BIOLOGICAL SECTION   

Medicina dello Sport 1999 June;52(2):105-17

Copyright © 1999 EDIZIONI MINERVA MEDICA

language: English

Urinary and serum electrolyte changes in athletes during periodic and continuous restriction of muscular activity

Zorbas Y. G., Kakurin V. J., Denogratov S. D., Yarullin V. L.

Kosmic Biology and Medicine Institute, Krasno Selo, Sophia, Bulgaria

It was ­assumed ­that peri­od­ic hypo­ki­ne­sia (PHK) induc­es ­much great­er bio­chem­i­cal chang­es ­than con­tin­u­ous hypo­ki­ne­sia (CHK). Thus, the aim of ­this ­study was to meas­ure uri­nary and serum elec­tro­lyte chang­es dur­ing PHK and CHK in endu­rance ­trained ath­letes.
Studies ­were done dur­ing 30 ­days peri­od of pre-hypo­ki­ne­sia (PHK) and dur­ing 364 ­days of PHK and CHK peri­ods. Thirty male ath­letes ­aged 22 to 26 ­years ­were cho­sen as sub­jects. They ­were equal­ly divid­ed ­into ­three ­groups: unre­strict­ed ambu­la­to­ry con­trol sub­jects (­UACS), con­tin­u­ous­ly restrict­ed hypo­ki­net­ic sub­jects (­CHKS) and peri­od­i­cal­ly restrict­ed hypo­ki­net­ic sub­jects (­PHKS).
The ­CHKS ­group was main­tained ­under an aver­age run­ning dis­tance of 1.7 km·day-1 for 364 ­days, ­while the ­PHKS ­group was main­tained ­under an aver­age run­ning dis­tance of 1.7 and 11.7 km·­day-1 for ­five ­days and two ­days per ­week, respec­tive­ly, for 364 ­days. The ­UACS ­group was main­tained ­under an aver­age run­ning dis­tance of 11.7 km·day-1, ­that is, ­they ­were expe­ri­enced no chang­es in ­their pro­fes­sion­al train­ing and rou­tine dai­ly activ­ities.
During the pre HK peri­od and the peri­ods of CHK and PHK uri­nary and ser­um mag­ne­sium (Mg) cal­cium (Ca), sodi­um (Na) and potas­sium (K) ­were meas­ured. Plasma aldos­te­rone (PA) and plas­ma ­renin activ­ity (PRA), ser­um para­thy­roid hor­mone (PTH) and cal­cit­o­nin (CT) was ­also meas­ured. In the ­PHKS and ­CHKS ­groups uri­nary elec­tro­lyte excre­tion, and ser­um elec­tro­lyte con­cen­tra­tions ­increased sig­nif­i­cant­ly (p≤0.01) ­when com­pared ­with the ­UACS ­group. PRA and PA con­cen­tra­tion ­increased sig­nif­i­cant­ly (p≤0.01), ­while ser­um PTH and CT con­cen­tra­tion ­decreased sig­nif­i­cant­ly (p≤0.01) in the hypo­ki­net­ic sub­jects ­when com­pared ­with the con­trol sub­jects. In the ­PHKS ­group the chang­es in the meas­ured param­e­ters ­were ­much great­er and ­occurred fast­er ­than in the ­CHKS ­group; how­ev­er, no sig­nif­i­cant dif­fer­enc­es ­observed ­between the ­PHKS and ­CHKS ­groups regard­ing meas­ured param­e­ters. The ­UACS ­group did not ­show any sig­nif­i­cant chang­es regard­ing the cor­re­spond­ing param­e­ters ­when com­pared ­with the base­line con­trol val­ues.
It was con­clud­ed ­that ­both PHK and CHK ­induced sig­nif­i­cant uri­nary and ser­um elec­tro­lyte chang­es in ­trained ath­letes; how­ev­er, uri­nary and ser­um elec­tro­lyte chang­es ­were ­much great­er and ­much fast­er in ­PHKS ­group ­than in the ­CHKS ­group.