Original articles  BIOCHEMISTRY 

The Journal of Sports Medicine and Physical Fitness 2004 March;44(1):104-9

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

Plasma leptin responses to prolonged sculling in female rowers

Jürimäe J., Jürimäe T.

Sport Pedagogy Unit University of Tartu, Tartu, Estonia

Aim. ­Plasma ­leptin con­cen­tra­tions are ­reduced in the pres­ence of a neg­a­tive ­energy bal­ance. The pur­pose of ­this ­study was to inves­ti­gate the ­effects of a pro­longed ­single endu­rance ­rowing ­training ses­sion on ­plasma ­leptin con­cen­tra­tions in ­female ­rowers.
­Methods. Ten ­female col­lege ­level ­single ­scull ­rowers par­ti­cipa-ted in ­this ­study. ­Venous ­blood sam­ples ­were ­obtained ­during the ­early fol­lic­ular ­phase of the men­strual ­cycle imme­di­ately ­before and ­after on-­water ­rowing ­lasting ­about 2 h (7518±293 s; dis­tance cov­ered 18.9±1.4 km; ­heart ­rate 150±7 ­beats . min-1).
­Results. ­Blood lac­tate con­cen­tra­tion did not ­change sig­nif­i­cantly ­during ­sculling ­training ses­sion (­from 1.6±0.4 to 1.9±0.5 ­mmol . l-1) indi­cating ­that ­training was per­formed at mod­erate inten­sities. ­Leptin ­values ­were sig­nif­i­cantly ­reduced imme­di­ately ­after pro­longed ­rowing by a ­mean 44% and no fur­ther ­changes ­occurred ­during the ­first 2 h of ­recovery. ­Insulin and glu­cose ­values ­were ­also ­decreased imme­di­ately ­after pro­longed ­rowing. A fur­ther reduc­tion in ­insulin was ­seen ­during the 2nd ­hour of ­recovery. No fur­ther ­changes ­occurred ­during the ­first 2 h of ­recovery in glu­cose con­cen­tra­tion. ­Plasma ­leptin con­cen­tra­tions imme­di­ately ­after (r=-0.64), and 30 min (r=-0.66) and 2 h (r=-0.64) ­after an endu­rance ­rowing ­training ses­sion ­were ­related (p<0.05) to the dis­tance cov­ered. No ­such rela­tion was ­observed for ­other meas­ured ­blood bio­chem­ical param­e­ters. ­Leptin ­also cor­re­lated ­with ­insulin meas­ured at dif­ferent ­time ­points ­after endu­rance ­training (r>0.64; p<0.05). Regres­sion anal­yses dem­on­strated a pos­i­tive rela­tion­ship ­between ­total ­body fat ­mass and ­plasma ­leptin (R2>0.70; p<0.001) regard­less of sam­pling ­time in ­female ­rowers.
Con­clu­sion. Our find­ings indi­cate ­that a pro­longed low-inten­sity ­rowing ­training ses­sion ­results in an ­energy def­icit ­beyond the ­threshold ­that is nec­es­sary to ­reduce ­plasma ­leptin con­cen­tra­tion ­without ­changing ­body fat ­mass in ­female ­rowers. It was sug­gested ­that ­plasma ­leptin ­could be ­regarded as a ­signal for meta­bolic reac­tion to endu­rance ­rowing ­training ses­sion and fol­lowing ­recovery in ­female endu­rance ath­letes.