Comparable Blood Velocity Changes in Middle and Posterior Cerebral Arteries During and Following Acute High‐Intensity Exercise in Young Fit Women

Abstract

The influence of high‐intensity exercise training (HIIT) on cerebral blood flow (CBF) regulation remains unclear. HIIT induces surges in mean arterial pressure (MAP), which could be transmitted to the brain, especially early after exercise onset. The aims of this study were to 1) describe regional CBF changes during and following 30 s of high‐intensity exercise and; 2) examine whether dynamic cerebral autoregulation (dCA) is associated with CBF changes. Ten women (age: 26 ± 6 yrs; VO2max: 48.6 ± 3.8 ml×kg×min−1) cycled for 30 s at the workload reached at VO2max followed by 3 min of passive recovery. dCA was characterized using transfer function analysis of forced oscillations induced by repeated squat‐stands (0.05 and 0.10 Hz). Middle (MCAvmean) and posterior cerebral artery mean blood velocities (PCAvmean; transcranial Doppler), MAP (finger photoplethysmography) and end‐tidal carbon dioxide partial pressure (PETCO2; gaz analyzer) were measured. MCAvmean (+19 ± 10%) and PCAvmean (+21 ± 14%) increased early after exercise onset, returning toward baseline values afterwards. MAP increased throughout exercise (p<0.0001). PETCO2 initially decreased by 3 ±2 mmHg (p<0.0001) before returning to baseline values at end‐exercise. During recovery, MCAvmean (+43 ±15%), PCAvmean (+42 ± 15%) and PETCO2 (+11 ± 3 mmHg; p<0.0001) increased. TFA gain was higher in the MCA (p < 0.0001). Other dCA metrics were comparable between arteries and unrelated to exercise‐induced cerebral blood velocity changes. In young fit women, blood velocity changes during and following a 30‐s high‐intensity exercise are comparable between MCA and PCA and unrelated to dCA. Support or Funding Information L.L. and S.I. are supported by a doctoral training scholarship from the Fonds de recherche du Québec – Santé (FRQS).

Cerebral Hemodynamic and Neurotrophic Factor Responses Are Dependent on the Type of Exercise

“…While growing evidence supports the utilization of interval-based exercise, it is important to consider the potential risks of these strategies against the physiological benefits they may provide ( Lucas et al, 2015 ; Labrecque et al, 2020 ). Encouragingly, recent studies into the risk between interval-based and traditional continuous exercise protocols for cardiovascular disease cohorts have shown that the two are of similar risk ( Rognmo et al, 2012 ; Wewege et al, 2018 ).…”

“…Despite this, studies focusing on the cerebrovascular responses to these strategies are limited in number. While current evidence indicates comparable middle cerebral artery velocity (MCAv) responses between continuous and interval-based moderate intensity exercise ( Klein et al, 2019 ), MCAv has been shown to be suppressed over the course of a single 30 s all-out sprint bout, followed by a marked elevation in MCAv during recovery ( Curtelin et al, 2018 ; Labrecque et al, 2020 ). This reduction in response to high intensity interval-based strategies is in contrast to responses within the peripheral vasculature ( Ramos et al, 2015 ), likely driven by the unique response of the cerebrovasculature to exercise-induced hyperventilatory hypocapnia ( Ogoh and Ainslie, 2010 ), as well as differences in the regulatory responses to elevated systemic flow and blood pressure ( Brassard et al, 2017 ; Ogoh et al, 2018 ; Calverley et al, 2020 ).…”

“…Understanding this relationship is particularly important as research increasingly supports short (30-60 s) sprint interval training (SIT) protocols at supramaximal intensities, rather than longer (∼4 min) high intensity efforts performed in guideline-based high intensity interval training (HIIT) (Weston et al, 2014). While the current literature demonstrates the complex relationship between SIT and measures of cerebral hemodynamics (Curtelin et al, 2018;Labrecque et al, 2020), it is not clear whether these responses change over multiple bouts as is typical in training interventions, nor how SIT-and HIIT-based strategies may differ in their response.…”

Effects of high intensity interval exercise on cerebrovascular function: A systematic review

“…The search methods resulted in 67 articles. After removal of duplicates, 15 [ 45 , 46 , 50 , 53 , 60 – 69 ] articles were identified in PubMed and 5 [ 47 , 51 , 70 – 72 ] new articles in CINAHL. During the initial screening of titles/abstracts, 11 articles were excluded due to HIIE not being the primary experimental protocol performed (n = 6), studies not measuring cerebral arteries (n = 4) and an animal study (n = 1).…”

Post-Stroke Physical Activity Improves Middle Cerebral Artery Dynamic Response

“…4,29 Our data extend current knowledge regarding cerebrovascular response to exercise and is timely given the increased interest and concern for the role of high-intensity interval training on cerebrovascular response, especially for those with neurological conditions such as stroke. 28,30,31 The authors of these review papers 28,31 and a recent study describing the cerebrovascular response to a 30-second bout of high intensity exercise 30 suggest that caution should be taken when implementing this type of protocol, as the evidence for safety with respect to the brain and its delicate cerebrovasculature has not been tested. A recently published clinical practice guideline for physical therapy suggests higher locomotor intensities benefit walking speed and endurance in chronic stroke 32 .…”