David Stevens1,2, Mark Halaki3, Chin Moi Chow3, Nicholas O'Dwyer3,4. 1. Discipline of Exercise and Sport Science, Faculty of Health Sciences, The University of Sydney, Sydney, NSW, Australia. david.stevens@flinders.edu.au. 2. Adelaide Institute for Sleep Health - A Flinders Centre for Research Excellence, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia. david.stevens@flinders.edu.au. 3. Discipline of Exercise and Sport Science, Faculty of Health Sciences, The University of Sydney, Sydney, NSW, Australia. 4. School of Exercise Science, Sport and Health, Faculty of Science, Charles Sturt University, Bathurst, NSW, Australia.
Abstract
INTRODUCTION: Studies of cerebral haemodynamics have shown changes with increased exercise intensity, but the patterns have been highly variable and reliable associations with cognitive performance have not been identified. The aim of this study was to examine whether exercise-induced changes in oxygenated haemoglobin (O2Hb) led to changes in concomitant cognitive performance. METHODS: This study examined cardiorespiratory and cerebral haemodynamics during multi-stage exercise from rest to exhaustion, with (Ex + C) and without (Ex) concurrent cognitive performance (Go/No-go task). RESULTS: The presence of the cognitive task affected both cardiorespiratory and cerebral haemodynamics. The patterns in the cerebral haemodynamics during Ex and Ex + C diverged above the respiratory compensation threshold (RCT), but differences were significant only at 100% [Formula: see text], displaying increased deoxygenated haemoglobin (HHb), decreased difference between oxygenated and deoxygenated haemoglobin (HbDiff), and decreased cerebral oxygenation (COx) during Ex + C. More complex haemodynamic trends against intensity during Ex + C suggested that the presence of a cognitive task increases cerebral metabolic demand at high exercise intensities. The levels of O2Hb, HHb, HbDiff and total haemoglobin increased most steeply at intensities around the RCT during both Ex and Ex + C, but these changes were not accompanied by improved cognitive performance. CONCLUSION: The primary hypothesis, that cognitive performance would match changes in O2Hb, was not supported. Small variations in reaction time and response accuracy across exercise intensities were not significant, suggesting that cognitive performance is unaffected by intense short-duration exercise. Our results add further evidence that exercise-induced changes in cerebral haemodynamics do not affect cognitive performance.
INTRODUCTION: Studies of cerebral haemodynamics have shown changes with increased exercise intensity, but the patterns have been highly variable and reliable associations with cognitive performance have not been identified. The aim of this study was to examine whether exercise-induced changes in oxygenated haemoglobin (O2Hb) led to changes in concomitant cognitive performance. METHODS: This study examined cardiorespiratory and cerebral haemodynamics during multi-stage exercise from rest to exhaustion, with (Ex + C) and without (Ex) concurrent cognitive performance (Go/No-go task). RESULTS: The presence of the cognitive task affected both cardiorespiratory and cerebral haemodynamics. The patterns in the cerebral haemodynamics during Ex and Ex + C diverged above the respiratory compensation threshold (RCT), but differences were significant only at 100% [Formula: see text], displaying increased deoxygenated haemoglobin (HHb), decreased difference between oxygenated and deoxygenated haemoglobin (HbDiff), and decreased cerebral oxygenation (COx) during Ex + C. More complex haemodynamic trends against intensity during Ex + C suggested that the presence of a cognitive task increases cerebral metabolic demand at high exercise intensities. The levels of O2Hb, HHb, HbDiff and total haemoglobin increased most steeply at intensities around the RCT during both Ex and Ex + C, but these changes were not accompanied by improved cognitive performance. CONCLUSION: The primary hypothesis, that cognitive performance would match changes in O2Hb, was not supported. Small variations in reaction time and response accuracy across exercise intensities were not significant, suggesting that cognitive performance is unaffected by intense short-duration exercise. Our results add further evidence that exercise-induced changes in cerebral haemodynamics do not affect cognitive performance.
Authors: B J Casey; R J Trainor; J L Orendi; A B Schubert; L E Nystrom; J N Giedd; F X Castellanos; J V Haxby; D C Noll; J D Cohen; S D Forman; R E Dahl; J L Rapoport Journal: J Cogn Neurosci Date: 1997-11 Impact factor: 3.225