Reliability and Validity of Physical Performance Tests in Individuals With Obesity

Clinician-Friendly Physical Performance Tests in Individuals With Obesity: Reliability and Validity

This study aims to investigate the reliability and validity of practical performance-based physical function tests in individuals with obesity. Functional limitations such as reduced walking ability, impaired balance, and decreased lower extremity strength are common in people with obesity and may negatively affect daily activities and quality of life.

Participants will complete several commonly used clinical functional tests, including the 1-Minute Stair Climbing Test, 40-Meter Fast-Paced Walk Test, 2-Minute Walk Test, Timed Up and Go Test, and 30-Second Sit-to-Stand Test. In addition, cardiopulmonary exercise testing, balance assessment, and knee extensor muscle strength measurements will be performed.

The study will evaluate whether these simple and clinically applicable tests provide reliable results over repeated measurements and whether they are associated with objective indicators of physical function such as maximal oxygen consumption (VO₂max), balance performance, and muscle strength. The findings may help clinicians use practical and cost-effective tools to assess physical function in individuals with obesity.

Inclusion Criteria:

• Body mass index (BMI) ≥ 30 kg/m²
• Stable body weight during the last 3 months (less than ±2 kg change)
• Ability to perform daily living activities independently

Exclusion Criteria:

• History of cardiovascular disease
• History of pulmonary disease
• History of neurological disease
• Musculoskeletal injury affecting lower extremity function
• Presence of lower extremity prosthesis or severe deformity
• Major surgery within the previous 6 months
• Pregnancy
• Postpartum period
• Vestibular disorders affecting balance
• Visual impairments affecting test performance
• Hearing impairments affecting test performance
• Cognitive impairment limiting understanding of instructions
• Participation in strenuous physical activity before testing
• Use of medications affecting cardiopulmonary responses (e.g., beta-blockers)