title: Acute Supramaximal Exercise Increases the Brain Oxygenation in Relation to Cognitive Workload.
abstract: Single bout of exercise can improve the performance on cognitive tasks. However, cognitive responses may be controversial due to different type, intensity, and duration of exercise. In addition, the mechanism of the effect of acute exercise on brain is still unclear. This study was aimed to investigate the effects of supramaximal exercise on cognitive tasks by means of brain oxygenation monitoring. The brain oxygenation of Prefrontal cortex (PFC) was measured on 35 healthy male volunteers via functional near infrared spectroscopy (fNIRS) system. Subjects performed 2-Back test before and after the supramaximal exercise wingate anerobic test (WAnT) lasting 30-s on cycle ergometer. The PFC oxygenation change evaluation revealed that PFC oxygenation rise during post-exercise 2-Back task was considerably higher than those in pre-exercise 2-Back task. In order to describe the relationship between oxygenation change and exercise performance, subjects were divided into two groups as high performers (HP) and low performers (LP) according to their peak power values (PP) obtained from the supramaximal test. The oxy-hemoglobin (oxy-Hb) values were compared between pre- and post-exercise conditions within subjects and also between subjects according to peak power. When performers were compared, in the HP group, the oxy-Hb values in post-exercise 2-Back test were significantly higher than those in pre-exercise 2-Back test. HP had significantly higher post-exercise oxy-Hb change (Δ) than those of LP. In addition, PP of the total group were significantly correlated with Δoxy-Hb.The key findings of the present study revealed that acute supramaximal exercise has an impact on the brain oxygenation during a cognitive task. Also, the higher the anerobic PP describes the larger the oxy-Hb response in post-exercise cognitive task. The current study also demonstrated a significant correlation between peak power (exercise load) and post-exercise hemodynamic responses (oxy-, deoxy- and total-Hb). The magnitude of this impact might be related with the physical performance capacities of the individuals. This can become a valuable parameter for future studies on human factor.
authors.affiliation: Department of Physiology, Faculty of Medicine, Dokuz Eylul UniversityIzmir, Turkey; Department of Biophysics, Faculty of Medicine, Dokuz Eylul UniversityIzmir, Turkey.
authors.forename: Cem Seref
authors.initials: CS
authors.lastname: Bediz
authors.affiliation: Department of Biophysics, Faculty of Medicine, Dokuz Eylul University Izmir, Turkey.
authors.forename: Adile
authors.initials: A
authors.lastname: Oniz
authors.affiliation: Department of Biophysics, Faculty of Medicine, Dokuz Eylul University Izmir, Turkey.
authors.forename: Cagdas
authors.initials: C
authors.lastname: Guducu
authors.affiliation: Department of Physiology, Faculty of Medicine, Dokuz Eylul University Izmir, Turkey.
authors.forename: Enise
authors.initials: E
authors.lastname: Ural Demirci
authors.affiliation: Department of Biophysics, Faculty of Medicine, Dokuz Eylul University Izmir, Turkey.
authors.forename: Hilmi
authors.initials: H
authors.lastname: Ogut
authors.affiliation: Department of Biophysics, Faculty of Medicine, Dokuz Eylul UniversityIzmir, Turkey; School of Sport Sciences and Technology, Dokuz Eylul UniversityIzmir, Turkey.
authors.forename: Erkan
authors.initials: E
authors.lastname: Gunay
authors.affiliation: School of Sport Sciences and Technology, Dokuz Eylul University Izmir, Turkey.
authors.forename: Caner
authors.initials: C
authors.lastname: Cetinkaya
authors.affiliation: Department of Biophysics, Faculty of Medicine, Dokuz Eylul University Izmir, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Ozgoren
keywords: N-back test; PFC; cognition and exercise; fNIRS; human factor