الإنتاج البحثي لأعضاء هيئة التدريس بالكلية V.8 - Flipbook - Page 166
ﺳﺘﯿﻔﺎﻧﻮس ﻓﻮﻟﯿﺎﻧﯿﺘﯿﺲ.د
ﺟﺎﻣﻌﺔ ﻗﻄﺮ- أﺳﺘﺎذ ﻣﺸﺎرك ﺑﻘﺴﻢ اﻟﺘﺮﺑﯿﺔ اﻟﺒﺪﻧﯿﺔ – ﻛﻠﯿﺔ اﻟﺘﺮﺑﯿﺔ
svolianitis@qu.edu.qa
ORCID
0000-0002-4032-9391
Scopus ID
6603708438
(1) Sejersen, C., Volianitis, S., Secher, N.H.(2024). The athlete’s heart: allometric
considerations on published papers and relation to cardiovascular variables. European
Journal of Applied Physiology, 124(5), pp. 1337–1346
To evaluate the morphology of the "athlete's heart", left ventricular (LV) wall thickness (WT) and
end-diastolic internal diameter (LVIDd) at rest were addressed in publications on skiers, rowers,
swimmers, cyclists, runners, weightlifters (n = 927), and untrained controls (n = 173) and related
to the acute and maximal cardiovascular response to their respective disciplines. Dimensions of the
heart at rest and functional variables established during the various sport disciplines were scaled to
body weight for comparison among athletes independent of body mass. The two measures of LV
were related (r = 0.8; P = 0.04) across athletic disciplines. With allometric scaling to body weight,
LVIDd was similar between weightlifters and controls but 7%-15% larger in the other athletic
groups, while WT was 9%-24% enlarged in all athletes. The LVIDd was related to stroke volume,
oxygen pulse, maximal oxygen uptake, cardiac output, and blood volume (r = ~ 0.9, P < 0.05),
while there was no relationship between WT and these variables (P > 0.05). In conclusion, while
cardiac enlargement is, in part, essential for the generation of the cardiac output and thus stroke
volume needed for competitive endurance exercise, an enlarged WT seems important for the
development of the wall tension required for establishing normal arterial pressure in the enlarged
LVIDd.
(2) Volianitis, S., Rasmussen, P., Petersen, N.C., Secher, N.H. (2022). The Effect of
Hyperoxia on Central and Peripheral Factors of Arm Flexor Muscles Fatigue Following
Maximal Ergometer Rowing in Men. Frontiers in Physiology, 13, 828708
Purpose: This study evaluates the effect of hyperoxia on cerebral oxygenation and neuromuscular
fatigue mechanisms of the elbow flexor muscles following ergometer rowing.
Methods: In 11 competitive male rowers (age, 30 ± 4 years), we measured near-infrared
spectroscopy determined frontal lobe oxygenation (ScO2) and transcranial Doppler ultrasound
determined middle cerebral artery mean flow velocity (MCA V mean) combined with maximal
voluntary force (MVC), peak resting twitch force (P tw) and cortical voluntary activation (VATMS)
of the elbow flexor muscles using electrical motor point and magnetic motor cortex stimulation,
respectively, before, during, and immediately after 2,000 m all-out effort on rowing ergometer with
normoxia and hyperoxia (30% O2).
Results: Arterial hemoglobin O2 saturation was reduced to 92.5 ± 0.2% during exercise with
normoxia but maintained at 98.9 ± 0.2% with hyperoxia. The MCA V mean increased by 38% (p
