Impact of Muscle Mass and Muscle Strength on Quality of Life of Individuals with Intellectual and Developmental Disabilities  
[PERSON]  
1 ESES, Polytechnique of Leiria, 2411-901 Leiria, Portugal, [EMAIL_ADDRESS] (M.J.);  
[EMAIL_ADDRESS] (D.M.J. ; [EMAIL_ADDRESS] (S.D. ); [EMAIL_ADDRESS] (R.M. );  
[EMAIL_ADDRESS] (N.A. ); [EMAIL_ADDRESS] (R.A.)  
[PERSON]  
1 ESES, Polytechnique of Leiria, 2411-901 Leiria, Portugal, [EMAIL_ADDRESS] (M.J.);  
[EMAIL_ADDRESS] (D.M.J. ; [EMAIL_ADDRESS] (S.D. ); [EMAIL_ADDRESS] (R.M. );  
[EMAIL_ADDRESS] (N.A. ); [EMAIL_ADDRESS] (R.A.)  
[PERSON]  
3 Polytechnic Institute of Castelo Branco, 6000-084 Castelo Branco, Portugal  
individuals with IDD is a way of giving them a voice, respecting their perceptions and experiences, which is essential for their development, while always respecting their rights and responsibilities [1,3]. Muscle strength has a fundamental role to performance in lives of individuals with IDD, directly influencing their functionality, independence and quality of life [5,6]. These individuals have deficits in muscle strength, which can affect their motor skills, coordination, balance and resistance [7,8]. These limitations can make it difficult to successfully perform basic activities such as walking, climbing stairs, dressing and carrying out domestic tasks, increasing dependence on carers. In addition, reduced muscle strength in this population is associated with less autonomy and a higher incidence of early fatigue, negatively affecting self-esteem and perceived quality of life [9]. Understanding the relationship between muscle strength and quality of life in this population is crucial for developing effective and adapted interventions aimed at promoting greater independence and well-being [5,6]. These individual characteristics become more accentuated due to the inactive and sedentary lifestyles often observed in the IDD population [10,11]. Although the World Health Organization recommends that adults with IDD engage in at least 150 min of moderate-intensity physical activity per week, or 75 min of intense physical activity and muscle-strengthening activities on two or more days per week, this population does not meet the recommendations [10]. Not only does this increase the risk of developing cardiovascular and metabolic diseases, but it also compromises mobility and independence, negatively affecting quality of life. The lack of adherence to and maintenance of physical activity programs may be due to the existence of barriers/obstacles/constraints that can hinder practice [12]. It is important to analyze quality of life and function from various perspectives in the field of rehabilitation [13,14]. Despite the potential benefits of muscle strength in individuals with IDD, its relationship with perceived quality of life is still little explored in the scientific literature. Most of the literature focuses on specific physical health variables, such as functional capacity, reducing the risk of falls or preventing chronic diseases, without necessarily considering the direct impact of these variables on the quality of life of this population. Muscle strength is known to be related to greater functional independence, making it easier to carry out daily activities and perform tasks independently [5,6]. However, the lack of studies correlating these variables with subjective quality of life indicators means there is a gap in the literature. This study aims to analyze the correlation between muscle strength and perceived quality of life in adults with IDD. Understanding this relationship is crucial for developing more effective, personalized interventions that not only promote physical health but also enhance the well-being and overall life satisfaction of this population. By highlighting the potential link between muscle strength and quality of life, this study aims to underscore the importance of incorporating physical activity and muscle strengthening into health promotion strategies for individuals with IDD.