Blood Viscosity Responses to Exercise and Conditioning in Women
Abstract
Aerobic capacity is limited by the amount of oxygen delivered to the working muscles and the rate of utilization of oxygen at the tissue level. At a given arterial oxygen content the amount of oxygen delivered is a function of blood flow. Blood flow is in turn dependent upon vascular hindrance and blood viscosity. To assess whether aerobic conditioning might alter oxygen transport through changes in blood viscosity, several components of blood viscosity were measured in healthy women. Forty-seven women (fifteen sedentary women, 14 joggers who ran 5-15 miles per week and 18 marathoners who ran more than 50 miles per week) were evaluated. When evaluated by maximum exercise tolerance on the Bruce protocol, they had clearly different maximal aerobic capacities, 34.1 +/- 5.5, 44.8 +/- 4.4 and 51.0 +/- 5.2 ml kg-1 min-1, respectively, for the sedentary group, joggers and marathoners. There were no significant differences in resting whole blood viscosity, hematocrit, plasma viscosity, erythrocyte sedimentation rate, zeta sedimentation ratio or plasma protein concentration among the three conditioning groups. Immediately following exercise and after recovery all groups demonstrated similar changes in blood viscosity factors. Conditioning levels and aerobic capacities did not correlate with resting, exercise or recovery whole blood viscosity or its components. Whole blood viscosity increased with exercise in all subjects. The increase was greater than can be attributed to an increase in hematocrit. It appears to be due to a coincident increase in plasma protein concentration. However, the increase in whole blood viscosity after exercise was lower than expected given the observed hemoconcentration. This blunted response is attributable to a non-parallel increase in plasma proteins and hematocrit. Plasma protein concentration and, subsequently, plasma viscosity did not rise to the degree expected.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 20, 1983
- Accession Number
- AD1010654
Entities
People
- Dale G. Martin
Organizations
- Uniformed Services University of the Health Sciences