Michail E. Keramidas

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Recent findings suggest that besides renal tissue hypoxia, relative decrements in tissue oxygenation, using a transition of the breathing mixture from hyperoxic to normoxic, can also stimulate erythropoietin (EPO) production. To further clarify the importance of the relative change in tissue oxygenation on plasma EPO concentration [EPO], we investigated the(More)
The purpose of the study was to investigate the effect of 30-min voluntary hyperpnoea on cerebral, respiratory and leg muscle balance between O(2) delivery and utilization during a subsequent constant-power test. Eight males performed a V˙O(2max) test, and two exercise tests at 85% of peak power output: (a) a control constant-power test (CPT), and (b) a(More)
The post-exercise emotional response is mainly dependent on the intensity of the exercise performed; moderate exercise causes positive feelings, whereas maximal exercise may prompt negative affects. Acute hypoxia impairs peak O2 uptake (V̇O2peak), resulting in a shift to a lower absolute intensity at the point of exhaustion. Hence, the purpose of the study(More)
The study examined the distinct and synergistic effects of hypoxia and bed rest on the erythropoietin (EPO) concentration and relative changes in plasma volume (PV). Eleven healthy male lowlanders underwent three 21-day confinement periods, in a counterbalanced order: (1) normoxic bed rest (NBR; PIO2: 133.1 ± 0.3 mmHg); (2) hypoxic bed rest (HBR; PIO2: 90.0(More)
To assess the effect of normobaric hypoxia on metabolism, gut hormones, and body composition, 11 normal weight, aerobically trained (O2peak: 60.6 ± 9.5 ml·kg(-1)·min(-1)) men (73.0 ± 7.7 kg; 23.7 ± 4.0 years, BMI 22.2 ± 2.4 kg·m(-2)) were confined to a normobaric (altitude ≃ 940 m) normoxic (NORMOXIA; PIO2 ≃ 133.2 mmHg) or normobaric hypoxic (HYPOXIA; PIO(More)
Supra-tolerance head-to-foot directed gravitoinertial load (+Gz) typically induces a sequence of symptoms/signs, including loss of: peripheral vision—central vision—consciousness. The risk of unconsciousness is greater when anti-G-garment failure occurs after prolonged rather than brief exposures, presumably because, in the former condition, mental signs(More)
The purpose was to investigate the effects of acute normobaric hyperoxia at rest on cerebral, respiratory and leg muscle oxygenation. Ten healthy men were studied twice in a single-blinded counterbalanced crossover study protocol. On one occasion they breathed air and on the other 100% normobaric O(2) for a 2-hour time period. Oxygenated (Δ[O(2)Hb]),(More)
The " normobaric oxygen paradox " originates from the ser-endipitous Wnding of a marked increase in the endogenous erythropoietin concentration 24 and 36 h after the cessation of a single 2-h intervention of normobaric oxygen breathing ; Balestra et al. (2006) suggested that a " relative hypoxic stimulus " , such as the transition from a high to a normal(More)
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