The fat oxidation rate at rest and under exercise load «until exhaustion» in Nordic skiers

Objective: to study the fat oxidation rate during physical exercises of different intensity and to identify factors influencing this process in athletes. Materials and methods: highly qualified Nordic skiers (26 men, 11 women) were examined. Fat oxidation (FO) was determined by the indirect colorimetric technique within stepwise increasing cycle load in the test «to failure». Results: FO for highly skilled skiers (MS and MSIL) was 0.17 g/min at rest and 0.77 g/min at the peak of the load, corresponding to the range of 40-60% of the maximal oxygen consumption (MOC). The level of skill was associated with a higher peak FO and its longer retention up to a load of 80-90% of the MOC. Age differences appeared only at the peak of the load, in the range of 60-70% of the MOC. There was a higher base and maximum FO in men, unlike women. Conclusions: the fat oxidation rate during exercise should be used in assessing the functional state of athletes when planning load regimes and preventing overtraining.