Muscular development motives for exercise participation: the missing variable in current questionnaire analysis?

Motivation questionnaires that are currently validated do not account for muscular development motives in exercise populations, and have rarely been used to examine resistance training populations. Resistance training is a popular and widely available exercise, so the lack of such motivational information is a cause for concern. The aim of this study was to assess the need for considering motives for muscular development. This was achieved by the development of a simple scale that matched the format and style of the Exercise Motivations Inventory. The muscular development scale was combined with the 'weight management' and 'appearance' items of the Exercise Motivations Inventory to form a 13-item test questionnaire. This was administered to four groups of experienced exercisers: resistance training males (n = 40), resistance training females (n = 36), males training in a variety of sports (n = 27) and aerobic training females (n = 40). Factor analysis with varimax rotation revealed a relatively distinct muscular development factor, but with cross-loading on weight management. Muscular development was shown to be the most effective discriminator for the four groups. A multivariate analysis of variance and additional discriminant analysis revealed a series of significant differences between groups, which suggests that motive-based differences are more powerful than sex factors in determining choice of exercise modality. Although the interrelated nature of muscular development and weight management needs to be recognized and accounted for, there is a clear need for considering muscular development motives in future investigations, especially those that intend to examine motives for 'ideal' physical appearance.