PMID 34882027

Research
All papers

Cerebrovascular response to an acute bout of low-volume high-intensity interval exercise and recovery in young healthy adults

Whitaker AA, Aaron SE, Kaufman CS, Kurtz BK, Bai SX, Vidoni ED, Montgomery RN, Billinger SA

Question

How does middle cerebral artery blood velocity respond during and after a 10-minute low-volume HIIT bout in young healthy adults?

Summary

In 24 analyzed young healthy adults, a 10-minute recumbent-stepper HIIT bout increased middle cerebral artery velocity during exercise, lowered it immediately after exercise, and returned it to baseline by 30 minutes. No adverse events occurred and all participants maintained the prescribed workload.

Methodology

  • Young healthy adults
  • 24 participants.
  • Recumbent stepper.
  • Work intervals: 1 minute at about 70% estimated Wattmax.
  • Recovery: 1 minute active recovery at about 10% estimated Wattmax.
  • Intensity: High intervals averaged 134 +/- 37 W and 71 +/- 5% estimated Wattmax.
  • 10 minutes plus 2-minute cool-down.
  • Single session.
  • Single session.
  • Acute single-group physiological study
  • Middle cerebral artery velocity, Mean arterial pressure, Cerebrovascular conductance, and Safety and completion were tracked.

Outcomes

MCAv during HIIT

MCAv rose above baseline during HIIT rather than decreasing as hypothesized.

MCAv higher than baseline during minutes 1-10, p<=0.003.

Mixed

MCAv recovery

MCAv was lower immediately after exercise and returned to baseline by 30 minutes.

Immediate post vs baseline p<0.001; 30-minute post p=0.47.

Mixed

MAP

MAP increased during HIIT and returned to baseline in recovery.

During HIIT p<0.001; immediate post p=0.25; 30-minute post p=0.12.

Mixed

Safety completion

No adverse events occurred and all analyzed participants maintained the workload.

Improved

Insights

  • A 10-minute 1:1 interval format can be tolerated by screened young adults under supervision.
  • Add a cool-down after short hard intervals.
  • Do not translate acute MCAv changes into consumer benefit claims.

Limitations

  • Acute single-group design.
  • Young healthy low-risk sample.
  • No non-exercise control condition.
  • MCA diameter was not directly measured.
  • Exercise intensity was based on estimated maximal workload.
  • PETCO2 measurement may have influenced breathing.

Safety

  • No adverse events occurred.
  • All analyzed participants maintained prescribed workload.
  • One participant was excluded because transcranial Doppler signal was lost.