title: Hemorheological alterations related to training and overtraining.
abstract: Alterations of blood rheology related to muscular activity have been extensively studied over the last 20 years. It has been shown that exercise exerts a "triphasic" action on the rheological properties of blood. In the short term, exercise induces a transient hyperviscosity, mostly due to a rise in hematocrit and plasma viscosity, but also to alterations in erythrocyte rheology. Reversal of this hyperviscosity pattern over the following 24 h can be described as an "autohemodilution". Later, training results in several profiles of "hemorheologic fitness" with a low hematocrit reflecting an expansion in plasma volume, and improvements in red cell rheology (increased deformability, decreased aggregation, reduced disaggregation shear rate). Some specific aspects of these long-term adaptations have been described, such as the intriguing occurrence of a paradoxical improvement in RBC deformability during exercise in some athletes, and overtraining, which is associated with higher plasma viscosity. Given the variety of modes of exercise and the wide heterogeneity of their effects on blood rheology in the short and long term, many investigations remain to be performed in this area of clinical hemorheology.
authors.affiliation: Service Central de Physiologie Clinique, Unité d'Exploration Métabolique, CHU Lapeyronie, Montpellier, France. jean-frederic.brun@laposte.net
authors.forename: Jean-Frédéric
authors.initials: JF
authors.lastname: Brun
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Varlet-Marie
authors.forename: Philippe
authors.initials: P
authors.lastname: Connes
authors.forename: Ikram
authors.initials: I
authors.lastname: Aloulou
mesh_terms: D001809:Blood Viscosity; D004907:Erythrocyte Deformability / Q000502:physiology; D015444:Exercise; D018056:Hemorheology; D006801:Humans; D018384:Oxidative Stress