[Accordance of energy intake to energy expenditure in skiers across the preparation phase]

In elite sport the amount of physical activity requires a professional athlete to have a stable energy balance when the energy intake (EI) is equal to energy expenditure (EE). Its maintenance provides high performance across the phases of the training cycle. The purpose of this research was to analyze the compliance of EI to EE among skiers during the preparation phase of the training cycle. Material and methods. The single-centre, prospective, longitudinal, full-design, noncontrolled study has been performed on 55 highly trained cross-country skiers (mean age 20.1±4.7 years) during the preparation phase of the training cycle. EI was estimated by a 24-hour dietary recall. EE was estimated at rest and during physical activity by indirect calorimetry using the Oxycon Pro system. Results. During the preparation phase dietary calorie intake in skiers (3191±961 kcal/ day), estimated excluding sports drink consumption during the training, was lower approximately by 40% than the reference norms for people engaged in intensive physical activity. At the same time, there was 1.3-fold excess of fats in the diet against the background of low consumption of carbohydrates. Our results showed that in 75% of athletes the measured rest energy expenditure (REE) was higher than the calculated REE by 20% and amounted to 2139±363 kcal/day. Total EE during the preparation phase, calculated by application of Physical Activity Level (PAL) coefficient equal 2.4 (according FAO/ WHO/UNU recommendations), was 5137±873 kcal/day (73.9±12.3 kcal/kg per day). In most cases registered total EE was more than 5000 kcal/day, in other words, total EE exceeded the energy value of the daily diet and thus required the increase of EI. In addition, in our study we observed an increase of carbohydrate contribution to the total EE during high-intensity exercise. Conclusion. The discrepancy between dietary calories and daily EE among the elite athletes was revealed. An imbalance between carbohydrates and fats was identified in the diet, and that did not provide the optimal expenses of macronutrients during highintensity exercise.