Purpose:
The aim was to investigate the effects of verbal feedback on biomechanical performance variables during swimming ergometry.

Methods:
The total of 100 healthy and physically active males (19.56 ± 1.32 years of age, 181.23 ± 4.35 cm in height, and 70.54 ± 8.6 kg in weight) participated in the study. The subjects were randomized into 2 groups (experimental and control); 2 sessions were administered. In the first session (pre-test), both groups completed the butterfly stroke on a swimming ergometer in identical conditions. In the second session (post-test), the experimental group received verbal instructions that conveyed kinaesthetic information. To rationalize verbal information, the criteria of efficient didactic communication were applied (syntax, semantics, and pragmatics). Biomechanical performance was monitored continuously by measuring work output (J), total force (N), power output (W), and total distance of hand travel (cm).

Results:
Differences in the average values of the analysed variables between groups and samples were determined with a multivariate analysis of variance (MANOVA) (p < 0.05). The analysis of the results showed that the inclusion of verbal feedback resulted in statistically significant increases between pre- and post-test in all biomechanical variables in the experimental group, as well as in significant between-group differences post-test.

Conclusions:
Appropriately prepared verbal cues following the criteria of efficient didactic communication may improve biomechanical performance during movement execution on a swimming ergometer.