intensity interval training on strength, speed, and endurance performance among racket sports players: A systematic review

This study aims to present a critical review of the existing literature on the effects of High-Intensity Interval Training (HIIT) on strength, speed, and endurance performance among racket sports athletes. This study conducted a systematic literature review by PRISMA guidelines. Various well-known academic and scientific databases were used for research collection, including PubMed, EBSCOhost, Scopus, Web of Science, and Google Scholar. Out of 27 relevant studies, 10 were selected for inclusion in this systematic review, all meeting the required inclusion criteria. The quality of each study was assessed using the PEDro scale, with scores ranging from 3 to 5 for the selected studies. HIIT was found to improve racket players' VO2 max (maximum oxygen uptake), running and repetitive sprint performance, jumping performance, and hitting speed during play. Current findings indicate that HIIT can significantly benefit athletic performance. Long-term HIIT allows athletes to enhance their power while improving crucial variables related to both aerobic and anaerobic endurance. This anaerobic endurance and explosive power type is particularly vital for racket sports players. For example, athletes in table tennis and badminton must exert maximum effort during high-intensity middle and back-court play. Racket athletes also need to maintain a stable state while preserving ball speed and positioning, and must quickly recover to prepare for the next rally. This training mechanism can assist athletes in honing their skills and achieving more efficient hitting quality. Therefore, this paper recommends that racket sports athletes incorporate HIIT into their regular training routines. The suggested frequency is three times per week, with each training session lasting 30-40 minutes, and a total duration of six to eight weeks. Trial registration. Systematic Review Registration: [https://inplasy.com/], identififier[INPLASY20230080].

Moving beyond moderate-to-vigorous physical activity: the role of light physical activity during adolescence

Regular physical activity is an important component of a healthy lifestyle for young people. However, an estimated 80% of adolescents globally are insufficiently active. Traditionally, health benefits were attributed only to physical activity of at least moderate intensity, and recommendations focused on achieving a threshold of moderate-to-vigorous physical activity, without consideration of other aspects of movement within the 24 h cycle. Recently, the overall daily balance of active and sedentary behaviours has gained recognition as an important determinant of health. However, the relationship between light intensity physical activity and health has not been fully explored. In this perspective paper, we discuss key challenges in defining, measuring and analysing light physical activity which have hindered the advancement of knowledge in this area. Next, we suggest three ways in which light physical activity may enhance adolescent wellbeing: firstly, by replacing sedentary behaviours to increase daily movement; secondly, by supporting the accumulation of higher intensities of physical activity; and thirdly, by providing positive experiences to facilitate lifelong engagement with physical activity. In highlighting the importance of light physical activity during adolescence, we aim to encourage critical reflection and the exploration of new approaches towards physical activity within public health and beyond.

High-intensity interval training ameliorates chronic unpredictable mild stress-induced depressive behaviors via HDAC2-BDNF signaling in the ventral hippocampus

Major depressive disorder (MDD) is a devastating psychiatric disease, and current therapies could not well meet the demand for MDD treatment. Exercise benefits mental illness, and notably, exercise has been recommended as an alternative option for MDD treatment in some countries. However, the paradigm and intensity of exercise for MDD treatment has yet to be determined. High-intensity interval training (HIIT) is a potent and time-efficient type of exercise training and has gained popularity in recent years. In this study, we exposed the mice to chronic unpredictable mild stress (CUMS) and found HIIT exerted substantial antidepressant effect. Moreover, HIIT further enhanced the antidepressant effect of fluoxetine, a classic antidepressant in the clinic, confirming the antidepressant role of HIIT. HIIT significantly reversed the CUMS-induced upregulations in HDAC2 mRNA and protein level in the ventral hippocampus. We also found HIIT rescued the CUMS-induced downregulation in the expression of brain-derived neurotrophic factor (BDNF) and HDAC2 overexpression counteracted the HIIT-induced increase in BDNF level. More importantly, both virus-mediated HDAC2 overexpression and microinfusion of TrkB-Fc, a BDNF scavenger, in the ventral hippocampus abolished the antidepressant effect of HIIT. Together, our results strongly demonstrate that HIIT attenuates depressive behaviors, probably via HDAC2-BDNF signaling pathway and reveal that HIIT may serve as an alternative option for MDD treatment.

Serum Osteocalcin, Sclerostin and Lipocalin-2 Levels in Adolescent Boys with Obesity over a 12-Week Sprint Interval Training

The aim of the study was to examine the effects of supervised cycling sprint interval training (SIT) on serum osteocalcin, lipocalin-2 and sclerostin levels, and bone mineral characteristics among obese adolescent boys. Untrained obese adolescent boys aged 13.4 ± 0.3 were assigned to either a 12-week SIT group (3 sessions/week), or a non-exercising control group who continued with their habitual everyday life. Serum osteocalcin, lipocalin-2 and sclerostin concentrations, and bone mineral values were assessed before and after intervention. After 12-week intervention, where 14 boys in both groups ended the study, there were no significant differences in serum osteokine levels between the groups after 12 weeks, while whole body bone mineral content and lower limb bone mineral density increased in the SIT group (p < 0.05). Change in body mass index was negatively correlated with the change in osteocalcin (r = -0.57; p = 0.034), and positively correlated with the change in lipocalin-2 levels (r = 0.57; p = 0.035) in the SIT group. Supervised 12-week SIT intervention improved bone mineral characteristics, but did not change osteocalcin, lipocalin-2 or sclerostin levels in adolescent boys with obesity.

The associations of physical activity, sedentary time, and sleep with V˙O2max in trained and untrained children and adolescents: A novel five-part compositional analysis

The benefits of physical activity (PA) and the negative impacts of sedentary time (SED) on both short- and long-term health in youth are well established. However, uncertainty remains about how PA and SED jointly influence maximal oxygen uptake ([Formula: see text]). Therefore, the aim of this study was to determine the joint influence of PA and SED on [Formula: see text] using compositional analyses. 176 adolescents (84 girls, 13.8 ± 1.8 years) completed an incremental ramp test and supramaximal validation bout on a cycle ergometer, with PA and SED recorded for seven consecutive days on the right hip using a ActiGraph GT3X accelerometer. Time spent in Sleep, SED, light, moderate and vigorous PA was analysed using a compositional linear regression model. Compositions with 10 minutes more time in vigorous PA (> 27.5 mins⋅day-1) compared to the average 17.5 mins⋅day-1 were associated with a + 2.9% - 11.1% higher absolute and scaled [Formula: see text] whilst compositions with less (> -10 mins⋅day-1) VPA were associated with a reduced absolute and allometrically scaled [Formula: see text] (-4.6% - 24.4%). All associations were irrespective of sex, maturity, and training status. The proportion of time spent sedentary had little impact on absolute and scaled [Formula: see text] (0.01-1.98%). These findings therefore highlight that intensity of PA may be of greater importance for increases in [Formula: see text] than reductions in SED and should be incorporated into future intervention designs.

