Physiological Responses between African-American and Caucasian Males Before, During and After Normobaric Hypoxic Exercise

Abstract

To further elucidate physiological and cognitive performance differences between African-American (AA) and Caucasian individuals (CAU) before, during or after hypoxic and normoxic exercise. Twelve college aged (18–25) apparently healthy African-American (six volunteers) and Caucasian (six subjects) males took part in two trials consisting of normobaric normoxia and normobaric hypoxia (12% oxygen). Each subject cycled at 50% of their altitude adjusted VO2max (−26% of normoxia VO2max) for one hour after a two-hour baseline. Subjects were monitored for cerebral and arterial O2 saturation, as well as the Trail Making Test A and B (TMT) psychomotor performance. Arterial saturation proved to be significantly higher in AA (86.0±4.7) compared to CAU (79.5±4.8) during the first 60 minutes of exposure to hypoxia at rest (p=0.039), but not during exercise. However, cerebral oxygenation to the left frontal lobe was decreased near the conclusion and in 30 minutes after normoxic exercise. TMT B data revealed that CAU (79±12.7) had faster scores than the AA subjects (98±25.1) at all time points and was significantly different at the 115-minute time point of the hypoxic trial (p=0.024). The data suggests that before, during and after normobaric normoxia and hypoxia trial there is a differential response between AA and CAU in regards to arterial and cerebral oxygenation, as well as psychomotor tests.

Sensitivity of cognitive function tests to acute hypoxia in healthy subjects: a systematic literature review

“…Eighteen studies were performed in a hypoxic chamber ( Asmaro et al, 2013 ; Kim et al, 2015 ; Seo et al, 2015 ; Lefferts et al, 2016 ; Legg et al, 2016 ; Valk et al, 2016 ; Beer et al, 2017 ; Feeback et al, 2017 ; Seo et al, 2017 ; Decroix et al, 2018 ; Reményi et al, 2018 ; Gerhart et al, 2019 ; Williams et al, 2019 ; Seech et al, 2020 ; Blacker and McHail, 2021 ; Blacker and McHail, 2022 ; Chroboczek et al, 2022 ; Falla et al, 2022 ; Kerr et al, 2022 ), 16 with a breathing mask that induced hypoxia ( Turner et al, 2015a ; Noble et al, 1993 ; Ochi et al, 2018 ; Malle et al, 2016 ; Lei et al, 2019 ; Caldwell et al, 2018 ; Hewett et al, 2010 ; Legg et al, 2012 ; Ogoh et al, 2018 ; Stepanek et al, 2013 ; Nakata et al, 2017 ; Loprinzi et al, 2019 ; Kourtidou-Papadeli et al, 2008 ; Turner et al, 2015b ), two studies were performed at altitude ( Wang et al, 2013 ; Davranche et al, 2016 ), one both at altitude and in a chamber ( Kammerer et al, 2018 ), and one both in a chamber and with a breathing mask ( Rossetti et al, 2021 ). The exposure duration ranged from 10 min to 6.5 h with 92% of studies using durations of <3 h. The data points obtained were divided into exposure to normobaric hypoxia (133; 67%) and hypobaric hypoxia (66; 33%).…”

Muscle Oxygen Delivery in the Forearm and in the Vastus Lateralis Muscles in Response to Resistance Exercise: A Comparison Between Nepalese Porters and Italian Trekkers

“…Despite evidence of physiological differences among ethnic groups (Wu and Kayser, 2006), little is known about the differences in response to hypoxic conditioning. In this regard, Feeback et al (2017) investigated arterial saturation and cerebral oxygenation in response to exercise hypoxia comparing African-American and Caucasian males, highlighting a differential response between the two ethnic groups. Simonson et al (2015) highlighted the advantage of Tibetans in exerting higher exercise capacity at altitude to be supported by enhanced muscle O2 transport capacity.…”