Was it a HIIT? A process evaluation of a school-based high-intensity interval training intervention

BACKGROUND

Despite a growing body of research investigating high-intensity interval training (HIIT) in schools, there are limited process evaluations investigating their implementation. This is concerning because process evaluations are important for appropriately interpreting outcome findings and augmenting intervention design. This manuscript presents a process evaluation of Making a HIIT, a school-based HIIT intervention.

METHODS

The Making a HIIT intervention spanned 8 weeks and was completed at three schools in Greater Brisbane, Australia. Ten classes (intervention group) completed 10-min teacher-led HIIT workouts at the beginning of health and physical education (HPE) lessons, and five classes (control group) continued with regular HPE lessons. The mixed methods evaluation was guided by the Framework for Effective Implementation by Durlak and DuPre.

RESULTS

Program reach: Ten schools were contacted to successfully recruit three schools, from which 79% of eligible students (n = 308, x ¯ age: 13.0 ± 0.6 years, 148 girls) provided consent. Dosage: The average number of HIIT workouts provided was 10 ± 3 and the average number attended by students was 6 ± 2. Fidelity: During HIIT workouts, the percentage of time students spent at ≥ 80% of maximum heart rate (HRmax) was 55% (interquartile range (IQR): 29%-76%). Monitoring of the control group: During lessons, the intervention and control groups spent 32% (IQR: 12%-54%) and 28% (IQR: 13%-46%) of their HPE lesson at ≥ 80% of HRmax, respectively. Responsiveness: On average, students rated their enjoyment of HIIT workouts as 3.3 ± 1.1 (neutral) on a 5-point scale. Quality: Teachers found the HIIT workouts simple to implement but provided insights into the time implications of integrating them into their lessons; elements that helped facilitate their implementation; and their use within the classroom. Differentiation: Making a HIIT involved students and teachers in the co-design of HIIT workouts. Adaption: Workouts were modified due to location and weather, the complexity of exercises, and time constraints.

CONCLUSION

The comprehensive evaluation of Making a HIIT provides important insights into the implementation of school-based HIIT, including encouragings findings for student enjoyment and fidelity and recommendations for improving dosage that should be considered when developing future interventions.

TRIAL REGISTRATION

ACTRN, ACTRN12622000534785 , Registered 5 April 2022 - Retrospectively registered.

Validation and Calibration for Embedding Rating of Perceived Exertion Into High-Intensity Interval Exercise in Adolescents: A Lab-Based Study

PURPOSE

Rating of perceived exertion (RPE) is a convenient and cost-effective tool that can be used to monitor high-intensity interval exercise (HIIE). However, no methodological study has demonstrated the validity of RPE in this context. Therefore, the aim of this study was to validate and calibrate RPE for monitoring HIIE in adolescents.

METHODS

RPE, heart rate (HR), and oxygen uptake (V˙O2) data were retrospectively extracted from 3 lab-based crossover studies, with a pooled sample size of 45 adolescents, performing either cycling-based or running-based HIIE sessions. Within-participant correlations were calculated for RPE-HR and RPE-V˙O2, and receiver operator characteristic curve analysis was used to establish RPE cut points.

RESULTS

The results showed that RPE-HR demonstrated acceptable criterion validity (r = .53-.74, P < .01), while RPE-V˙O2 had poor validity (r = .40-.48, P < .01), except for HIIE at 100% peak power (r = .59, P < .01). RPE cut points of 4 and 5 were established in corresponding to HR/V˙O2 based thresholds.

CONCLUSION

RPE has some utility in evaluating intensity during lab-based running or cycling HIIE in adolescents. Future studies should expand the validation and calibration of RPE for prescribing and monitoring HIIE in children and adolescents in field-based contexts.

