PMID 35846013

Research
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A Shorter-Bout of HIIT Is More Effective to Promote Serum BDNF and VEGF-A Levels and Improve Cognitive Function in Healthy Young Men

Li Q, Zhang L, Zhang Z, Wang Y, Zuo C, Bo S

Question

Do 20-minute and 30-minute acute HIIT bouts differ in effects on serum BDNF, VEGF-A, stress hormones, and cognitive performance?

Summary

In 12 active healthy young men, a 20-minute cycling HIIT bout improved several short-term cognitive measures and acutely increased serum BDNF, while a 30-minute bout produced more lactate, higher perceived exertion, and less favorable cognitive and hormonal responses.

Methodology

  • Active healthy right-handed young men from a university setting.
  • 12 participants.
  • Cycle ergometer.
  • Work intervals: 1 minute.
  • Recovery: 1 minute active recovery.
  • Intensity: 85% VO2peak work, 25% VO2peak recovery.
  • 20-minute interval block plus 5-minute warm-up and 5-minute cooldown.
  • Single acute bout.
  • Single session.
  • Randomized crossover acute exercise study
  • Serum BDNF, Serum VEGF-A, Hormonal stress, and Cognitive performance were tracked.

Outcomes

BDNF

BDNF increased immediately after the 20-minute bout but not after the 30-minute bout.

20-min: 21.29 +/- 1.17 to 26.66 +/- 1.32, p<0.001; 30-min decreased below baseline at 30 min, p=0.013.

Improved

VEGF-A

VEGF-A rose immediately after both bouts, then returned to baseline after 20 minutes and fell below baseline after 30 minutes.

Immediate increases in both conditions; below baseline after 30-min bout at 30 minutes.

Mixed

Stroop RT

The 20-minute bout shortened several Stroop reaction times; the 30-minute bout did not improve reaction time.

20-min improved congruent and neutral RT immediately and at 30 min, and incongruent RT immediately p=0.043.

Improved

Digit span

Digit span improved after the 20-minute bout but not after the 30-minute bout.

DST-F improved immediately and 30 min; DST-B improved immediately after 20-min HIIT.

Improved

RPE

Perceived exertion was higher after the 30-minute bout.

RPE 14.417 +/- 1.165 for 20-min and 16.417 +/- 0.996 for 30-min.

Safety concern

Insights

  • More HIIT volume was not better for short-term cognition and biomarker response in this small acute study.
  • A 20-minute 1:1 cycling interval block at 85% VO2peak showed more favorable acute responses than a 30-minute block.
  • The biomarker findings should be used cautiously because they are surrogate outcomes from a small homogeneous sample.

Limitations

  • Very small sample of 12 young men.
  • Acute study only.
  • Only selected cognitive tasks were assessed.
  • Only neurotrophins and hormones were measured; neural activation was not measured.
  • Right-handed active young men only.

Safety

  • No adverse events were reported in the the paper.
  • Participants were screened for health status and smoking/alcohol history.