Mental Rehearsal Studies

An experiment conducted by Roure et al on Autonomic Nervous System Responses Correlate with Mental Rehearsal in Volleyball Training, found six specific autonomic nervous systems responses that revealed a strong correlation with mental rehearsal, thereby improving sports performance (both pre- and post-test Volleyball). Roure suggested that metal imagery may help in the construction of schema which can be reproduced, without thinking, in actual practice (Roure, R., et al. (1998). Autonomic Nervous System Responses Correlat with Mental Rehearsal in Volleyball Training. Journal of Applied Physiology, 78(2), 99-108. )

Gaggioli et. al. conducted a study “investigating the benefits of combining mental and physical training in learning a complex motor skill in basketball (the lay-up shot).” “Results showed that mental practice condition improved coordination and movement accuracy, suggesting the potential effectiveness of this approach in training complex motor skills” Gaggioli, A. , Morganti, L. , Mondoni, M. & Antonietti, A. (2013). Benefits of Combined Mental and Physical Training in Learning a Complex Motor Skill in Basketball. Psychology, 4, 1-6.

Using mental rehearsal to prepare for officiating

Mental rehearsal activates a network of neural coded programs that activate physiological responses. Therefore, imagining something means you are actually strengthening the neural pathways required for that skill and the more likely you are to reproduce it again in the future. Also by mentally practising, you become more familiar with the actions required to perform a skill. These actions can become coded into symbols that make the actions more familiar or automatic.
https://secure.ausport.gov.au/sports_official/mental_preparation/using_mental_rehearsal_to_prepare_for_officiating

Mental Practice in Sports for Skill Development and Competition

Athletes can benefit from this technique in two ways.Internal imaging means that the athlete is approximating a real-life situation that he or she might expect in competition. External imaging means viewing themselves as the observer, as if watching a movie.
http://www.sports-training-adviser.com/mentalpractice.html