The Study
Effects of High-Intensity Interval Training on Steroid Hormones and Psychological Outcomes in Healthy Male Adolescents: A Randomized Controlled Trial
This study showed that when teenage boys did a specific kind of intense exercise for 10 weeks, their fitness and stress levels got better—but it doesn’t prove the exercise caused those changes for everyone. It’s like noticing your friend felt happier after starting soccer, but you can’t say soccer makes everyone happy.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Teens who did short, intense sprints three times a week for 10 weeks got fitter, had better hormone balance, and felt less stressed — but their sadness or anxiety didn’t change.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 574 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1These changes mean teens became physically stronger and their bodies shifted from stress mode to growth mode — but the training didn’t fix deeper mood problems.
- 2VO2max went up by 13%, testosterone up 61.5%, cortisol down 10.7%, stress down 22%.
- 3No change in depression or anxiety.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Sports
Year
2026
Authors
Nejmeddine Ouerghi, Wissal Abassi, Nidhal Jebabli, Mohamed Bessem Hammami, Anissa Bouassida, Katja Weiss, Thomas Rosemann, Moncef Feki, Beat Knechtle
Related Content
Claims (6)
In healthy male adolescents aged 14–16, ten weeks of high-intensity interval training three times per week with 30-second sprints and 30-second recovery periods increases maximal oxygen uptake by 13% and maximal aerobic speed by 15% compared to no exercise.
In healthy male adolescents aged 14–16, performing high-intensity interval training three times per week for ten weeks results in a 61.5% increase in plasma testosterone, a 93% increase in the testosterone-to-cortisol ratio, and a 10.7% decrease in cortisol levels.
After 10 weeks of high-intensity interval training, healthy boys aged 14 to 16 show no change in depressive or anxiety symptoms, even though their stress levels and physical fitness improve.
In healthy male teenagers aged 14 to 16, doing high-intensity interval training three times a week for ten weeks lowers self-reported stress levels by about 22% compared to those who do not exercise, but does not change levels of depression or anxiety.
In healthy teenage boys aged 14 to 16, a 10-week program of high-intensity interval training raises the ratio of testosterone to cortisol, indicating a shift in the body's hormonal balance toward muscle-building processes and away from stress-related breakdown, without changing the total amounts of either hormone.
Higher intensity aerobic exercise is associated with higher levels of cortisol in the blood after exercise.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.