Acute effects of two different work-to-rest ratio of high-intensity interval training on BDNF in untrained young men
Question
Do two acute cycling HIIT protocols with different work-to-rest ratios produce different serum BDNF responses in untrained young men?
Summary
In untrained young men, two acute cycling HIIT sessions raised serum BDNF immediately after exercise and returned to baseline by 30 minutes. The 2-min work, 1-min recovery format produced higher lactate and cortisol responses than the 1-min work, 1-min recovery format, but BDNF responses were similar.
Methodology
- Healthy untrained young men
- 12 participants.
- Cycle ergometer.
- Work intervals: 2 min at 85-90% VO2max.
- Recovery: 1 min active recovery at 50-60% VO2max.
- Intensity: 85-90% VO2max.
- About 35 min including warm-up.
- Single acute condition.
- One session.
- Randomized crossover acute exercise study
- BDNF, Blood lactate, and Cortisol were tracked.
Outcomes
BDNF
Both HIIT protocols increased BDNF immediately after exercise, with return to baseline by 30 minutes.
Time effect p=0.001; group p=0.164; time x group p=0.755.
Lactate
Lactate increased after both protocols and was higher after the 2:1 protocol.
Group p=0.009; time x group p=0.017.
Cortisol
Cortisol rose after both protocols and remained higher at 30 minutes after the 2:1 protocol.
Time p=0.001; group p=0.034; interaction p=0.013.
Insights
- Work-rest ratio can change lactate and cortisol load even when BDNF response is similar.
- Short lab cycling HIIT reached very high RPE in untrained men.
- BDNF evidence here is acute and transient.
Limitations
- Small sample
- Male-only participants
- Acute biomarker design
- No long-term cognitive or training outcomes
- Laboratory cycling limits app translation
Safety
- No adverse-event results were reported.