Rest Energy Expenditure and Energy Expenditure During Submaximal Exercise: New Approach to Assessment of Performance in Skiers

Abstract

The aim of the present study was to analyse rest energy expenditure (REE) and energy expenditure (EE) during submaximal exercise according to performance of athletes. A retrospective analysis of data from 2014 to 2020 among cross-country skiers in the preparatory phase was performed. Depending on the potential performance athletes (n = 136) were divided into two groups: I – test completed to the anaerobic threshold (AnT), II – test completed until exhaustion. The present study included the data only before AnT for a correct comparison of the results. REE was 2058.5 ± 220.5 kcal/day in I group and 2023.1 ± 216.4 kcal/day in II group (p = 0.481). In REE structure, the contribution of fats and carbohydrates (CHOs) was 69 and 31% in I group, 48 (p = 0.021) and 52% (p 0.000) in II group. Correlations between VO2rest and REE, as well as the rate of fats and CHOs oxidation at rest were revealed. In I and II groups the VO2AnT (p 0.000) and relative values of VO2max (p 0.05) were significantly different. EE before AnT was 135.9 ± 31.2 and 134.0 ± 23.4 kcal (p = 0.399) for I and II groups. The present study showed that the balance 1 : 1 of fats and CHOs in the REE structure is a more informative performance marker than quantitative assessment of EE. VO2AnT reduced by 20% relative to VO2max may indicate the functional economization and the body’s ability to perform exercise during long time, including in the anaerobic exercise. Endurance athletes demonstrated economy of CHOs against actively using of fats during submaximal exercise. Complex estimated of performance indicators and EE (including contribution fats and CHOs) should be taken into account when studying the performance of athletes.