Targeted Lipidomics and Inflammation Response to Six Weeks of Sprint Interval Training in Male Adolescents

Lipids play an important role in coordinating and regulating metabolic and inflammatory processes. Sprint interval training (SIT) is widely used to improve sports performance and health outcomes, but the current understanding of SIT-induced lipid metabolism and the corresponding systemic inflammatory status modification remains controversial and limited, especially in male adolescents. To answer these questions, twelve untrained male adolescents were recruited and underwent 6 weeks of SIT. The pre- and post-training testing included analyses of peak oxygen consumption (VO2peak), biometric data (weight and body composition), serum biochemical parameters (fasting blood glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triacylglycerol, testosterone, and cortisol), inflammatory markers, and targeted lipidomics. After the 6-week SIT, the serum C-reactive protein (CRP), interleukin (IL)-1β, IL-2, IL-4, IL-10, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β significantly decreased (p < 0.05), whereas IL-6 and IL-10/TNF-α significantly increased (p < 0.05). In addition, the targeted lipidomics revealed changes in 296 lipids, of which 33 changed significantly (p < 0.05, fold change > 1.2 or <1/1.2). The correlation analysis revealed that the changes in the inflammatory markers were closely correlated with the changes in some of the lipids, such as LPC, HexCer, and FFA. In conclusion, the 6-week SIT induced significant changes in the inflammatory markers and circulating lipid composition, offering health benefits to the population.

A Randomized Cross-Over Analysis of the 6-Minute Step Test When Administered in Different Music Listening Conditions to Healthy Young Adults

The 6-Minute Step Test (6-MST) is a simple, inexpensive field test that is increasingly used to evaluate cardiorespiratory fitness. Whether sufficient performance is revealed by this test and the effect on it of motivational factors such as music is unknown. In this cross-sectional, randomized, and crossover research design, we aimed to analyze 6-MST performance and test outcomes in different music-related auditory conditions of non-musical/non-rhythmic [NM/NR], musical/non-rhythmic [M/NR], and musical/rhythmic [M/R]). We had 38 healthy young adults (M age = 21.21, SD = 1.21 years; 60% male) complete all tests, and we measured their number of steps taken, heart rate, blood pressure, respiratory rate, peripheral oxygen saturation, perceived dyspnea, and fatigue on the modified Borg scale. We recorded individually calculated submaximal values according to heart rate reached after three tests. The number of steps increased in the M/R condition relative to other conditions (p = 0.003), and the amount of change in perceived leg fatigue was also higher in the M/R condition (p < 0.017). Despite variable test performances in different auditory conditions, we found no statistically significant difference in cardiovascular fitness and symptoms (p > 0.05). We concluded that the 6-MST is a useful tool for assessing maximum cardiac tolerance, especially if administered while listening to rhythmic music.

Effects of a High Intensity Interval Training (HIIT) Program on Anthropomorphic and Cardiometabolic Variables in School Children with Overweight and Obesity

The aim of this study was to assess the effects of a high intensity interval training (HIIT) program on anthropomorphic and cardiometabolic variables in schoolchildren with overweight and obesity. A total of 443 schoolchildren (age: 6.37 ± 0.65 years) took part in this study. The experimental group (EG; n = 295; age = 6.40 ± 0.64 years) was compound with children with overweight and obesity, whereas children with normoweight were included in the control group (CG; n = 148; 6.31 ± 0.67 years). The EG performed a training program based on HIIT two times per week for 28 weeks (56 sessions), whilst the CG performed their habitual physical education classes based on the national curriculum. Body mass index (BMI), waist circumference, body fat, ∑ 4 skinfold fat, waist to height ratio, waist circumference, and cardiometabolic risk were measured. The dependent variables were analysed by two-way analysis of covariance (ANCOVA 2 × 2). To analyse the percentage differences between groups, the chi-square test was used. P-value was set at p < 0.05. Significant differences were found in the EG in BMI, waist circumference, body fat, ∑ 4 skinfold fat, and waist to height ratio. In conclusion, an HIIT training program can be an effective tool for improving anthropomorphic variables and reducing cardiometabolic risk in schoolchildren with overweight and obesity.

A Comparative Study of Inhibition Function between High-Intensity Interval Training and Moderate-Intensity Continuous Training in Healthy People: A Systematic Review with Meta-Analysis

Meta-analysis was used to compare the effects of two interventions, high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), on inhibition in executive function in healthy people, providing some theoretical basis for exercise practice and health interventions. We searched the PubMed, Science Direct, Web Of science, Cochrane, and CNKI databases for relevant articles on the inhibition function effects of HIIT and MICT in healthy populations for the period of library construction to 15 September 2022. The basic information of the screened literature was organized and summarized using Excel. Statistical analysis of the correct rate and response time indicators of the inhibition function in the HIIT and MICT groups was performed using Review Manager 5.3 analysis software. A total of 285 subjects from 8 studies were included in this study, the number of HIIT subjects was 142, the number of MICT subjects was 143, including teenagers, young adults, and the elderly. Eight studies included response time, and four included correct rate and response time. The standardized mean difference (SMD) for correct rate inhibition function in the HIIT and MICT groups was 0.14, 95% CI (-0.18, 0.47), SMD at response time was 0.03, 95% CI (-0.20, 0.27). In addition, no significant differences were found between the two exercise modalities in either the intervention period or the population receiving the intervention. Both HIIT and MICT could improve inhibition function in healthy people, but there was no significant difference in the improvement effect between them. It is hoped that this study can provide some references for people's choice of health intervention methods and clinical practice.

