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


CONCLUSIONS
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.
Vobejda
C
C
Sportmedizin, University Bielefeld, Bielefeld, Germany. christian.vobejda@uni-bielefeld.de
Simon
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G
Zimmermann
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E
D000328:Adult; D001642:Bicycling / Q000502:physiology*; D005080:Exercise Test; D005215:Fasting / Q000502:physiology; D005230:Fatty Acids, Nonesterified / Q000097:blood* / Q000378:metabolism; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D013997:Time Factors; D034941:Upper Extremity / Q000502:physiology
D005230:Fatty Acids, Nonesterified