Exercise‐induced elevations in cerebral blood velocity are greater in running compared to cycling at higher intensities

Abstract

The optimal exercise intensity and modality for maximizing cerebral blood flow (CBF) and hence potential exposure to positive, hemodynamically derived cerebral adaptations is yet to be fully determined. This study compared CBF velocity responses between running and cycling across a range of exercise intensities. Twenty‐six participants (12 females; age: 26 ± 8 years) completed four exercise sessions; two mode‐specific maximal oxygen consumption (VO 2max ) tests, followed by (order randomized) two incremental exercise protocols (3‐min stages at 35%, 50%, 65%, 80%, 95% VO 2max ). Continuous measures of middle cerebral artery velocity (MCAv), oxygen consumption, end‐tidal CO 2 (P ET CO 2 ), and heart rate were obtained. Modality‐specific MCAv changes were observed for the whole group (interaction effect: p = .01). Exercise‐induced increases in MCAv mean during cycling followed an inverted‐U pattern, peaking at 65% VO 2max (Δ12 ± 7 cm/s from rest), whereas MCAv mean during running increased linearly up to 95% VO 2max (change from rest: Δ12 ± 13 vs. Δ7 ± 8 cm/s for running vs. cycling at 95% VO 2max ; p = .01). In contrast, both modalities had an inverted‐U pattern for P ET CO 2 changes, although peaked at different intensities (running: 50% VO 2max , Δ6 ± 2 mmHg; cycling: 65% VO 2max , Δ7 ± 2 mmHg; interaction effect: p = .01). Further subgroup analysis revealed that the running‐specific linear MCAv mean response was fitness dependent (Fitness*modality*intensity interaction effect: p = .04). Above 65% VO 2max , fitter participants ( n = 16; male > 45 mL/min/kg and female > 40 mL/min/kg) increased MCAv mean up to 95% VO 2max , whereas in unfit participants ( n = 7, male < mL/min/kg and female < 35 mL/min/kg) MCAv mean returned toward resting values. Findings demonstrate that modality‐ and fitness‐specific profiles for MCAv mean are seen at exercise intensities exceeding 65% VO 2max .

The Acute Cardiorespiratory and Cerebrovascular Response to Resistance Exercise

“…The inherent complexity of CBF regulation is compounded by the VM and associated mechanical effects of perturbations in ICP during RE and rowing. Similarly, running produces rhythmic oscillations in blood pressure and MCAv [ 129 ], produced by interference between stride frequency and heart rate [ 130 ]. Whilst the hierarchy of cerebrovascular regulators still exists during RE (i.e.…”

Effect of Acute Cardiovascular Exercise on Cerebral Blood Flow: A Systematic Review

“…First, included studies focused on various exercise interventions including cycling (electronically braked cycle ergometer; n = 40), running (treadmill; n = 7), stepping exercise (recumbent stepper; n = 4), and other HIIE (n = 2). Note that one study used both treadmill- running and cycling on an electronically braked cycle ergometer as exercise intervention to test the effects of exercise on cerebral perfusion (Furlong et al, 2020). For example, Sato and colleagues (2011) observed a significant increase in MCA V mean from rest to 80% VO2peak followed by a significant decrease in MCA V mean from 80% VO2peak during a cycling intervention.…”

“…TCD data suggests that cerebral blood flow may significantly increase as a result of acute aerobic exercise (Billinger et al, 2017; Burma et al, 2020; Ellis et al, 2017; Fisher et al, 2008; Fisher et al, 2013; Furlong et al, 2020; Imhoff et al, 2017; Klein et al, 2019; Labrecque et al, 2020; Lyngeraa et al, 2013; Parfitt et al, 2017; Perdomo et al, 2019; Pugh et al, 2015; Rattray et al, 2017; Sato et al, 2011; Smith et al, 2019; Witte et al, 2019), with only a single study showing that CBF remained unchanged (Burma et al, 2020). Specifically, 17 papers reported a significant increase in middle cerebral artery blood flow mean velocity (MCAV) (Billinger et al, 2017; Burma et al, 2020; Ellis et al, 2017; Fisher et al, 2008; Fisher et al, 2013; Furlong et al, 2020; Imhoff et al, 2017; Klein et al, 2019; Labrecque et al, 2020; Lyngeraa et al, 2013; Parfitt et al, 2017; Perdomo et al, 2019; Pugh et al, 2015; Rattray et al, 2017; Sato et al, 2011; Smith et al, 2019; Witte et al, 2019). Additionally, Labrecque and colleagues (2020) and Pugh and colleagues (2015) reported a significant increase in posterior cerebral artery mean blood velocity (PCAv mean ) during exercise.…”

“…Lastly, 3.8 % of included studies employed a form of HIIT that does not include cycling, running on a treadmill, or stepping. In their study, Furlong and colleagues (2020) decided to use both cycling on an electronically braked cycle ergometer and treadmill running.…”

“…Billaut et al, 2010Billinger et al, 2017Billinger et al, 2021Braz et al, 2017Burma et al, 2020Ellis et al, 2017Faulkner et al, 2016Fisher et al, 2008Fisher et al, 2013Furlong et al, 2020Giles et al, 2014Hartmann et al, 2020Hiura et al, 2009Hiura et al, 2013Hiura et al, 2018Ichinose et al, 2020Imhoff et al, 2017Imray et al, 2005Klein et al, 2019Koike et al, 2004aKoike et al, 2004bKoike et al, 2006Labrecque et al, 2020 Lyngeraa et al, 2013MacIntosh et al, 2017Malik et al, 2018Matsukawa et al, 2015Monroe et al, 2016Neary et al, 2008Parfitt et al, 2017Perdomo et al, 2019Pontifex et al, 2018Pugh et al, 2015Rattray et al, 2017 …”