Making a HIIT: co-design of high-intensity interval training workouts with students & teachers within the curriculum

BACKGROUND

High-intensity interval training (HIIT) interventions are becoming more common in schools. However, limited input has been sought from end-users, which can help design interventions that are more engaging and context appropriate, therefore increasing their potential for successful implementation. One method of engaging end-users is co-design, which involves an active collaboration to design solutions to pre-specified problems. This paper aimed to: (1) describe the methodology and results of the co-design process in Making a HIIT to develop HIIT workouts for a school-based intervention; and (2) evaluate the feasibility and impact of co-designing HIIT workouts with students and teachers within the health and physical education (HPE) curriculum.

METHODS

The development of the HIIT workouts occurred during obligatory HPE lessons with year seven and eight students. The co-design process included: (1) identifying barriers and facilitators to exercise to create evaluation criteria for creating the HIIT workouts; (2) exploring HIIT; (3) defining HIIT parameters (intensity and interval length); (4) creating HIIT workouts using the parameters and evaluation criteria; (5) trialling and modifying the HIIT workouts based on class feedback and intensity data. To evaluate the feasibility and impact of the co-design process, a thematic analysis was completed using teacher interviews, student discussions, and student surveys.

RESULTS

Five classes comprised of 121 students (12-14 years; 49% female) and five teachers were involved in the co-design process across three schools in Queensland, Australia. A total of 33 HIIT workouts were created aimed at satisfying the HIIT parameters and variations of the following evaluation criteria: (1) fun; (2) social; (3) achievable skill level; (4) feeling accomplished; and (5) beneficial for health. From the thematic analysis, three themes (acceptability; implementation; integration) and 12 codes contributed to the overarching understanding of the feasibility of the lessons within the curriculum and a further three themes (perceived changes to lessons; educative outcomes; personal and social capabilities) and three codes contributed towards understanding their impact.

CONCLUSION

Overall, co-designing HIIT workouts was feasible within the HPE curriculum and may have contributed to positive educative outcomes. Using this methodology could improve the implementation of HIIT interventions within HPE while supporting educative benefits.

Making a HIIT: Methods for quantifying intensity in high-intensity interval training in schools and validity of session rating of perceived exertion

Using the data from Making a HIIT, this paper aimed to: 1) investigate the different heart rate (HR) quantification methods reported in school-based high-intensity interval training (HIIT) studies; and 2) assess the criterion validity of session rating of perceived exertion (RPE). During an 8-week HIIT intervention, 213 students (13.1 (0.6) years; 46% female) completed 10-minute HIIT workouts during physical education lessons. In total, 1057 HR and RPE measurements were collected across 68 HIIT workouts. For aim 1, the average and peak HR across all participants and workouts were 79% (8%) and 92% (6%) of HRmax, respectively. The average RPE was 6 (2) points on a 10-point scale. An average of 51% of students in a class had an average HR ≥ 80% for each workout. The between-person variation for peak and average HR were 19% and 30% , respectively. Both average and peak HR decreased by 0.5% each week (p < 0.001). To assess aim 2, a within-participant correlation was calculated for the internal training load produced using HR and RPE data. The correlation was 0.39 (p < 0.001), which suggests utility of using RPE when HR is not a viable option.

Making a HIIT: study protocol for assessing the feasibility and effects of co-designing high-intensity interval training workouts with students and teachers

Background

High-intensity interval training (HIIT) is an effective strategy for improving a variety of health outcomes within the school setting. However, there is limited research on the implementation of school-based HIIT interventions and the integration of HIIT within the Health and Physical Education (HPE) curriculum. The aims of the Making a HIIT study are to: 1) describe the methodology and evaluate the feasibility of co-designing HIIT workouts with students and teachers in HPE; 2) determine the effect of co-designed HIIT workouts on cardiorespiratory and muscular fitness, and executive function; 3) understand the effect of co-design on students’ motivation, enjoyment, and self-efficacy towards the workouts; and 4) evaluate the implementation of the intervention.

