Relationship between training status and maximal fat oxidation rate

This study aimed to compare maximal fat oxidation rate parame-ters between moderate- and low-performance runners. eighteen runners performed an incremental treadmill test to estimate individual maximal fat oxidation rate (fatmax) based on gases measures and a 10,000-m run on a track. the subjects were then divided into a low and moderate performance group using two different criteria: 10,000-m time and vo2max values. when groups were divided using 10,000-m time,there was no signifi-cant difference in fatmax (0.41 ± 0.16 and 0.27 ± 0.12 g.min-1,p = 0.07) or in the exercise intensity that elicited fatmax (59.9 ± 16.5 and 68.7 ± 10.3% o2max,p = 0.23) between the moder-ate and low performance groups,respectively (p > 0.05). when groups were divided using vo2max values,fatmax was signifi-cantly lower in the low vo2max group than in the high vo2max group (0.29 ± 0.10 and 0.47 ± 0.17 g.min-1,respectively,p < 0.05) but the intensity that elicited fatmax did not differ between groups (64.4 ± 14.9 and 61.6 ± 15.4%vo2max). fatmax or %vo2max that elicited fatmax was not associated with 10,000 m time. the only variable associated with 10,000-m running per-formance was %vo2max used during the run (p < 0.01). in conclusion,the criteria used for the division of groups according to training status might influence the identification of differences in fatmax or in the intensity that elicits fatmax. © journal of sports science and medicine.