Review articles   

The Journal of Sports Medicine and Physical Fitness 2000 March;40(1):80-4

Copyright © 2002 EDIZIONI MINERVA MEDICA

lingua: Inglese

Markers of hydration status

Shirreffs S. M.

From Biomedical Sciences University Medical School Foresterhill, Aberdeen, Scotland

This ­paper ­reviews the lit­er­a­ture, ­describes and dis­cus­sess meth­ods by ­which ­whole ­body hydra­tion stat­us can be deter­mined in ­humans. A meth­od of deter­min­ing wheth­er or not an indi­vid­u­al is hypo­hy­drat­ed is of par­tic­u­lar sig­nif­i­cance in an exer­cise sit­u­a­tion as ­even mod­er­ate lev­els of hypo­hy­dra­tion ­have a neg­a­tive ­impact on exer­cise per­for­mance. Inspection of the pub­lished lit­er­a­ture indi­cates ­that a num­ber of meth­ods ­have ­been ­used to deter­mine hydra­tion stat­us. Body ­mass chang­es, uri­nary indi­ces (vol­ume, ­colour, pro­tein con­tent, spe­cif­ic grav­ity and osmo­lal­ity), ­blood ­borne indi­ces (hae­mog­lo­bin con­cen­tra­tion, hae­ma­toc­rit, plas­ma osmo­lal­ity and sodi­um con­cen­tra­tion, plas­ma tes­tos­te­rone, adren­a­line, nor­a­dren­a­line, cor­ti­sol and atri­al nat­iu­ret­ic pep­tide), bio­electri­cal impe­dance anal­y­sis, and ­pulse ­rate and sys­tol­ic ­blood pres­sure ­response to pos­tu­ral ­change are dis­cussed. The uri­nary meas­ures of ­colour, spe­cif­ic grav­ity and osmo­lal­ity are ­more sen­si­tive at indi­cat­ing mod­er­ate lev­els of hypo­hy­dra­tion ­than are ­blood meas­ure­ments of hea­ma­toc­rit and ser­um osmo­lal­ity and sodi­um con­cen­tra­tion. Currently no “­gold stan­dard” hydra­tion stat­us mark­er ­exists, par­tic­u­lar­ly for the rel­a­tive­ly mod­er­ate lev­els of hypo­hy­dra­tion ­that fre­quent­ly ­occur in an exer­cise sit­u­a­tion. The ­choice of mark­er for any par­tic­u­lar sit­u­a­tion ­will be influ­enc­ed by the sen­si­tiv­ity and accu­ra­cy ­with ­which hydra­tion stat­us ­needs to be estab­lished togeth­er ­with the tech­ni­cal and ­time require­ments and ­expense ­involved.