Methods

Three schools will participate. Within each school, three different groups will be formed from Year 7 and 8 classes: 1) Co-Designers; 2) HIIT Only; and 3) Control. The study will include two phases. In phase one, Group 1 will co-design HIIT workouts as part of the HPE curriculum using an iterative process with the researcher, teacher, and students as collaborators. This process will be evaluated using student discussions, student surveys, and teacher interviews. In phase two, Groups 1 and 2 will use the co-designed 10-minute HIIT workouts in HPE for 8-weeks. Group 3 (control) will continue their regular HPE lessons. All students will participate in cardiorespiratory fitness, muscular fitness, and executive function assessments before and after the HIIT program or control period. Students will complete questionnaires on their motivation, enjoyment, and self-efficacy of the workouts. Differences between groups will be assessed using linear regressions to account for covariates. Heart rate and rating of perceived exertion will be collected during each HIIT session. The implementation will be evaluated using the Framework for Effective Implementation. Ethical approval was granted by the University of Queensland Human Research Ethics Committee and other relevant bodies.

Discussion

This study will be the first to co-design HIIT workouts with teachers and students within the HPE curriculum. As this study relies on co-design, each HIIT workout will differ, which will add variability between HIIT workouts but increase the ecological validity of the study.

Trial registration

ACTRN, ACTRN12622000534785, Registered 5 April 2022 – Retrospectively registered, https://www.anzctr.org.au/ACTRN12622000534785.aspx

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03440-w.

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.

High hopes: lower risk of death due to mental disorders and self-harm in a century-long US Olympian cohort compared with the general population

OBJECTIVE

To determine the risk of death due to prominent mental disorders, substance abuse, and self-harm among US Olympians compared with the general population.

METHODS

All female (n=2301) and male (n=5823) US Olympians who participated in the summer or winter Games between 1912 and 2012 were followed until 2016. The National Death Index certified their vital statuses and causes of death. We performed a Standard Mortality Ratio (SMR) analysis for all causes studied and applied the years-saved (YS) method to quantify differences in the risk of death for (1) anxiety, depression and self-harm and (2) substance abuse and eating disorders. Additionally, we examined the YS across sports with greater than 100 total deaths and between medalists and non-medalists.

RESULTS

US Olympians had a 32% (SMR=0.68, 95% CI 0.49 to 0.91) lower risk of death compared with the general population, resulting in a longevity advantage of 0.21 YS (95% CI 0.14 to 0.29) for deaths by depression, anxiety and self-harm and 0.12 years (95% CI 0.08 to 0.15) for substance abuse and eating disorders. There were no significant differences between medalists and non-medalists, but findings varied by sports. Most sports (eg, athletics, swimming, rowing) had significantly lower risks of deaths than the general population with the exceptions of fencing and shooting. Shooting showed a trend towards a higher risk through suicide by firearm.

CONCLUSION

Olympians have a lower risk of death, favouring an increased longevity compared with the general population for mental disorders, substance abuse and suicides.

Intimal thickening at coronary bifurcations in pediatric heart transplant recipients

Heart transplant recipients are at increased risk for atherosclerosis and cardiac allograft vasculopathy, both initially presenting as intimal thickening. We aimed to determine the presence, extent, and anatomical characteristics of intimal thickness at coronary bifurcations in children using OCT. We measured the intimal thickness of coronary arteries in pediatric transplant recipients using OCT during routine cardiac catheterization. Intimal thickening was defined as (i) a percent change in contralateral intimal thickness greater than 50% when comparing the thickness at the bifurcation to the baseline thickness, and (ii) greater than 0.1 mm. We evaluated 153 unique coronary bifurcations in 31 children (58% boys, median 12.7 years). Intimal thickening was almost exclusively observed in the left coronary system (22 of 67 bifurcations) and rare in the right coronary system (2 of 86 bifurcations; P < .001). There was a positive association between the relative size of the side branch and contralateral intimal thickening at coronary bifurcations (P = .009). Intimal thickening at coronary bifurcations is already present in the left coronary system in many pediatric transplant recipients. The correlation between intimal thickening and side branch size suggests that low shear stress and oscillating shear stress may have an important role in the development of intimal thickening at coronary bifurcations.

