Enhancing adolescent health: the role of strength and endurance school-based HIIT interventions in physical fitness and cognitive development
Question
Do 8 weeks of strength- and endurance-focused HIIT integrated into PE classes improve physical fitness and cognitive attention outcomes in adolescents?
Summary
This quasi-experimental school study tested 8 weeks of PE-class HIIT in Spanish adolescents. The experimental group completed one strength-focused and one endurance-focused HIIT session per week, using 30-second work and 30-second rest blocks with heart-rate monitoring. Fitness and attention measures improved, but weight and waist circumference increased, and the study was not randomized.
Methodology
- Healthy secondary education students aged 13-17 years in a Spanish school.
- 84 participants.
- Mixed bodyweight, functional, martial-arts-inspired, strength, and endurance drills.
- Work intervals: 30 seconds high intensity.
- Recovery: 30 seconds rest.
- Intensity: High intensity with mean HR 169.53 +/- 2.93 bpm; HRmax estimated as 220 - age.
- 35-40 minutes of engagement motor time within a 55-minute PE class.
- 2 sessions/week.
- 8 weeks.
- Quasi-experimental pre-post study with experimental and control groups assigned by class.
- Estimated VO2max, Strength and agility fitness, Anthropometry, and Attention and concentration were tracked.
Outcomes
Physical fitness
Experimental group improved horizontal jump, handgrip, 4 x 10 m time, and estimated VO2max; control did not improve most fitness outcomes.
EG HJ +4.68% p=0.001; handgrip +3.24% p=0.03; 4x10 m -8.35% p=0.001; VO2max +5.06% p=0.001.
Attention
Experimental group improved concentration and reduced omission and commission errors.
Concentration +27.44% p=0.001; omissions -53.35% p=0.001; commissions -87.67% p=0.001.
Anthropometry
Experimental group weight and waist circumference increased; BMI increase was not significant.
Weight +2.82% p=0.001; WC +7.99% p=0.001; BMI +6.80% p=0.23.
Heart rate intensity
Experimental sessions produced higher HR than control PE.
EG 169.53 +/- 2.93 bpm vs CG 144.54 +/- 30.08 bpm, p<0.001.
Insights
- School HIIT can be organized as separate strength and endurance sessions within existing PE.
- Heart-rate monitoring is useful for managing adolescent school HIIT intensity.
- Fitness and attention gains should be separated from body-composition claims.
Limitations
- Quasi-experimental class assignment.
- School context and student motivation, nutrition, sleep, and extracurricular activity were uncontrolled.
- Intervention length limited by school calendar.
- No long-term follow-up.
- VO2max was estimated rather than directly measured.
Safety
- No adverse events were reported.
- Students with relevant medical conditions, injuries, or medications were excluded.
- HR monitoring was used so students could moderate intensity.