Imagery content and perspective and its effect on development of muscular strength
Equivocal results for imagery as a beneficial adjunct to performance may be due to diverse methodologies as well as a lack of clarity about the relationship between imagery ability and imagery perspective. This study used a randomized group design with repeated measures to evaluate the effect of imagery content and perspective on strength.
Subjects were 44 women, ages 19 to 34, classified as beginning weight lifters. All were pre-tested on imagery ability and knee joint strength. Subjects were randomly assigned to one of three training conditions: (1) an internal imagery perspective; (2) an external imagery perspective, and (3) no imagery training. Training was conducted twice per week for eight weeks. Subjects were also asked to work out a third time.
The dependent measure to assess strength at the beginning, middle, and end of the eight-weeks was the Cybex II dynamometer. The dependent measure to assess imagery vividness was the Betts questionnaire Upon Mental Imagery. Imagery perspective was measured by the Imagination Exercise.
Results of a two-way analysis of variance with repeated measures using Cybex II found significant strength differences for: (1) all groups and (2) the internal imagery group. A significant linear trend was also found between groups. Additionally, a two-way analysis of variance with repeated measures, using imagery ratings found significant improvement in kinesthetic vividness for all groups.
This investigation is the first experimental study using beginning athletes to demonstrate significant performance effects using mental training above and beyond significant effects due to physical training.