Unique risk factors for the development of muscle dissatisfaction and engagement in muscle-building behaviors have been described by theoretical frameworks and supported by empirical research. What remains unknown are the unique processes, including catalysts and facilitators, which underpin engagement in muscle-building behaviors. Therefore, this study used a grounded theory methodology to elucidate the process of engagement in muscle-building behaviors. Thirty-three individual semi-structured interviews with Canadian adolescents and young adults ages 16–30 years were conducted. Transcripts were analyzed using initial and focused coding to identify themes that explained the grounded theory. The core theme underpinning the grounded theory was balancing aesthetic, health, and functional goals in relation to participants’ engagement in muscle-building behaviors. Participants described experiences that encompassed several unique phases of muscle-building engagement, including the initiation phase, beginner phase, preservation phase, and intensification phase. Participants also described unique methods of gathering information on muscle-building behaviors, and their own analysis and decision-making processes driving their behaviors. Findings from this study extend prior theory and research by conceptualizing a novel process theory of engagement in muscle-building behaviors among adolescent and young adults, resulting in important implications for research and practice.

理论框架描述了肌肉不满意和参与增肌行为的独特风险因素，并得到实证研究的支持。目前尚不清楚的是支撑肌肉锻炼行为的独特过程，包括催化剂和促进剂。因此，本研究使用扎根理论方法来阐明参与肌肉锻炼行为的过程。对 16 至 30 岁的加拿大青少年和年轻人进行了 33 次单独的半结构化访谈。使用初始和重点编码对成绩单进行分析，以确定解释扎根理论的主题。支撑扎根理论的核心主题是平衡与参与者参与肌肉锻炼行为相关的美学、健康和功能目标。参与者描述了涵盖肌肉锻炼的几个独特阶段的经历，包括启动阶段、初学者阶段、保存阶段和强化阶段。参与者还描述了收集肌肉锻炼行为信息的独特方法，以及他们自己驱动其行为的分析和决策过程。这项研究的结果通过概念化青少年和年轻人参与肌肉锻炼行为的新颖过程理论，扩展了先前的理论和研究，对研究和实践产生了重要影响。