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RESEARCH PRODUCT

Hemoconcentration induced by exercise: Revisiting the Dill and Costill equation

subject

description

The Dill and Costill equation is used to estimate the exercise-induced hemoconcentration. However, this cal- culation requires drawing an extra whole-blood sample, which cannot be frozen and has to be analyzed with dedi- cate instrumentation in a relative short time. The aim of the present study was to explore the usefulness of some serum biochemical parameters to estimate hemoconcen- tration induced by exhaustive exercise. Fourteen healthy male subjects (19-34 years) performed a15-min running test at 110% of anaerobic threshold speed. Hemoglobin, hematocrit, brain natriuretic peptide (BNP), creatinine, gamma-glutamyltransferase (GGT), total-proteins, albu- min, total calcium (Ca), K + ,N a + , and Cl − were determined in blood samples taken before, after exercise, and after a 30-min recovery period. Plasma volume loss (ΔPV) was calculated by Dill and Costill equation. At post-exercise and after recovery, the percentage increments of total-proteins, albumin, GGT and Ca correlated signifi- cantly with ΔPV. Bland-Altman analyses showed that correcting BNP, creatinine, and K + concentration by Ca percentage increments yield biases and limits of agree- ment that are acceptable when compared with Dill and Costill equation correction. Ca concentration may be used as a hemoconcentration biomarker in high-intensity exercise, which would allow scientists and physicians avoid extra costs, facilitate in-field research, and delayed estimation of hemoconcentration using stored serum samples.