Validity and reliability of the Physical Activity Questionnaire for Children (PAQ-C) and Adolescents (PAQ-A) in individuals with congenital heart disease

OBJECTIVE

To assess the criterion validity, internal consistency, reliability and cut-point for the Physical Activity Questionnaire for Children (PAQ-C) and Adolescents (PAQ-A) in children and adolescents with congenital heart disease-a special population at high cardiovascular risk in whom physical activity has not been extensively evaluated.

METHODS

We included 84 participants (13.6±2.9 yrs, 50% female) with simple (37%), moderate (31%), or severe congenital heart disease (27%), as well as cardiac transplant recipients (6%), from BC Children's Hospital, Canada. They completed the PAQ-C (≤11yrs, n = 28) or-A (≥12yrs, n = 56), and also wore a triaxial accelerometer (GT3X+ or GT9X) over the right hip for 7 days (n = 59 met valid wear time criteria).

RESULTS

Median daily moderate-to-vigorous physical activity was 46.9 minutes per day (IQR 31.6-61.8) and 25% met physical activity guidelines defined as ≥60 minutes of moderate-to-vigorous physical activity per day. Median PAQ-score was 2.6 (IQR 1.9-3.0). PAQ-Scores were significantly related to accelerometry-derived metrics of physical activity (rho = 0.44-0.55, all p<0.01) and sedentary behaviour (rho = -0.53, p<0.001). Internal consistency was high (α = 0.837), as was reliability (stability) of PAQ-Scores over a 4-months period (ICC = 0.73, 95%CI 0.55-0.84; p<0.001). We identified that a PAQ-Score cut-point of 2.87 discriminates between those meeting physical guidelines and those that do not in the combined PAQ-C and-A samples (area under the curve = 0.80 (95%CI 0.67-0.92).

CONCLUSION

Validity and reliability of the PAQ in children and adolescents with CHD was comparable to or stronger than previous studies in healthy children. Therefore, the PAQ may be used to estimate general levels of physical activity in children and adolescents with CHD.

Physical Activity and Sedentary Behavior in Children With Congenital Heart Disease

Background

Children with congenital heart disease (CHD) are thought to have low levels of physical activity (PA), but few studies have used objective measures of PA in this population.

Methods and Results

We recruited patients with mild, moderate, and severe CHD and cardiac transplant recipients, aged 8 to 19 years, from pediatric cardiology clinics throughout British Columbia and Yukon, Canada. Participants were fitted with an ActiGraph accelerometer to be worn over the right hip for 7 days. Daily means were estimated for a variety of accelerometry‐derived metrics, including moderate‐to‐vigorous PA and percentage of sedentary time if they had at least 3 valid days of accelerometry data. Participants also completed a PA questionnaire. We included 90 participants (aged 13.6±2.7 years; 54% male), of which 26 had mild CHD, 26 had moderate CHD, 29 had severe CHD, and 9 were cardiac transplant recipients. Median daily moderate‐to‐vigorous PA was 43 min/day (interquartile range: 28.9–56.9 min/day), and 8% met PA guidelines of 60 minutes of moderate‐to‐vigorous PA at least 6 days a week. There were no significant differences in any accelerometry‐derived metric according to CHD severity. Boys were significantly more active and less sedentary than girls. Activity declined and sedentary behaviors increased with age in both sexes. Sports participation was common, including competitive out‐of‐school clubs (57%). PA restrictions from cardiologists were rare (15%).

Conclusions

We found normal age–sex patterns of PA in children with CHD. There were no differences in PA by CHD severity, suggesting that sociocultural factors are likely important determinants of PA in these children.