Purpose:
To determine the energy expenditure in dancers and the nature of energy transformations which take place during a simulated final round of sports dance competition in standard style.

Methods:
The study involved 6 sports dancing couples in highest dance classes (4 couples in S class, 2 couples in A class) according to WDSF (World Dance Sport Federation). There were two phases of the study. The first phase was to determine anthropometric indices, the second – to carry out a simulation of a tournament round in standard style. During a simulated final round of sports dance competition, heart rate (HR) and lactate concentration (La–) were measured, respiratory indicators were recorded (VO₂, VCO₂, RER), and energy expenditure was calculated.

Results:
The VO₂ values rated during each round differed statistically significantly between the group of men and women, (34.59 ± 3.82 ml • min^–1 • kg^–1 and 44.18 ± 4.34 ml • min^-1 • kg^–1; F = 41.07, p = 0.01). The mean respiratory exchange ratio was 1.08 ± 0.07 in men and 1.06 ± 0.07 in women. During a round, the lactate concentration increased, and at the end, after the last dance, it reached the value of 12.9 ± 2.1 mmol • l^–1 in women and 13,3 ± 2.7 mmol • l^–1 in men. The energy expenditure after the completed round in men was 16.6 ± 1.3 kcal • min^–1 and was higher than in the group of women, 10.7 ± 1.0 kcal • min^–1 (F = 3.67; p = 0.01). The highest energy expenditure in all subsequent dances was noted during quickstep.

Conclusions:
The study results complement the knowledge on the intensity of dance effort and confirm that the dance effort during sports competition is one of the heavy forms of physical activity based on aerobic and anaerobic energy processes. Therefore, the periodization of dance couple training process should considerably take into account the implementation of training loads that would help building solid aerobic and anaerobic capacity.