The aim of the study was to compare energy expenditure during three amateur athletes trainings, ie. volleyball, badminton and karate. The study was conducted among 36 adults (23 men and 13 women), aged 39 ±8. Polar M400 heart rate monitors with H7 chest strap were used to estimate energy expenditure during selected training sessions. Energy expenditure during badminton (1261 kcal; 631 kcal/h) and karate (1239 kcal; 823 kcal/h) trainings were significantly higher than energy expenditure during volleyball training (868 kcal; 579 kcal/h). Due to the large energy expenditure during single training session, it seems justified to assess both energy expenditure and energy intake among athletes.