# The Prevalence of Responders and Non-Responders for Body Composition, Resting Blood Pressure, Musculoskeletal, and Cardiorespiratory Fitness after Ten Weeks of School-Based High-Intensity Interval Training in Adolescents PMID: 37445239 Journal: Journal of clinical medicine Published: 2023-06-21 Authors: Domaradzki J, Koźlenia D, Popowczak M ## Question What proportion of adolescents respond or do not respond in body composition, blood pressure, musculoskeletal fitness, and cardiorespiratory fitness after a 10-week school-based HIIT program, and are responses related to sex, BMI, or maturation? ## Summary A 10-week school PE Tabata program found that adolescents varied substantially in who improved after once-weekly HIIT. More students were classified as responders than non-responders for body fat percentage, skeletal muscle mass, blood pressure, cardiorespiratory fitness, and abdominal strength, but many did not improve in hand strength or vertical jump. ## Population - Healthy mid-adolescent boys and girls in secondary-school PE. - Sample size: 73 - Age: Boys 16.20 +/- 0.31 years; girls 16.12 +/- 0.39 years. - Sex: 31 boys and 42 girls in the experimental-group analysis. - Fitness level: School PE population, not selected athletes. - Health status: Apparently healthy adolescents. ## Methodology - Responder/non-responder analysis of experimental participants from a school-based HIIT project. - 10 weeks. - Secondary-school physical education classes in Wroclaw, Poland. - Randomized study design. ## Protocol - School-based Tabata PE HIIT. - Modality: Bodyweight Tabata-style intervals embedded in PE lessons. - Work intervals: Each Tabata block used 8 cycles of 20 seconds of maximal-intensity exercise followed by 10 seconds of active rest. - Recovery: Each Tabata block used 8 cycles of 20 seconds of maximal-intensity exercise followed by 10 seconds of active rest. - Sets or repetitions: Each standard 45-minute PE lesson included a 10-minute warm-up followed by a 14-minute Tabata aerobic protocol made up of three 4-minute Tabata blocks. - Intensity: Target high intensity was 75-80% HRmax, with HRmax estimated as 208 - 0.7 x age. Heart rate was monitored in an initial lesson, with mean HR about 155.8 +/- 18.2 bpm. - Session duration: Each standard 45-minute PE lesson included a 10-minute warm-up followed by a 14-minute Tabata aerobic protocol made up of three 4-minute Tabata blocks. - Frequency: 1 session per week. - Program length: 10 weeks. - Progression: The same PE Tabata structure was repeated across the intervention. - The article's responder analysis did not use a concurrent comparator in the main reported responder-prevalence results, although the larger project included a control group. - Modality: Not applicable to the main responder analysis. ## Outcomes ### Body composition, fitness, and blood pressure Status: mixed The intervention was associated with significant effects for body fat mass, fitness index, systolic blood pressure, and sex-dependent abdominal strength and flexibility outcomes. ### Responder prevalence for body composition and fitness Status: improved More responders than non-responders were observed for body fat percentage, skeletal muscle mass, systolic blood pressure, diastolic blood pressure, fitness index, and abdominal strength. ### Hand strength and vertical jump response Status: mixed More non-responders than responders were observed for hand strength and vertical jump. ### Sex-related response patterns Status: mixed Sex was associated with abdominal-strength response and was close to significance for skeletal-muscle-mass response; boys were more likely to be skeletal-muscle-mass responders and girls more likely to be abdominal-strength responders. ### Maturation-related response patterns Status: mixed Maturation status was related to skeletal-muscle-mass and systolic-blood-pressure response, while BMI was not clearly associated with response status. ## Practical Insights - Even a low-frequency, once-weekly Tabata block in PE can produce measurable improvements in some adolescents, but response is heterogeneous. - Responder analysis may be useful for HIIT personalization because average effects can hide substantial non-response in strength, power, or motor outcomes. - Sex and maturation may matter when interpreting adolescent HIIT outcomes, particularly for body composition and abdominal strength. - A 14-minute bodyweight Tabata block is a practical school-friendly format. ## Limitations - The paper's main responder analysis included only experimental participants, so causal interpretation is weaker than a full randomized comparison. - HIIT was performed only once weekly for 10 weeks. - The sample excluded prepubertal and peripubertal adolescents. - Nutrition was not controlled. - Body composition was not measured with DXA. - Cardiorespiratory fitness was estimated by the Harvard Step Test rather than direct VO2max testing. ## Safety And Adherence - No adverse-event reporting was identified in the extracted article text. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/37445239/) (pubmed) - [DOI](https://doi.org/10.3390/jcm12134204) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10342639/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.