title: The relationship between exercise intensity, cerebral oxygenation and cognitive performance in young adults.
abstract: OBJECTIVE
  To assess the relationship between exercise intensity, cerebral HbO2 and cognitive performance (Executive and non-Executive) in young adults.
  
  
  METHODS
  We measured reaction time (RT) and accuracy, during a computerized Stroop task, in 19 young adults (7 males and 12 females). Their mean ± SD age, height, body mass and body mass index (BMI) were 24 ± 4 years, 1.67 ± 0.07 m, 72 ± 14 kg and 25 ± 3 kg m(-2), respectively. Each subject performed the Stroop task at rest and during cycling at exercise of low intensity [40% of peak power output (PPO)], moderate intensity (60% of PPO) and high intensity (85% of PPO). Cerebral oxygenation was monitored during the resting and exercise conditions over the prefrontal cortex (PFC) using near-infrared spectroscopy (NIRS).
  
  
  RESULTS
  High-intensity exercise slowed RT in both the Naming (p = 0.04) and the Executive condition (p = 0.04). The analysis also revealed that high-intensity exercise was associated with a decreased accuracy when compared to low-intensity exercise (p = 0.021). Neuroimaging results confirm a decrease of cerebral oxygenation during high-intensity exercise in comparison to low- (p = 0.004) and moderate-intensity exercise (p = 0.003). Correlations revealed that a lower cerebral HbO2 in the prefrontal cortex was associated with slower RT in the Executive condition only (p = 0.04, g = -0.72).
  
  
  CONCLUSIONS
  Results of the present study suggest that low to moderate exercise intensity does not alter Executive functioning, but that exercise impairs cognitive functions (Executive and non-Executive) when the physical workload becomes heavy. The cerebral HbO2 correlation suggests that a lower availability of HbO2 was associated with slower RT in the Executive condition only.
authors.affiliation: Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Laboratoire LESCA, 4565, Chemin Queen-Mary, Montréal, H3W 1W5, QC, Canada. said.mekary@gmail.com.|Département de Kinésiologie, Université de Montréal, CP 6128, succ. Centre-ville, Montréal, H3C 3J7, QC, Canada. said.mekary@gmail.com.
authors.forename: Saïd
authors.initials: S
authors.lastname: Mekari
authors.affiliation: Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Laboratoire LESCA, 4565, Chemin Queen-Mary, Montréal, H3W 1W5, QC, Canada.|Département de Psychologie, Université de Québec à Montreal, C.P. 8888 succ. Centre-ville, Montréal, H3C 3P8, QC, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Fraser
authors.affiliation: Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Laboratoire LESCA, 4565, Chemin Queen-Mary, Montréal, H3W 1W5, QC, Canada.|Département de Kinésiologie, Université de Montréal, CP 6128, succ. Centre-ville, Montréal, H3C 3J7, QC, Canada.|Faculté des Sciences du Sport, Laboratoire MOVE (EA 6314), Université de Poitiers, 8, allée Jean Monnet, 86000, Poitiers, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bosquet
authors.affiliation: Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Laboratoire LESCA, 4565, Chemin Queen-Mary, Montréal, H3W 1W5, QC, Canada.|Département de Génie Biomédical, École Polytechnique, CP 6079, succ. Centre-ville, Montréal, H3C 3A7, QC, Canada.
authors.forename: Clément
authors.initials: C
authors.lastname: Bonnéry
authors.affiliation: Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Laboratoire LESCA, 4565, Chemin Queen-Mary, Montréal, H3W 1W5, QC, Canada.|Département de Psychologie, Université de Québec à Montreal, C.P. 8888 succ. Centre-ville, Montréal, H3C 3P8, QC, Canada.
authors.forename: Véronique
authors.initials: V
authors.lastname: Labelle
authors.affiliation: Département de Génie Biomédical, École Polytechnique, CP 6079, succ. Centre-ville, Montréal, H3C 3A7, QC, Canada.|Centre de recherche, Institut de Cardiologie de Montréal, 5000, rue Bélanger, Montréal, H1T 1C8, QC, Canada.
authors.forename: Philippe
authors.initials: P
authors.lastname: Pouliot
authors.affiliation: Département de Génie Biomédical, École Polytechnique, CP 6079, succ. Centre-ville, Montréal, H3C 3A7, QC, Canada.|Centre de recherche, Institut de Cardiologie de Montréal, 5000, rue Bélanger, Montréal, H1T 1C8, QC, Canada.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lesage
authors.affiliation: Centre de Recherche, Institut Universitaire de Gériatrie de Montréal, Laboratoire LESCA, 4565, Chemin Queen-Mary, Montréal, H3W 1W5, QC, Canada.|PERFORM Centre, Concordia University, 7200 Sherbrooke St. W., Montreal, QC, H4B 1R6, Canada.
authors.forename: Louis
authors.initials: L
authors.lastname: Bherer
mesh_terms: D000328:Adult; D001921:Brain / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D002560:Cerebrovascular Circulation; D003071:Cognition; D015444:Exercise; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D010101:Oxygen Consumption
chemical_list: D006454:Hemoglobins
keywords: Cerebral HbO2; Hyperventilation; Near-infrared spectroscopy; Peak power output; Reaction time