Background: The bench press (BP) is a complex exercise of the upper body in which great external loads requiring high neuromuscular activity can be lifted. Electromyography (EMG) is a study of the muscle function through the inquiry of the electrical signal the muscles emanate. The aim of the present study was to analyse changes in EMG activity of the prime movers during 10 sets of the flat bench press. Material and methods: Ten male athletes representing different sport disciplines, experienced in resistance training took part in the study. Results: In the first set, all of the tested muscles increased their tension from the first 3 repetitions to the last 3 repetitions. The tension of these muscles increased in successive repetitions and reached significantly greater values in the last repetitions of the set. In the 10th final set of the BP exercise protocol the athletes performed only 8-9 repetitions, and the activity of all studied muscles decreased significantly from the first 3 to the last 3 repetitions of the set. Conclusions: It seems that peripheral fatigue limits the number of repetitions in the first set of the BP, while central fatigue accumulates with each set, causing a very significant drop in EMG activity and the load lifted in the 10th, last set of the exercise protocol.