Does incorporating high intensity interval training in physical education classes improve fitness outcomes of students? A cluster randomized controlled trial

The aim of this study was to determine the efficacy of a high intensity interval training (HIIT) intervention lasting 12 weeks on fitness (cardiorespiratory fitness, muscular strength, muscular endurance, power, speed, flexibility, and balance) and adiposity of 10- to 15-year-old students implemented during their physical education (PE). The focus of this study was to compare two approaches to increasing fitness level among school-aged children, one approach focusing on regular PE sessions in accordance with the curriculum and another one on regular PE classes augmented by HIIT. A cluster-randomized controlled trial was conducted (February-May 2022, Zagreb, Croatia). The total number of students across both groups was 207. General linear models were used to compare fitness and adiposity changes in both groups based on Eurofit test battery. A significant effect of the HIIT intervention was present for the 20-meter shuttle run test (p = 0.001; d = 0.31). The effect of the intervention compared to the control was estimated as an additional 181.2 m, 95 %CI (70.4 to 292.0). An additional intention-to-treat (ITT) analysis showed that the effect of the HIIT intervention on 20-meter shuttle run test remained statistically significant (p = 0.011), though the magnitude of the estimated effect was reduced from 181.2 m; SE = 55.4 to 119.6 m; SE = 46.4. Whilst it appears HIIT had the opposite of the expected effect on body fat percentiles, the effect on body composition was inconsistent. The intervention is registered at the Australian New Zealand Clinical Trials Registry (ANZCTR) [ACTRN12622000209796].

Physical fitness mediates and predicts for high blood pressure among children in relation to weight status

Background

Pediatric hypertension contributes to adulthood hypertension and target organ damage. Obesity is a well-known predictor for pediatric hypertension; however, the relationship between physical fitness and blood pressure (BP) is unclear among children. This study aimed to compare the differences in demographics, anthropometrics, and physical fitness across BP subgroups and investigate whether physical fitness was related to pediatric hypertension independent of weight status.

Methods

This quantitative, cross-sectional study investigated demographic, anthropometric, physical fitness, and BP measures among 360 healthy school-aged children. Continuous variables were compared across BP subgroups with the one-way analysis of variance. Mediation and moderation analyses were used to explore the mechanism. Multivariable regression models were used to assess independent associations for hypertension.

Results

There were 177 (49.2%), 37 (10.3%), and 146 (40.6%) children in the normotensive, elevated BP, and hypertensive subgroups, respectively. The hypertensive subgroup had higher body mass index (BMI) and waist/height ratio percentiles and performed worse in 800-m run, standing long jump (SLJ), and 1-min sit-ups than the normotensive subgroup. Furthermore, the 800-m run percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) and sit and reach percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) mediated the relationship between the BMI percentile and systolic BP percentile; the SLJ percentile was directly associated with the diastolic BP percentile (β,-0.197, 95% confidence interval,-0.298-0.097; p < 0.001). The parsimonious model of multivariable regression models revealed that the SLJ percentile (adjusted exp (β), 0.992, 95% confidence interval, 0.985-0.999; p = 0.042) and BMI percentile (adjusted exp (β), 1.024, 95% confidence interval, 1.016-1.032; p < 0.001) were two independent predictors for pediatric hypertension.

Conclusion

Physical fitness mediates the relationship between anthropometric and BP measures. The SLJ percentile is associated with pediatric hypertension independent of the BMI percentile. Proactive screening and health promotion for not only healthy weight status but also good physical fitness may be beneficial for BP control among school-aged students.

Effect of supervised sprint interval training on cardiorespiratory fitness and body composition in adolescent boys with obesity

This study examined the effect of a supervised 12-week sprint interval training (SIT) on cardiorespiratory fitness (CRF) and body composition in adolescent boys with obesity. Twenty-eight adolescents with obesity were allocated to either an intervention group (SIT) (13.1 ± 0.3 yrs; body mass index [BMI]: 30.3 ± 0.9 kg.m^-2) or a control group (CONT) (13.7 ± 0.4 yrs; BMI: 32.6 ± 1.6 kg.m^-2). The SIT group performed 4-6 × 30s "all-out" cycling bouts, interspersed with 4 min of recovery 3 days a week for 12 weeks. CRF was measured by direct peak oxygen consumption (VO₂peak) defined as VO₂peak per kg of body mass (mL.min^-1kg^-1) or by VO₂peak per kg of lean body mass (mL.min^-1LBM^-1) and body composition was assessed by dual-energy X-ray absorptiometry. SIT intervention led to a significant and large between-group difference in VO₂peak (p = 0.004; η² = 0.29). Although SIT group had a significant reduction in body fat percentage (BF%) (from 41.1 ± 1.3% to 39.2 ± 1.5%; p = 0.006), there were no between-group differences in the change of the pre- and post-measures in BF% (p = 0.067). In conclusion, 12-week SIT is effective in increasing CRF and decreasing BF% in adolescent boys with obesity.

Integrating High-Intensity Interval Training into a School Setting Improve Body Composition, Cardiorespiratory Fitness and Physical Activity in Children with Obesity: A Randomized Controlled Trial

The aim of this study was to examine the effects of school-based high-intensity interval training (HIIT) on cardiorespiratory fitness and visceral adipose tissue (VAT) in children with obesity. A total of 40 students (11.0 ± 0.6 years; 20 boys) were randomized into an intervention group (IG) and control group (CG). The IG group performed a 12-week HIIT intervention with three sessions per week. Each session included 18 min of training (three sets of eight bouts of 15 s run at 100% maximal aerobic speed (MAS) separated by eight bouts of 15 s recovery run at 50% MAS) in PE class; the CG group were instructed to continue their normal behaviors. All subjects had indices of body mass index (BMI), fat mass (FM), body fat percentage (%BF), fat free mass (FFM), VAT, and maximal oxygen uptake (VO2max) measured at baseline and post-intervention. The cooperation of students was high, and all 40 students were included in the final analysis. A significant group−time interaction was determined in body composition (p < 0.05), with a significant decrease in BM (−3.4 ± 1.4 kg, p = 0.001; η2 = 0.63), BMI (−1.7 ± 0.5, p = 0.001; η2 = 0.58), %BF (−3.3 ± 1.4, p = 0.001; η2 = 0.54), and FM (−3.2 ± 1.4 kg, p = 0.001; η2 = 0.69), and VAT (−22.4 ± 9.8 cm2; p = 0.001; η2 = 0.61) in the IG. Furthermore, VO2max exhibited a significant increase in the IG (4.5 ± 1.6 mL/kg/min, p = 0.001; η2 = 0.84) and CG groups (1.7 ± 1.1 mL/kg/min, p = 0.001; η2 = 0.44). Integrating regular school-based HIIT sessions is a suitable method to improve body composition, cardiorespiratory fitness, and physical activity in students with obesity. Trial Registration: ChiCTR2100048737.

Femoral neck stress fracture and medial tibial stress syndrome following high intensity interval training: A case report and review of literature

BACKGROUND

Femoral and tibial stress injuries are commonly found in long distance running athletes. Stress fractures have rarely been reported in athletes performing high intensity interval training (HIIT) exercise. The objective of this study was to report a case of a patient who presented with medial tibial stress syndrome and femoral neck stress fracture after performing HIIT exercises.

