Impact of Reduced Net Height and Ball Speed Feedback on Spiking Ability in Introductory Volleyball

The aim of the study was to explore the impact of an intervention based on the manipulation of the margin of error and the provision of ball speed feedback on the ability to spike in introductory volleyball. To this end, an exploratory study without a control group was conducted. The sample consisted of two U-14 volleyball teams, one male team with 14 players (13.2 ± 0.75 years), and one female team with 12 players (14 ± 0 years). The intervention involved reducing the height of the net, providing immediate feedback on the speed of the ball after the spike, and challenging the target zone of the spike. It was applied across 12 sessions, with eight spikes per player per session. The study variables recorded in each spiking were ball speed (which was measured using the Pocket Radar Ball Coach instrument), jump height (which was measured using the VERT Wearable Jump Monitor), and target area for sending the ball (which was filmed using a high-speed video camera). The players' perception of the intervention was also assessed. The most significant results indicated that the achievement of the impact in the more restricted target area of the spiking, compared to the larger target area, led to a significant increase in jumping, both in men and women. As maintaining spike ball speed was necessary to validate the challenge, speed values did not decrease when hitting toward the restricted zone. In fact, for male players, there was an unexpected significant increase in spike ball speed. The initial speed was the variable that best predicted the maximum speed acquired throughout the treatment. Reducing the net height while restricting the spiking area can have a positive impact on spike kinematics, provided that spike velocity is maintained.