# Daily Physical Activity Does Not Contribute to Differences in Muscle Oxidative Capacity Between Overweight and Obesity

## TL;DR

Overweight individuals have better muscle function than obese individuals, but physical activity levels don't explain this difference.

## Contribution

Shows that physical activity doesn't drive muscle function differences between overweight and obese individuals.

## Key findings

- Overweight individuals had higher muscle oxidative capacity than obese individuals.
- Obese non-Hispanic Black men had lower muscle oxidative capacity than overweight non-Hispanic Black men.
- No link was found between physical activity and muscle oxidative capacity in overweight or obese individuals.

## Abstract

The interaction between physical activity, skeletal muscle health, and adiposity has been explored in normal weight and overweight/obesity grouped together; however, the overall risks associated with being overweight are less than those observed with obesity and can be confounded by disparities in both sex and race. Thus, the present study sought to investigate the intricate interplay of daily physical activity and skeletal muscle oxidative capacity (SMOC) in overweight and obesity, while exploring how sex and race impact this dynamic relationship.

One hundred and forty participants were grouped by body mass index (BMI) as overweight (n = 73; BMI >25–<30 kg/m2) or obese (n = 67; BMI ≥30 kg/m2). SMOC was assessed using near‐infrared spectroscopy and daily physical activity was assessed for 7 days using accelerometry.

Overweight individuals exhibited a higher (p = 0.004) SMOC and engaged in more (p = 0.007) vigorous physical activity compared to obese individuals. In addition, SMOC was lower (p = 0.005) in obese non‐Hispanic Black (NHB) men compared to overweight NHB men. No relationships between physical activity and SMOC were observed.

Physical activity is not associated with differences in SMOC in overweight and obesity. Obese individuals engage in less vigorous physical activity and exhibit lower SMOC compared to overweight individuals and these differences are emphasised in NHB men.

Overweight individuals exhibit higher skeletal muscle oxidative capacity and engage in more vigorous physical activity compared to their obese counterparts. No correlation between physical activity and muscle oxidative capacity were observed and suggest that factors beyond increased activity contribute to greater muscle oxidative capacity in overweight versus obese individuals.