CASE SUMMARY

A 26 year old female presented with bilateral medial tibial pain. She had been performing HIIT exercise for 45 min, five times weekly, for a seven month period. Her tibial pain was gradual in onset, and was now severe and worse on exercise, despite six weeks of rest. Magnetic resonance imaging (MRI) revealed bilateral medial tibial stress syndrome. As she was taking norethisterone for birth control, a dual energy X-ray absorbitometry scan was performed which demonstrated normal bone mineral density of her lumbar spine and femoral neck. She was managed conservatively with analgesia and physiotherapy, but continued to exercise against medical advice. She presented again six months later with severe right hip pain. MRI of her right hip demonstrated an incomplete stress fracture of her subtrochanteric region. Her symptoms resolved with strict rest and physiotherapy.

CONCLUSION

HIIT may cause stress injury of the tibia and femur in young individuals.

Salivary concentrations of IL-8 and IL-1ra after HIIT and MICT in young, healthy adults: A randomized exercise study

The purpose of this study was to determine whether six weeks of high intensity interval training (HIIT) would lead to greater changes in resting concentrations of salivary IL-8 and IL-1ra than moderate intensity continuous training (MICT) in young, healthy adults, and to determine whether changes in IL-8 and IL-1ra after six weeks of either HIIT or MICT were associated with changes in maximal exercise capacity (VO₂max). Participants were randomly assigned to 6 weeks of HIIT (n = 12) or MICT (n = 11), matched for workload. Saliva samples were collected at the beginning (T1) and end (T2) of the intervention, and analyzed for IL-8 and IL-1ra. Participants in both groups had significant improvements in VO₂max; there were no group differences in improvements. A greater reduction in IL-8 was observed in the MICT group when compared to the HIIT group (HIIT median: -9.5; MICT median: -82.3 pg/µg of protein; U = 11.5, p < 0.001). When combining the HIIT and MICT group, there were significant reductions in IL-8 from T1 to T2. There was no correlation between changes in IL-8 (r < 0.00) or IL-1ra (r = -0.013) with changes in VO₂max. In conclusion, 6 weeks of exercise training leads to a reduction in IL-8; MICT may lead to greater reductions when compared to HIIT. Future research examining longer intervention periods is needed to further elucidate the effects of HIIT and MICT on different pro and anti-inflammatory cytokines.

High-Intensity Interval Training for Rowing: Acute Responses in National-Level Adolescent Males

Background: This study investigated the acute effects of two high-intensity interval training (HIIT) programs on physiological responses and internal workload. Methods: Ten national-level adolescent male rowers (age: 15.7 ± 0.2 years; maximal oxygen uptake (VO2max): 60.11 ± 1.91 mL∙kg−1∙min−1) performed two HIIT testing sessions: short (S-HIIT) and long (L-HIIT). In S-HIIT, the rowers performed 25 reps of 30 s at 100% power at VO2max (Pmax) interspersed with 30 s at P@20% Pmax; whereas in L-HIIT, the rowers executed 4 × 4 min at P@90% Pmax interspersed with 3 min of active recovery (P@30% Pmax). Results: The acute physiological responses and internal workload were evaluated. The significance level was set at p < 0.05. Oxygen uptake (VO2) (p < 0.05), time spent per session at ~90% VO2max (p < 0.01), total VO2 consumed (p < 0.01), total distance (p < 0.001), the rating of perceived exertion, blood lactate concentration and heart rate (always p < 0.0001) were significantly higher in L-HIIT than in S-HIIT. However, peak power output was significantly lower in L-HIIT compared to S-HIIT (p < 0.0001). Conclusion: In adolescent rowers, both HIIT tests stimulated aerobic and anaerobic systems. The L-HIIT test was associated with acute cardiorespiratory and metabolic responses, as well as higher perceptions of effort than the S-HIIT test. In adolescent rowers, HIIT emerges as an asset and could be introduced into a traditional in-season, moderate-intensity and endurance-based rowing program once a week.

Exercise and Cardiovascular Disease Risk Factors in Children and Adolescents With Obesity: A Systematic Review With Meta-Analysis of Randomized Controlled Trials

The purpose of this study was to examine the effects of exercise on cardiovascular disease (CVD) risk factors in children and adolescents with obesity. Randomized controlled trials (RCTs) of exercise ≥4 weeks in children and adolescents with obesity were included if one or more CVD risk factors were included as an outcome. Studies were retrieved by searching 7 electronic databases, cross-referencing, and expert review. Data were pooled using the inverse-variance heterogeneity (IVhet) model and strength of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) instrument. Thirty-nine studies representing 1548 participants (847 exercise, 701 control) met the inclusion criteria. Aerobic exercise improved 10 of 12 (83.3%) outcomes (P < .05 for all) while combined aerobic and strength training improved 5 of 8 (62.5%) outcomes (P < .05 for all). The strength of evidence ranged from "very low" to "moderate." It was concluded that aerobic exercise, as well as combined aerobic and strength training, is associated with improvements in multiple CVD risk factors among children and adolescents with obesity. However, the generally low strength of evidence suggests a need for future well-designed and conducted RCTs on the effects of exercise, especially strength training, in children and adolescents with obesity.

Effects of a 5-Year Exercise Intervention on White Matter Microstructural Organization in Older Adults. A Generation 100 Substudy

Aerobic fitness and exercise could preserve white matter (WM) integrity in older adults. This study investigated the effect on WM microstructural organization of 5 years of exercise intervention with either supervised moderate-intensity continuous training (MICT), high-intensity interval training (HIIT), or following the national physical activity guidelines. A total of 105 participants (70-77 years at baseline), participating in the randomized controlled trial Generation 100 Study, volunteered to take part in this longitudinal 3T magnetic resonance imaging (MRI) study. The HIIT group (n = 33) exercised for four intervals of 4 min at 90% of peak heart rate two times a week, the MICT group (n = 24) exercised continuously for 50 min at 70% peak heart rate two times a week, and the control group (n = 48) followed the national guidelines of ≥30 min of physical activity almost every day. At baseline and at 1-, 3-, and 5-year follow-ups, diffusion tensor imaging (DTI) scans were performed, cardiorespiratory fitness (CRF) was measured as peak oxygen uptake (VO2peak) with ergospirometry, and information on exercise habits was collected. There was no group*time or group effect on any of the DTI indices at any time point during the intervention. Across all groups, CRF was positively associated with fractional anisotropy (FA) and axial diffusivity (AxD) at the follow-ups, and the effect became smaller with time. Exercise intensity was associated with mean diffusivity (MD)/FA, with the greatest effect at 1-year and no effect at 5-year follow-up. There was an association between exercise duration and FA and radial diffusivity (RD) only after 1 year. Despite the lack of group*time interaction or group effect, both higher CRF and exercise intensity was associated with better WM microstructural organization throughout the intervention, but the effect became attenuated over time. Different aspects of exercising affected the WM metrics and WM tracts differently with the greatest and most overlapping effects in the corpus callosum. The current study indicates not only that high CRF and exercise intensity are associated with WM microstructural organization in aging but also that exercise's positive effects on WM may decline with increasing age.

