title: The need and benefit of augmented feedback on service speed in tennis.
abstract: OBJECTIVE
  Accurate knowledge of results (KR), in the form of service speed, is important in learning to serve faster. The aim was to determine whether players could accurately judge if their serve was faster or slower than their preceding serve (experiment 1) and if providing them with accurate augmented KR feedback on service speed using a speed gun could enhance learning after training (experiment 2).
  
  
  METHODS
  In experiment 1, 11 high-level national junior players served 10 serves to a target area and were asked to judge whether the serve was faster/slower that the preceding serve. In experiment 2, 12 high-level national junior players, divided into two groups, trained to improve their service speed for 12 wk (three sessions per week). During the first 6 wk (90 maximum-effort serves/session), they received either augmented (group 1) or no augmented (group 2) KR feedback. During the following 6 wk, participants did not complete the 90 serves per session and received no augmented KR feedback (retention test).
  
  
  RESULTS
  In experiment 1, players could not correctly determine whether serves were faster/slower than the preceding serve. In experiment 2, both groups significantly enhanced their service speed after the initial 6 wk of service training, but the enhancement was significantly greater (P = 0.01) in the augmented versus no augmented KR feedback group (0.84 ± 0.38 vs 0.22 ± 0.04 m·s⁻¹ ). These enhancements were still evident during the retention test (P = 0.01).
  
  
  CONCLUSIONS
  Players cannot accurately judge service speed, and by providing this information in the form of augmented feedback, a player can enhance the process of learning to serve faster with training. Players should therefore use augmented feedback on service speed when training to serve faster.
authors.affiliation: School of Health and Human Performance, Dublin City University, Dublin, Ireland. kieran.moran@dcu.ie
authors.forename: Kieran Andrew
authors.initials: KA
authors.lastname: Moran
authors.forename: Colm
authors.initials: C
authors.lastname: Murphy
authors.forename: Brendan
authors.initials: B
authors.lastname: Marshall
mesh_terms: D000293:Adolescent; D054874:Athletic Performance / Q000502:physiology / Q000523:psychology; D005246:Feedback; D005260:Female; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology; D013715:Tennis / Q000502:physiology* / Q000523:psychology