Effects of Bicycle Ergometer Exercise on Cerebral Blood Flow Velocity and Electroencephalogram Response in Normoxia and Hypoxia

Seong Dae Kim; Myung Wha Kim; Il Gyu Jeong

doi:10.15384/kjhp.2019.19.1.59

Korean J Health Promot > Volume 19(1); 2019 > Article

Kim, Kim, and Jeong: Effects of Bicycle Ergometer Exercise on Cerebral Blood Flow Velocity and Electroencephalogram Response in Normoxia and Hypoxia

Original Article

Korean Journal of Health Promotion 2019;19(1):59-67.

Published online: March 31, 2019

DOI: https://doi.org/10.15384/kjhp.2019.19.1.59

Effects of Bicycle Ergometer Exercise on Cerebral Blood Flow Velocity and Electroencephalogram Response in Normoxia and Hypoxia

Seong Dae Kim¹, Myung Wha Kim², Il Gyu Jeong¹

¹Department of Sports Science, Hannam University, Daejeon, Korea.

²Department of Sports Rehabilitation, Woosong University, Daejeon, Korea.

Corresponding author: Il Gyu Jeong, PhD. Department of Sports Science, Hannam University, 70 Hannam-ro, Daedeok-gu, Daejeon 34430, Korea.
Tel: +82-42-629-7653, Fax: +82-42-629-8402, jig1229@hanmail.net

Received February 26, 2019 Revised March 21, 2019 Accepted March 22, 2019

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

ABSTRACT

Background

The cerebral blood flow velocity (CBFV) has been known to increase in response to acute hypoxia. However, how CBFV might respond to exercise in hypoxic conditions and be associated with electroencephalogram (EEG) remains unclear. The purpose of this study was to evaluate the effect of exercise in hypoxic conditions corresponding to altitudes of 4,000 m on CBFV and EEG.

Methods

In a randomized, double-blind, balanced crossover study, ten healthy volunteers (19.8±0.4 years) were asked to perform the incremental bicycle ergometer exercise twice in hypoxic and control (sea level) conditions with a 1-week interval, respectively. Exercise intensity was set initially at 50 W and increased by 25 W every 2 minutes to 125 W. Acute normobaric hypoxic condition was maintained for 45 minutes using low oxygen gas mixture. CBFV in the middle cerebral artery (MCA) and EEG were measured at rest 5 minutes, rest 15 minutes, immediately after exercise, and 15 minutes recovery using transcranial-Doppler sonography and EEG signal was recorded from 6 scalp sites leading to analysis of alpha and beta wave relative activities. All data were analyzed using two-way repeated-measures analysis of variance and Pearson's correlation.

Results

CBFV in the MCA in the hypoxic condition was significantly higher than that in the control condition at rest 5 minutes (83±9 vs. 69±9 cm/s, P<0.01), rest 15 minutes (87±8 vs. 67±7 cm/s, P<0.001), immediately after exercise (112±9 vs. 97±9 cm/s, P<0.01), and 15 minutes recovery (91±11 vs. 74±7 cm/s, P<0.01). However, no significant correlation was found between the changes of CBFV and EEG wave activities.

Conclusions

These results suggest that the drastic change of CBFV observed during exercise with hypoxia might appear independently with EEG wave activities.

Keywords: Exercise, Hypoxia, Cerebrovascular circulation, Electroencephalogram

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