Strength and VO2max Changes by Exercise Training According to Maturation State in Children

The health benefits of physical activity (PA) are widely recognized; however, biological maturation contributions are a subject that has been little studied, which is why the aim of this study was to analyze the effect of a six-week training program at moderate-intensity on the muscular strength and aerobic capacity in children between nine and 13 years (13 ± 1.0 years) according to their maturation state. Twenty-six schoolchildren (15 girls) participated in a six-week physical exercise program based on aerobic/anaerobic capacity and coordination skills. Maximal oxygen uptake (VO2max), trunk-lift, push-ups, curl-ups, and handgrip strength (both hands) were measured as response variables. Body mass index (BMI), skeletal maturity indicator (SMI), peak height velocity (PHV), age on peak height velocity (APHV) and sex were considered as covariates. The results of VO2max, push-ups, curl-ups, and handgrip strength were higher after the exercise program in the whole group (p < 0.05). The VO2max showed a greater increase in the normal-weight than in the overweight-obesity children (p = 0.001). Higher results in dominant handgrip strength were observed in girls (p = 0.003). The PHV before intervention presented a positive correlation with the dominant handgrip strength in all kids (r = 0.70, p = 0.001). As a conclusion, the six-week training program improved the physical fitness of children independent of the maturation state. Somatic maturation increases the physical abilities in schoolchildren.

School-based high-intensity interval training programs in children and adolescents: A systematic review and meta-analysis

PURPOSE

1) To investigate the effectiveness of school-based high-intensity interval training (HIIT) interventions in promoting health outcomes of children and adolescents compared with either a control group or other exercise modality; and 2) to explore the intervention characteristics and process outcomes of published school-based HIIT interventions.

METHODS

We searched Medline, Embase, CINAHL, SPORTDiscus, and Web of Science from inception until 31 March 2021. Studies were eligible if 1) participants aged 5-17 years old; 2) a HIIT intervention within a school setting ≥ 2 weeks duration; 3) a control or comparative exercise group; 4) health-related, cognitive, physical activity, nutrition, or program evaluation outcomes; and 5) original research published in English. We conducted meta-analyses between HIIT and control groups for all outcomes with ≥ 4 studies and meta-regressions for all outcomes with ≥ 10 studies. We narratively synthesised results between HIIT and comparative exercise groups.

RESULTS

Fifty-four papers met eligibility criteria, encompassing 42 unique studies (35 randomised controlled trials; 36 with a high risk of bias). Meta-analyses indicated significant improvements in waist circumference (mean difference (MD) = -2.5cm), body fat percentage (MD = -1.7%), body mass index (standardised mean difference (SMD) = -1.0), cardiorespiratory fitness (SMD = +1.0), resting heart rate (MD = -5bpm), homeostatic model assessment-insulin resistance (MD = -0.7), and low-density lipoprotein cholesterol (SMD = -0.9) for HIIT compared to the control group. Our narrative synthesis indicated mixed findings between HIIT and other comparative exercise groups.

CONCLUSION

School-based HIIT is effective for improving several health outcomes. Future research should address the paucity of information on physical activity and nutrition outcomes and focus on the integration and long-term effectiveness of HIIT interventions within school settings.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42018117567.

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.

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.

Impact of high-intensity interval training on cardio-metabolic health outcomes and mitochondrial function in older adults: a review

Exercise being a potent stimulator of mitochondrial biogenesis, there is a need to investigate the effects of high-intensity interval training (HIIT) among older adults. This review explores and summarizes the impact of HIIT on mitochondria and various cardio-metabolic health outcomes among older adults, healthy and with comorbid conditions. Electronic databases were scrutinized for literature using permutations of keywords related to (i) Elderly population (ii) HIIT (iii) Mitochondria, cell organelles, and (iv) cardio-metabolic health outcomes. Twenty-one studies that met the inclusion criteria are included in this review. HIIT is an innovative therapeutic modality in preserving mitochondrial quality with age and serves to be a viable, safe, and beneficial exercise alternative in both ill and healthy older adults.

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

Effects of Movement Behaviors on Overall Health and Appetite Control: Current Evidence and Perspectives in Children and Adolescents

PURPOSE OF REVIEW

To present the definitions and recommendations for movement behaviors in children and adolescents, including physical activity (PA), sedentary behaviors (SB), and sleep, and to provide an overview regarding their impact on health and obesity outcomes from childhood to adulthood, as well as interactions with appetite control.

RECENT FINDINGS

PA represents a variable proportion of daily energy expenditure and one can be active with high SB or vice versa. Studies have described movements across the whole day on a continuum from sleep to SB to varying intensities of PA. More PA, less SB (e.g., less screen time) and longer sleep are positively associated with indicators of physical health (e.g., lower BMI, adiposity, cardiometabolic risk) and cognitive development (e.g., motor skills, academic achievement). However, less than 10% of children currently meet recommendations for all three movement behaviors. Movement behaviors, adiposity, and related cardiometabolic diseases in childhood track into adolescence and adulthood. Furthermore, low PA/high SB profiles are associated with increased energy intake. Recent studies investigating energy balance regulation showed that desirable movement behavior profiles are associated with better appetite control and improved eating habits. Early identification of behavioral phenotypes and a comprehensive approach addressing all key behaviors that directly affect energy balance will allow for individual strategies to prevent or treat obesity and its comorbidities. Investigating exercise as a potential "corrector" of impaired appetite control offers a promising weight management approach.

