Original articles  BODY COMPOSITION, SPORT NUTRITION AND SUPPLEMENT (ERGOGENICS) 

The Journal of Sports Medicine and Physical Fitness 2004 March;44(1):44-8

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

Postexercise increase of free fatty acids. A qualitative indicator for free fatty acid utilisation during exercise?

Vobejda C. ¹, Simon G. ², Zimmermann E. ¹

¹ Sportmedizin, University Bielefeld, Bielefeld, Germany 2 Sportmedizin Institut, Sportschule der Bundeswehr Warendorf, Germany

Aim. The pur­pose of ­this ­study was to ­verify the hypoth­esis ­that the ­postexer­cise ­increase (PEI) of ­plasma ­free ­fatty ­acid (FFA) con­cen­tra­tions ­after ces­sa­tion of exer­cise is a suit­able qual­ita­tive indi­cator for the FFA util­isa­tion ­during the fore­going exer­cise.
­Methods. Four­teen, 17 and 23 ­healthy sub­jects par­tic­i­pated in 3 ­test ­series per­forming sev­eral pro­longed exer­cise pro­to­cols (PEP) on a ­bicycle ergom­eter. ­During and ­after ces­sa­tion of the PEP ­heart fre­quency, lac­tate and FFA ­were meas­ured.
­Results. ­Fasting ­resulted in an ­increase of PEI (90%, p<0.05) and the syn­er­gistic use of ­upper ­body mus­cles ­during ­cycling ­caused a sig­nif­i­cant ­rise of PEI com­pared to “reg­ular” ­cycling (39%, p<0.01). ­Increasing work­load ­step by ­step pro­duced con­tin­u­ously ­rising PEI (p<0.05), ­only ­from 42% to 50% of max­imal work­load PEI ­decreased by 17% (p=n.s.).
Con­clu­sion. The ­results sup­port the hypoth­esis ­that PEI is a suit­able qual­ita­tive indi­cator for FFA util­isa­tion ­during a fore­going exer­cise. Fur­ther­more the ­results indi­cate ­that ­there is a max­imum of FFA util­isa­tion in the ­legs at 40% of max­imum work­load ­during ­cycling and ­that the ­upper ­body mus­cles con­tribute sub­stan­tially to ­total ­body FFA turn­over at ­high ­inten-­sities, an ­aspect to ­which pos­sibly too ­little atten­tion has ­been ­paid to ­when quan­ti­fying FFA turn­over ­during ­cycling.