Kristof Vandekerckhove1, Ilse Coomans1, Annelies Moerman2, Daniel De Wolf1, Jan Boone3,4. 1. Department of Pediatric Cardiology, Ghent University Hospital, Ghent, Belgium. 2. Department of Anesthesiology, Ghent University Hospital, Ghent, Belgium. 3. Department of Movement and Sports Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium. Jan.boone@ugent.be. 4. Center of Sports Medicine, Ghent University Hospital, Ghent, Belgium. Jan.boone@ugent.be.
Abstract
AIMS: To characterize the oxygenation responses at cerebral and locomotor muscle level to incremental exercise in children and to assess the interrelationship with the pulmonary gas exchange responses. METHODS: Eighteen children (9 boys, 9 girls) (mean age 10.9 ± 1.0 years) performed incremental cycle ramp exercise to exhaustion. The concentration of cerebral and muscle oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin (by means of near-infrared spectroscopy) and pulmonary gas exchange was recorded. Cerebral and muscle O2Hb and HHb values were expressed as functions of oxygen uptake (VO2) and breakpoints were detected by means of double linear model analysis. The respiratory compensation point (RCP) was determined. The breakpoints in cerebral and muscle O2Hb and HHb were compared and correlated to RCP. RESULTS: The subjects reached peak power output of 105 ± 18 W and VO2peak of 43.5 ± 7.0 ml min-1 kg-1. Cerebral O2Hb increased to an intensity of 89.4 ± 5.5 %VO2peak, where a breakpoint occurred at which cerebral O2Hb started to decrease. Cerebral HHb increased slightly to 88.1 ± 4.8 %VO2peak, at which the increase was accelerated. Muscle HHb increased to 90.5 ± 4.8 %VO2peak where a leveling-off occurred. RCP occurred at 89.3 ± 4.3 %VO2peak. The breakpoints and RCP did not differ significantly (P = 0.13) and were strongly correlated (r > 0.70, P < 0.05). There were no differences between boys and girls (P = 0.43) and there was no significant correlation with VO2peak (P > 0.05). CONCLUSIONS: It was shown that cerebral and muscle oxygenation responses undergo significant changes as work rate increases and show breakpoints in the ongoing response at high intensity (85-95 %VO2peak). These breakpoints are strongly interrelated and associated with changes in pulmonary gas exchange.
AIMS: To characterize the oxygenation responses at cerebral and locomotor muscle level to incremental exercise in children and to assess the interrelationship with the pulmonary gas exchange responses. METHODS: Eighteen children (9 boys, 9 girls) (mean age 10.9 ± 1.0 years) performed incremental cycle ramp exercise to exhaustion. The concentration of cerebral and muscle oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin (by means of near-infrared spectroscopy) and pulmonary gas exchange was recorded. Cerebral and muscle O2Hb and HHb values were expressed as functions of oxygen uptake (VO2) and breakpoints were detected by means of double linear model analysis. The respiratory compensation point (RCP) was determined. The breakpoints in cerebral and muscle O2Hb and HHb were compared and correlated to RCP. RESULTS: The subjects reached peak power output of 105 ± 18 W and VO2peak of 43.5 ± 7.0 ml min-1 kg-1. Cerebral O2Hb increased to an intensity of 89.4 ± 5.5 %VO2peak, where a breakpoint occurred at which cerebral O2Hb started to decrease. Cerebral HHb increased slightly to 88.1 ± 4.8 %VO2peak, at which the increase was accelerated. Muscle HHb increased to 90.5 ± 4.8 %VO2peak where a leveling-off occurred. RCP occurred at 89.3 ± 4.3 %VO2peak. The breakpoints and RCP did not differ significantly (P = 0.13) and were strongly correlated (r > 0.70, P < 0.05). There were no differences between boys and girls (P = 0.43) and there was no significant correlation with VO2peak (P > 0.05). CONCLUSIONS: It was shown that cerebral and muscle oxygenation responses undergo significant changes as work rate increases and show breakpoints in the ongoing response at high intensity (85-95 %VO2peak). These breakpoints are strongly interrelated and associated with changes in pulmonary gas exchange.
Authors: Leonardo F Ferreira; Paul McDonough; Brad J Behnke; Timothy I Musch; David C Poole Journal: Respir Physiol Neurobiol Date: 2005-12-22 Impact factor: 1.931
Authors: Juan M Murias; Matthew D Spencer; Daniel A Keir; Donald H Paterson Journal: Am J Physiol Regul Integr Comp Physiol Date: 2013-03-20 Impact factor: 3.619
Authors: Kristof Vandekerckhove; Joseph Panzer; Ilse Coomans; Annelies Moerman; Katya De Groote; Hans De Wilde; Thierry Bové; Katrien François; Daniel De Wolf; Jan Boone Journal: Front Physiol Date: 2019-12-11 Impact factor: 4.566