Sex Moderated Mediation of the Musculoskeletal Fitness in Relationship between High-Intensive Interval Training Performing during Physical Education Classes and Cardiorespiratory Fitness in Healthy Boys and Girls

High-intensive interval training (HIIT) is indicated as a means of improving cardiorespiratory fitness (CRF) and musculoskeletal fitness (MSF). The relationship between CRF and MSF was examined too. Little is known about gaining CRF from HIIT independence of MSF in adolescents. Therefore, this study is aimed at investigating whether MSF mediated the relationship between HIIT and CRF and whether sex moderate this relation. The study sample included 122 individuals (45 boys, 77 girls) 16.12 ± 0.38 years of secondary school age. Participants were assigned to the HIIT intervention or control groups. The intervention lasted 14 minutes during one physical education lesson per week for ten weeks. Outcome and potential mediator were residual changes calculated from pre- and postintervention results of MSF components: handgrip (HG), sit-ups (ABS), sit-and-reach (FL), vertical jump (VJ), and Harvard step-test representing cardiorespiratory fitness (CRF). MSF index (MSFI) was calculated as a construct, agglomerating all MSF, and tested its usefulness. HIIT significantly impacted CRF in boys and girls (B = 2.32, p = 0.032; B = 2.28, p = 0.005, respectively). The impact of the HIIT program on the ABS and FL was observed only in girls. The moderation effect of sex was confirmed. Significant effect of HIIT on CRF decreased (B_direct < B_total) and was no significant after including FL (B = 1.46, p = 0.62)—complete mediation, but no ABS (B = 2.97, p = 0.001)—partial mediation. CRF was mediated by changes in ABS (B = 2.28, p < 0.001) and FL (4.18, p < 0.001). MSFI was not mediating; its usefulness was limited. HIIT is an effective tool in the development of CRF in both sexes. MSF played a limited role in the relationship between HIIT and CRF. It suggested different mechanisms in both sexes: girls who performed better to the HIIT had better values of FL and ABS, but not boys. HIIT intervention involved modifications in ABS or FL, which also influenced the increase of CRF.

Effects of different exercise programs on cardiorespiratory fitness and body composition in college students

Objective

The cardiorespiratory fitness (CRF) of college students is showing a downward trend, this study aimed to explore the effects of three exercise programs on CRF and body composition indicators in college students.

Methods

A total of 50 non-smoking, healthy and physically inactive students were recruited from campus in Beijing, China, and randomly assigned to 4 groups: low-intensity continuous training with blood flow restriction (LICT-BFR, n = 13), moderate-intensity continuous training (MICT, n = 13), high-intensity interval training (HIIT, n = 12), and no exercise control (n = 12), the intervention continued for 8 weeks. Body composition and aerobic capacity were measured before and after the intervention.

Results

Exercise groups reached significant improvements in maximal oxygen uptake (VO₂max, p < 0.01) and a decrease in body fat percentage (p < 0.05) comparing to the control group. The fat mass and visceral fat area reduced significantly (p < 0.05) with a muscle mass growth (p < 0.05) in the LICT-BFR and MICT groups comparing to the control group. Changes of fat and muscle mass were trivial in the HIIT group (p = 0.842, p = 0.247).

Conclusion

All three exercise programs can improve the CRF of college students, with LICT-BFR has the most profound effects, and MICT is more beneficial for body composition improvement than other programs. From an overall perspective, LICT-BFR should be the ideal choice, however, due to limited equipment, college students can choose MICT or HIIT according to their situations.

Effects of High-Intensity Interval Training on Pulmonary Function and Exercise Capacity in Individuals with Chronic Obstructive Pulmonary Disease: A Meta-Analysis and Systematic Review

INTRODUCTION

This study aimed to examine the effectiveness of high-intensity interval training (HIIT) on pulmonary function and exercise capacity in individuals with chronic obstructive pulmonary disease (COPD).

METHODS

Ten databases (PubMed, the Cochrane Library, Web of Science, EMBASE, MEDLINE, CINAHL, CNKI, Wanfang, Weipu, and CBM) were searched for relevant articles published from inception to 30 June 2020. Studies were included if they were randomized controlled trials (RCTs) comparing a HIIT group with usual care or other training groups. Quality was assessed using the Physiotherapy Evidence Database (PEDro) scale, and the overall quality of evidence was assessed using the GRADE approach. The primary outcomes were peak VO2 and FEV1% predicted, and the secondary outcomes were FEV1/FVC, peak VE, peak WR, 6MWD, dyspnea, health-related quality of life, and adverse event.

RESULTS

Twelve articles (689 patients) were included. HIIT was shown to have a positive effect on exercise capacity (peak WR, 6MWD), pulmonary function (FEV1% pred, peak VE), dyspnea, and quality of life. However, sensitivity analyses for dyspnea were unstable, and the result changed from positive to negative after removing one study (SMD = - 0.13, 95% CI [- 0.44, 0.17], P = 0.40).

CONCLUSIONS

HIIT could improve pulmonary function, exercise capacity, and quality of life but may not decrease dyspnea in patients with COPD. It can be recommended as a safe and effective exercise modality in rehabilitation programs. Given that the overall results were based on a limited number of studies with significant heterogeneity and some of the results were based on low GRADE rating evidence, more high-quality, larger sample size, multicenter, and long-term follow-up RCTs are needed to confirm the clinical efficacy of HIIT in patients with COPD.

PROSPERO REGISTRATION

CRD42020165897.

Effect of Cycle-Based High-Intensity Interval Training and Moderate to Moderate-Intensity Continuous Training in Adolescent Soccer Players

Cardiorespiratory fitness, anaerobic power, and lower extremity strength are essential for soccer players at all levels. An effective program should be developed to improve physical strength for adolescent soccer players who need to combine academic and technical training. This study analyzed the impact of short-term high intensity interval training (HIIT) training and traditional moderate intensity continuous training (MICT) on adolescent soccer players. Participants included 56 adolescent soccer players who were divided into HIIT and MICT groups. The training program was conducted 3 times a week for 4 weeks using cycle ergometer. Each session included the same resistance training program, and the characteristics of HIIT and MICT were applied to improve cardiorespiratory fitness and anaerobic power. Body composition analysis, graded exercise test for peak oxygen uptake (VO₂ peak), Wingate anaerobic power test, and isokinetic knee strength test were performed. VO₂ peak was improved in HIIT and MICT, but anaerobic threshold and heart rate recovery significantly improved in the HIIT group. Wingate anaerobic peak power had increased significantly in sets 1, 2, and 3 in the HIIT group, but showed significant improvement only in set 1 in the MICT group. The isokinetic strength improved significantly in the HIIT group at 60°/s and in the MICT group at 240°/s. There was no significant change in body composition in either group. In conclusion, short-term HIIT administered to adolescent soccer players effectively improved cardiorespiratory fitness in HIIT and MICT groups. While HIIT increased anaerobic threshold and power, MICT effectively improved muscle endurance. Short-term intensive training can be considered a time-efficient training strategy.

