Annals of Applied Sport Science

The goal of this study is searching effective time (before, during and after physical practice) for mental practice in learning the Volleyball Service Skill. Forty-five beginner students, aged 12–14 years, with no history of Volleyball Service Skill participated in the study (45 Male ones). Most of them were Secondary school students. All were unable to serve Volleyball correctly. The subjects were divided into the three groups (MP before PP, MP during PP and MP after PP). All subjects performed mental and physical practice in 21 sessions and for 30 minutes per session. The subjects were tested at the end of the 7^th, 14^th, 21^th, and 28^th sessions. The Volleyball Serving Test was used for test comparing the rate of learning. The result of this research showed there was significant difference between means of the MP-during-PP group, and the MP-before-PP and the MP-after-PP groups in improving their Volleyball Service skill. Moreover, the MP-before-PP and MP-after-PP groups did not differ from each other concerning the scores. The retention test showed that subjects in the MP-before-PP and the MP-after-PP groups, in contrast to the MP-during-PP group, did not significantly improve their Volleyball Service skill. This study suggested that coaches and P.E teachers apply mental practice (10 minutes) as an essential part in programs and teach the beginners that use mental practice in every time of physical practice (spatially during physical practice).

Age may limit the effect of contextual interference, but the accurate effect of age on contextual interference is not completely identified. Therefore, the purpose of the study was the effect of contextual interference practice orders on acquisition and learning of badminton skills of 45 female students aged from 10 to 12. Participants were randomly assigned to one of the three groups of blocked, random, and systematically increasing contextual interference. They trained three skills of badminton long serves, short serves, and forehand strokes for 10 sessions after pre-test. The tests consist of Acquisition, immediate retention, and delayed retention were taken after the fifth session, one hour after the end of the tenth session, and 48 hours after the last practice session, respectively. According to the findings of the study, in acquisition test, the blocked group achieved better scores than the random and systematically increasing groups. Although the three groups performed significantly better than pre-test scores in retention test, there was no difference among groups, meaning that contextual interference did not have positive results for children in learning badminton skills. Seemingly, due to the limitations in strategy, our participants were probably confused among the abundant information from the random practices and were not able to use the advantages of contextual interference. So, the benefits of random practice based on forgetting and elaborating hypotheses in this age group, especially regarding discrete motor skill in badminton is in doubt. The authors carefully suggest that elementary school physical education teachers should use blocked practice methods for badminton practice to help children build a suitable motor skills scheme and encourage them to repeat the desired skills because of the motivational feedback of blocked practice as a result of greater success in practice sessions.