Invited Commentary on: ‘Gait and increased body weight (potential implications for musculoskeletal disease)’, Sheehan and Gormley. Obesity is partly attributable to a low level of physical activity leading to insufficient total daily energy expenditure. Accordingly, increasing levels of physical activity is one of the key challenges in the prevention and treatment of obesity.1 To date, studies report only modest adherence to physical activity in obese individuals. These persistently low levels of daily physical activity may be attributed to physiological and biomechanical factors that limit gait performance.