The Effects of Different Exercise Modalities in the Treatment of Cardiometabolic Risk Factors in Obese Adolescents with Sedentary Behavior-A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PURPOSE

Obesity has become increasingly prevalent in adolescents due to unhealthy diet habits, sedentary behavior and a lack of physical activities. This study aims to assess the effects of different exercise modalities in the treatment of cardiometabolic risk factors (CRF) in obese adolescents with sedentary behavior.

METHODS

A systematic search was conducted using databases (PubMed, Embase, Cochrane library, Web of Science, CNKI and VIP database) from the earliest available date to August 2021. Nineteen randomized controlled trials (RCTs) with 704 participants were included. The included studies were evaluated for methodological quality by the Cochrane bias risk assessment tool, and a statistical analysis was performed by the Review Manage 5.3 and Stata 15.1 software.

RESULTS

The results of the meta-analysis showed that exercise could significantly improve obese adolescents' body mass index (BMI) (MD = -1.99, 95% CI: -2.81 to -1.17, p < 0.00001), low density liptein cholesterol (LDL-C) (SMD = -0.98, 95% CI: -1.58 to -0.37, p = 0.002), triglyceride (TG) (SMD = -0.93, 95% CI: -1.72 to -0.14, p = 0.02), total cholesterol (TC) (SMD = -1.00, 95% CI: -1.73 to -0.26, p = 0.008), peak oxygen uptake (VO₂peak) (MD = 3.27, 95% CI: 1.52 to 5.02, p = 0.0003) and homeostatic model assessment insulin resistance (HOMA-IR) (SMD = -2.07, 95% CI: -3.3 to -0.84, p = 0.001). However, there was no statistically significant difference in high-density liptein cholesterol (HDL-C) (SMD = 0.40, 95% CI: -0.28 to 1.08, p = 0.25).

CONCLUSION

Exercise can effectively improve cardiometabolic risk factors in obese adolescents with sedentary behavior. For obese adolescents who want to lose weight and improve cardiorespiratory fitness, combined aerobic and resistance training and high-intensity interval training are optimal choices. For obese adolescents with high blood lipids, aerobic training can be regarded as a primary exercise modality to reduce the high risk of cardiovascular diseases; For obese adolescents with insulin resistance, combined aerobic and resistance training can be considered to reduce the high risk of diabetes. It is hoped that more high-quality studies will further expand the meta-analysis results and demonstrate the optimal exercise frequency and treatment intensity of cardiometabolic risk factors in obese adolescents with sedentary behavior in the future.

Effect of High-Intensity Interval Training on Physical Health in Coronary Artery Disease Patients: A Meta-Analysis of Randomized Controlled Trials

The effects of exercise-based cardiac rehabilitation (CR) on physical health in coronary artery disease (CAD) patients has long been established, while the optimal exercise mode remains to be determined. This meta-analysis compared the efficacy of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) in CAD patients. Databases were searched up to December 2020. Twenty-five studies with 1272 participants were analyzed. The results showed that both HIIT and MICT induced significant VO_2peak improvement with a 4.52 mL/kg/min (p < 0.01) and 2.36 mL/kg/min (p < 0.01), respectively. Additionally, a larger improvement of VO_2peak (1.92 mL/kg/min, p < 0.01) was observed in HIIT over MICT. HIIT with medium and long intervals, higher work/rest ratio induced larger VO_2peak improvement than the compared subgroup. Interestingly, non-isocaloric exercise protocols induced larger VO_2peak improvement compared with isocaloric protocols. In addition, both HIIT and MICT significantly increased anaerobic threshold and peak power with HIIT superior to MICT. No significant different changes were observed in blood pressure after HIIT or MICT intervention, however when HIIT was compared with MICT, MICT seems superior to HIIT in reducing systolic blood pressure (−3.61 mmHg, p < 0.01) and diastolic blood pressure (−2.37 mmHg, p < 0.01). Although, HIIT and MICT induced significant improvement of most other parameters, like HR_rest, HR_peak, left ventricular ejection fraction (LVEF), quality of life (QoL), no significant differences were noted between groups. This meta-analysis suggested that HIIT is superior to MICT in increasing VO_2peak, anaerobic threshold, peak power in CAD patients. Additionally, the efficacy of HIIT over MICT in improving VO_2peaks was influenced by HIIT intervals, work/rest ratio and total caloric consumption. Both HIIT and MICT did not significantly influence resting BP, however, MICT seemed to be more effective in reducing BP than HIIT. HIIT and MICT equally significantly influenced HR_rest, HR_peak, HRR1min, OUES, LVEF%, QoL.

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.

Left ventricular mechanical, cardiac autonomic and metabolic responses to a single session of high intensity interval training

PURPOSE

High-intensity interval training (HIIT) produces significant health benefits. However, the acute physiological responses to HIIT are poorly understood. Therefore, we aimed to measure the acute cardiac autonomic, haemodynamic, metabolic and left ventricular mechanical responses to a single HIIT session.

METHODS

Fifty young, healthy participants completed a single HIIT session, comprising of three 30-s maximal exercise intervals on a cycle ergometer, interspersed with 2-min active recovery. Cardiac autonomics, haemodynamics and metabolic variables were measured pre-, during and post-HIIT. Conventional and speckle tracking echocardiography was used to record standard and tissue Doppler measures of left ventricular (LV) structure, function and mechanics pre- and post-HIIT.

RESULTS

Following a single HIIT session, there was significant post-exercise systolic hypotension (126 ± 13 to 111 ± 10 mmHg, p < 0.05), parallel to a significant reduction in total peripheral resistance (1640 ± 365 to 639 ± 177 dyne⋅s⋅cm⁵, p < 0.001) and significant increases in baroreceptor reflex sensitivity and baroreceptor effectiveness index (9.2 ± 11 to 24.8 ± 16.7 ms⋅mmHg^-1 and 41.8 ± 28 to 68.8 ± 16.2, respectively) during recovery compared to baseline. There was also a significant increase in the low- to high-frequency heart rate variability ratio in recovery (0.7 ± 0.48 to 1.7 ± 1, p < 0.001) and significant improvements in left ventricular global longitudinal strain (- 18.3 ± 1.2% to - 29.2 ± 2.3%, p < 0.001), and myocardial twist mechanics (1.27 ± 0.72 to 1.98 ± 0.72°·cm^-1, p = 0.028) post-HIIT compared to baseline.

CONCLUSION

A single HIIT session is associated with acute improvements in autonomic modulation, haemodynamic cardiovascular control and left ventricular function, structure and mechanics. The acute responses to HIIT provide crucial mechanistic information, which may have significant acute and chronic clinical implications.

Exercise Intervention for Academic Achievement Among Children: A Randomized Controlled Trial

OBJECTIVES

Physical inactivity is an important health concern worldwide. In this study, we examined the effects of an exercise intervention on children's academic achievement, cognitive function, physical fitness, and other health-related outcomes.

