Abstract
Three substudies were conducted to determine the effects of mental practice on improvement in serving and volleying skills in volleyball. The first substudy (10 subjects) compared mental practice (3 min. daily for each skill for 2 weeks) with no practice. The other substudies compared 3 min. and 1 min. of daily mental practice on each skill in addition to equal time for physical practice. The experimental periods were for 5 weeks (68 subjects) and 3 weeks (36 subjects). No statistically significant results were obtained for the volleying skill; however, the first two studies yielded significant results for the serving skill. Mental practice produced better results (P < .025) than did no practice, and 3 min. of mental practice was superior (P < .05) to 1 min. In conjunction with the last substudy, two additional areas were investigated. A questionnaire was administered concerning the mental practice periods, and electromyographic records were obtained from 19 subjects to investigate intrinsic muscular involvement. Subjects tended to report that they “felt the action” and had “clear” or “mostly clear” images during mental practice periods. Varying amounts of muscular involvement were evidenced in the electromyograms. No one single variable, of those considered in this investigation, could be said to be the key factor in determining a given individual's improvement score.