PMID 40470031

Research
All papers

Effects of high-intensity interval training and moderate-intensity continuous training on the functioning of attentional networks and heart rate variability in healthy young adults

Yue T, Li F, Wang Y

Question

How do acute HIIT and moderate continuous cycling affect alerting, orienting, executive control, and HRV in healthy young adults?

Summary

In 36 healthy college students, a single cycling HIIT session improved overall reaction time and executive-control performance on an attention-network task compared with rest and, for executive control, compared with moderate continuous exercise. However, HIIT also reduced the phasic alerting score versus rest and did not improve orienting. HRV reductions suggested stronger arousal/parasympathetic withdrawal after HIIT, which correlated with alerting and executive-control changes.

Methodology

  • Healthy college students without regular exercise habits.
  • 36 participants.
  • Cycle ergometer.
  • Work intervals: 1 minute at 100% Wpeak.
  • Recovery: 1 minute active recovery at 20% Wpeak.
  • Intensity: 100% Wpeak, approximately 90% HRmax, with recovery at 20% Wpeak.
  • 20 minutes HIIT plus 2-minute warm-up and 2-minute cool-down.
  • Single acute session.
  • Single session in crossover protocol.
  • Randomized within-subject crossover acute experiment
  • Alerting function, Orienting function, Executive control function, and Heart rate variability were tracked.

Outcomes

Overall ANT-I reaction time

HIIT produced faster overall RTs than rest.

Exercise main effect p=.003; HIIT vs CON p=.003.

Improved

Alerting function

HIIT reduced phasic alerting function compared with rest.

p=.017, Cohen d=.42.

Safety concern

Orienting function

Neither HIIT nor MICT significantly changed orienting function.

Exercise main effect p=.138.

No clear change

Executive control

HIIT improved executive control compared with both MICT and rest.

HIIT vs MICT p=.002, d=.57; HIIT vs CON p=.001, d=.62.

Improved

HRV

HIIT produced greater immediate and task-related reductions in LnRMSSD and LnHF than MICT and rest.

LnRMSSD and LnHF exercise effects p<.001.

Mixed

HRV correlations

After HIIT, LnRMSSD changes correlated with alerting and executive-control functions.

Immediate LnRMSSD with alerting r=.554, p=.001; with executive control r=.412, p=.016; task-related r=.424 and r=.356.

Mixed

Insights

  • Acute HIIT may sharpen some executive-control performance but can also change alerting/vigilance dynamics.
  • Cognition effects are domain-specific; do not frame HIIT as globally improving attention.
  • Arousal and recovery timing matter when placing HIIT before cognitively demanding tasks.

Limitations

  • Acute single-session design.
  • Healthy young adults only.
  • Mechanisms inferred from HRV only; no biochemical markers.
  • Laboratory cycling protocol may not transfer to bodyweight HIIT.
  • No long-term attention outcomes.

Safety

  • No adverse events were reported in the the paper.
  • Participants completed health screening and were excluded for cardiovascular disease, smoking, mental illness history, and other factors.
  • HRV data for two participants were missing because of equipment malfunction.