METHODS

We conducted a population-based cluster randomized controlled trial among 2301 fourth-grade students from 10 of 11 public primary schools in 1 district of Ulaanbaatar between February and December 2018. Schools were allocated to an intervention or control group with 5 schools each by using urban and mixed residential area stratified block randomization. The intervention group received a 3-minute high-intensity interval exercise program that included jumps, squats, and various steps implemented twice weekly over 10 weeks for 10 to 25 minutes per session. The control group received the usual physical education class. The primary outcome was academic achievement assessed by scores on the national examination. A linear mixed-effects model was applied. The difference between preintervention and post intervention was compared by least-squares means, estimated on the basis of the interaction of group, measurement time point, and school location. Only 1 statistician, responsible for the analysis, was blinded.

RESULTS

Of 2301 students, 2101 (1069 intervention; 1032 control) were included in the analysis. Intervention group members in an urban area showed an 8.36-point improvement (95% confidence interval: 6.06 to 10.66) in academic scores when compared with the control group, whereas those in a mixed residential area showed a 9.55-point improvement (95% confidence interval: 6.58 to 12.51). No intervention-associated injuries were observed.

CONCLUSIONS

The exercise program significantly improved children's academic achievement.

High-Intensity Interval Training and Cardiometabolic Risk Factors in Children: A Meta-analysis

CONTEXT

High-intensity interval training (HIIT) has been widely used to prevent and treat cardiovascular risk factors in adolescents and adults; nevertheless, the available evidence in children is scarce.

OBJECTIVE

To synthesize evidence regarding the effectiveness of HIIT interventions on improving cardiovascular risk factors and cardiorespiratory fitness (CRF) in children from 5 to 12 years old.

DATA SOURCES

We searched 5 databases, Medline, Embase, SPORTDiscus, the Cochrane Library, and Web of Science.

STUDY SELECTION

Randomized controlled trials (RCTs) evaluating the effectiveness of HIIT interventions on cardiometabolic risk factors and CRF in children were included.

DATA EXTRACTION

Meta-analyses were conducted to determine the effect of HIIT on body composition, cardiometabolic and CRF variables in comparison with nontraining control groups.

RESULTS

A total of 11 RCTs and 512 participants were included. The results of the meta-analysis revealed a significant improvement in peak oxygen uptake (standardized mean difference [SMD] = 0.70, 95% confidence interval [CI] = 0.28 to 1.12; P = 0.001], in total cholesterol [SMD = -1.09, 95% CI = -1.88 to -0.30; P = 0.007], in low-density lipoprotein cholesterol [SMD = -1.28, 95% CI = -2.34 to -0.23; P = 0.017] and triglycerides [SMD = -0.71, 95% CI = -1.15 to -0.28; P = 0.001) levels.

LIMITATIONS

Because of the small number of available RCTs, it was not possible to conduct a subgroup analysis or a linear meta-regression analysis.

CONCLUSIONS

HIIT is a feasible and time-efficient approach for improving CRF, total cholesterol, low-density lipoprotein cholesterol, and triglycerides levels in children.

Effekte von hochintensivem Intervalltraining (HIIT) auf Body-Mass-Index (BMI) und Körperfettanteil von übergewichtigen und adipösen Kindern – eine systematische Übersichtsarbeit

Hintergrund Mehr als 340 Millionen Kinder gelten weltweit als übergewichtig oder adipös, ihre Anzahl nahm in den letzten Jahren – auch durch die Coronapandemie – erheblich zu. Eine alternative Behandlung zur Reduzierung des Übergewichts, die in den Empfehlungen bisher keine große Beachtung findet, stellt das sogenannte hochintensive Intervalltraining (HIIT) dar.

Ziel Darstellung der Wirksamkeit von hochintensivem Intervalltraining auf den BMI und Körperfettanteil übergewichtiger und adipöser Kinder im Alter von 6–13 Jahren.

Methode Die Erstellung der systematischen Übersichtsarbeit orientierte sich an den PRISMA-Guidelines. Für die Literaturrecherche wurden die Datenbanken MEDLINE, Cochrane Library, CINAHL, Embase, Sports Medicine & Education Index und Web of Science nach Studien mit hochintensivem Intervalltraining für übergewichtige und adipöse Kinder durchsucht. Die Bewertung der methodischen Studienqualität erfolgte mittels PEDro-Skala, MINORS und Risk of Bias. Die Berichtsqualität wurde anhand von CONSORT und TREND bewertet.

Ergebnisse Es wurden 6 randomisierte kontrollierte Studien und 2 kontrollierte klinische Studien mit 479 HIIT-Teilnehmenden betrachtet. Diese zeigten, dass hochintensives Intervalltraining positive Auswirkungen auf den BMI und Körperfettanteil übergewichtiger und adipöser Kinder hat.

Schlussfolgerung Hochintensives Intervalltraining ist eine kinderfreundliche und zugleich effektive Alternative zur Behandlung von übergewichtigen und adipösen Kindern. Weitere klinische Studien sind erforderlich, um die Ergebnisse zu bekräftigen.

Jumping into a Healthier Future: Trampolining for Increasing Physical Activity in Children

OBJECTIVES

Physical activity in children and adolescents has positive effects on cardiopulmonary function in this age group as well as later in life. As poor cardiopulmonary function is associated with higher mortality and morbidity, increasing physical activity especially in children needs to become a priority. Trampoline jumping is widely appreciated in children. The objective was to investigate its use as a possible training modality.

METHODS

Fifteen healthy children (10 boys and 5 girls) with a mean age of 8.8 years undertook one outdoor incremental running test using a mobile cardiopulmonary exercise testing unit. After a rest period of at least 2 weeks, a trampoline test using the mobile unit was realized by all participants consisting of a 5-min interval of moderate-intensity jumping and two high-intensity intervals with vigorous jumping for 2 min, interspersed with 1-min rests.

RESULTS

During the interval of moderate intensity, the children achieved [Formula: see text]-values slightly higher than the first ventilatory threshold (VT1) and during the high-intensity interval comparable to the second ventilatory threshold (VT2) of the outdoor incremental running test. They were able to maintain these values for the duration of the respective intervals. The maximum values recorded during the trampoline test were significantly higher than during the outdoor incremental running test.

CONCLUSION

Trampoline jumping is an adequate tool for implementing high-intensity interval training as well as moderate-intensity continuous training in children. As it is a readily available training device and is greatly enjoyed in this age group, it could be implemented in exercise interventions.