Background: The prevalence of smartphone addiction among young adults, particularly within university populations, has emerged as a significant public health concern due to its association with sedentary behavior and increased risk for non-communicable diseases (NCDs). Given that the physiotherapy profession is inherently physically demanding requiring practitioners to maintain a high level of physical fitness to effectively perform clinical assessments and therapeutic interventions. It is imperative to investigate whether excessive smartphone use compromises the health-elated physical fitness (HRPF) of students training in this field. This study aims to examine the association between smartphone use, both in terms of addiction status and daily usage duration, and HRPF components among undergraduate physiotherapy students at Kathmandu University School of Medical Sciences (KUSMS), Dhulikhel, Nepal.

Methods: A cross-sectional study design was employed, with an initial sample of 115 participants; six were subsequently excluded due to incomplete data, resulting in a final analytic sample of 109 students. Smartphone addiction was assessed using the validated Smartphone Addiction Scale -Short Version (SAS-SV). Health-related physical fitness was evaluated across five key domains: body composition (via skinfold thickness measurements), cardiorespiratory endurance (using the YMCA 3-minute step test), muscular strength (assessed by the push-up test), muscular endurance (measured by the partial curl-up test), and flexibility (determined by the YMCA sit-and-reach test). Data analysis included descriptive statistics, chi-square tests for categorical associations, and Spearman’s rank correlation coefficients to examine relationships between continuous variables, with statistical significance defined as p < 0.05.

Results: The results indicated a high prevalence of smartphone addiction, affecting 45.9% of the participants. Performance on HRPF components revealed suboptimal outcomes in body composition (48.6%), cardiorespiratory endurance (52.3%), and flexibility (61.5%). In contrast, muscular strength was rated as average in 57.8% of students, while muscular endurance was classified as excellent in 70.6%. Notably, no statistically significant association was found between smartphone addiction status and any of the five HRPF components (p > 0.05). However, a significant negative correlation was observed between the daily duration of smartphone use and three specific fitness parameters: muscular strength (r = -0.24, p = 0.01), muscular endurance (r = -0.22, p = 0.02), and flexibility (r = -0.19, p = 0.04).

Conclusion: A substantial proportion of physiotherapy students exhibit smartphone addiction, and most health-related physical fitness components are below average, potentially compromising health and increasing the risk of future musculoskeletal injuries.