Does endurance training improve red blood cell aging and hemorheology in moderate-trained healthy individuals?

ObjectiveTo examine the impact of a 6-week endurance training on red blood cell (RBC) aging and deformability of healthy participants to detect possible improved hemorheological and performance-related adaptations.MethodsA total of 31 participants (17 females and 14 males) performed a 6-week moderate training protocol (three 1-h running sessions per week at 70% of maximal heart rate). Blood was sampled before and after the training. RBCs from each participant were fractioned according to density and age into 4 RBC subfractions. Subfractions were examined for changes of RBC properties, including aging distribution, RBC deformability, RBC microparticles, and phosphatidylserine concentrations. RBC and plasma nitrite levels were measured as indicators of nitric oxide metabolism.ResultsAerobic performance, peak oxygen consumption, ventilatory thresholds, velocity at the aerobic–anaerobic threshold, and lactate at exhaustion improved after training. The relative amount of both young RBCs and old RBCs increased, and the amount of the main RBC fraction decreased. Phosphatidylserine externalization and RBC-derived microparticles decreased. Overall deformability expressed as shear stress required to achieve half-maximum deformation to theoretical maximal elongation index at infinite shear stress improved in unfractioned RBCs (p < 0.001). Nitrite decreased in total (p = 0.001), young (p < 0.001), main (p < 0.001), and old (p = 0.020) aged RBCs and in plasma (p = 0.002), but not in very old RBCs.ConclusionThese results indicate that non-endurance-trained healthy participants benefit from a regular moderate running training program because performance-related parameters improve and a younger RBC population with improved RBC properties is induced, which might support oxygen supply in the microcirculation.     

Not exotic,but too familiar…

ABSTRACT

Urbanization over in last three decades in China has produced and accumulated more and more complex problems and challenges in everyday life. People need different spaces and ways to learn about them, not only to understand what kind of problems they face, but also find a way to act together in order to change their passive situation and take part in the process which always seem to be dominated by government and technology. “Womende Chengshi” (Our Cities) citizen forum was built in 2012 and has lasted for almost 5 years in Shanghai. It aims to create a new educational space for citizens to discuss emerging city problems and to imagine alternative ways of urban life. After a concise introduction about this forum in Chinese social context, this paper will focus on three points. First, while the ideal setting suggests that citizens are everyone living in the city, “Our Cities” actually confronts the concrete ones shaped by various spaces and limited times in the whole city system. So how to struggle with different forces in limited time and space in everyday life is the main duty this forum needs to face. The third point follows: what kind of standard we could have to estimate such self-education process?