Background <p>While the benefits of muscle-strengthening activities are well established, national surveillance data suggest that women do fewer muscle-strengthening activities than men. The study aimed to understand the barriers and facilitators to participation in muscle-strengthening exercise among women aged 18 to 64 who are currently meeting the muscle-strengthening guidelines, and to identify strategies to improve involvement in these activities.</p> Methods <p>24 women, aged 18 to 64, from the United Kingdom who participated in muscle-strengthening exercises at least two days per week were invited to an online or in-person interview. A qualitative study using reflexive thematic analysis was used to identify key themes related to the barriers and facilitators of participation, as well as potential strategies to improve participation.</p> Results <p>Qualitative findings revealed four overarching themes: (1) reason for participating in muscle-strengthening exercises (health concerns and sports performance), (2) barriers to muscle-strengthening exercise participation (perceived time constraint, low motivation, cultural stigma and societal perceptions, confidence in ability and accessibility), (3) facilitators to participating in muscle-strengthening exercises (resources or information, accountability, social support, ability to choose and positive changes) and (4) strategies to improve women’s participation in muscle-strengthening exercises (what an individual and others can do).</p> Conclusion <p>This study enhances understanding of women’s engagement in muscle-strengthening exercises by highlighting how individual, social, and physical environments interact to influence participation. Findings suggest that strategies are needed that target all levels of influence to help increase participation in muscle-strengthening exercises.</p>