# Affective Reactivity to a Single Bout of High-Intensity Interval Training in Schizophrenia: A Randomized Controlled Trial

PMID: 42077795
Journal: Schizophrenia bulletin open
Published: 2026
Authors: Sanden M, Pauck Bernhardsen G, Hanssen-Bauer K, Høye A, Johnsen E, Morken G, Nygård M, Abel Engh J

## Question

Does one supervised HIIT session elicit greater immediate positive and negative affect changes than an active control condition in people with schizophrenia?

## Summary

In stable outpatients with schizophrenia, a single mid-program supervised 4x4 treadmill HIIT session did not improve immediate affect more than a socially engaging low-intensity video-game control. Both groups showed favorable affective shifts, and higher baseline symptoms were linked with lower pre-session positive affect.

## Population

- Sixty-nine adult outpatients with schizophrenia completed pre/post PANAS at session 12.
- Sample size: 69
- Age: Mean 38.4 +/- 14.6 years
- Sex: 61% men
- Fitness level: VO2max about 30 ml/kg/min
- Health status: Clinically stable schizophrenia outpatients; 97% receiving antipsychotic medication

## Methodology

- Randomized observer-blinded parallel-group controlled trial analysis
- 12-week intervention; affect measured around session 12
- Outpatient clinical exercise intervention in Norway
- Randomized and controlled study design.

## Protocol

- Treadmill 4x4 HIIT.
- Modality: Treadmill walking/running.
- Work intervals: 4 minutes.
- Recovery: 3 minutes active recovery.
- Sets or repetitions: 4 intervals.
- Intensity: 85%-95% HRmax work, 70% HRmax recovery.
- Session duration: About 42 minutes.
- Frequency: 2 sessions/week.
- Program length: 12 weeks.
- Progression: Affect measured at session 12; broader progression not described in this paper.
- Active control video gaming.
- Modality: Nintendo Wii Sports tennis.
- Intensity: Low intensity with minor HR and movement increases.
- Session duration: About 45 minutes.
- Frequency: 2 sessions/week.
- Program length: 12 weeks.

## Outcomes

### Positive affect
Status: mixed
HIIT increased positive affect within group, but not significantly more than active control.

Between-group B=1.53, 95% CI -0.90 to 3.96, p=.221; HIIT within-group delta 3.17, p=.001.

### Negative affect
Status: mixed
Active control reduced negative affect within group; HIIT did not significantly differ from control.

Between-group B=0.90, 95% CI -0.94 to 2.75, p=.342; ACC within-group delta -2.09, p=.002; HIIT p=.090.

### Symptoms
Status: mixed
Higher apathy, depressive symptoms, and negative symptoms were associated with lower pre-session positive affect; exploratory moderation suggested greater HIIT positive-affect gains with higher negative symptoms.

AES B=-0.53 p<.001; CDSS B=-0.85 p<.001; PANSS-Negative B=-0.50 p=.002; Group x Time x PANSS-Negative B=0.38, p=.040 unadjusted.

## Practical Insights

- Immediate affect improvements after HIIT may not exceed those from structured, socially engaging low-intensity activity.
- Affective check-ins before and after sessions may be useful, especially in populations with motivational symptoms.

## Limitations

- Self-report PANAS only.
- Immediate single-session affect analysis at the midpoint of a longer program.
- RPE and cardiovascular response were not assessed in this affect analysis.
- Stable outpatient schizophrenia sample limits generalizability.
- Higher-order moderation analyses were exploratory and underpowered.

## Safety And Adherence

- Staff were present to ensure safety and engagement; no adverse event details were reported in this affect paper.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/42077795/) (pubmed)
- [DOI](https://doi.org/10.1093/schizbullopen/sgag004) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13131230/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.