A new equation based on the 6-min walking test to predict VO_2peak in women with obesity

Abstract

Objective: The 6-min walking test (6 MWT) is commonly used to assess obese patients’ aerobic fitness, but it has rarely been compared with a direct measurement of maximal aerobic capacities (VO_2max or VO_2peak) in obese adults. The aim of this study was to investigate the relationship between the distance covered during a 6 MWT with objectively measured VO_2peak and to propose a new equation to predict VO_2peak from this walking test in obese patients.

Methods: One hundred and thirty-seven obese patients (45.6 ± 12.5 years) admitted to our hospital for a multidisciplinary rehabilitation program were enrolled. After assessment of their body composition, the participants were asked to perform a 6 MWT and their maximal aerobic capacities (VO_2peak) were measured.

Result: There is a significant linear relation between VO_2peak and the distance covered during the 6 MWT (p < 0.001; r = 0.349). The determinant of VO_2peak was body mass index, waist-to-hip ratio, fat free mass, leading to the follow prediction equation VO_2peak such as VO_2peak (l/min) = (body mass index ×0.0150065) − (waist-to-hip-ratio × 0.8595088) + (fat-free-mass × 0.0295478) + (6-min walk test ×0.0020672) − 0.5853372.

Conclusion: The 6-min walk test is a reliable method to reflect obese women’s aerobic capacities and the distance covered can be used to accurately estimate VO_2peak according to our newly proposed equation.

Implication for rehabilitation

• Obesity is a worldwide disease and physical capacity evaluation is a key point for rehabilitation.

• The six minutes’ walk test is commonly used in obese people to assess aerobic fitness.

• This study proposes a new equation using 6 MWT performance to estimate VO_2peak.

Keywords:

• Obesity
• exercise
• 6-min walking test
• aerobic capacity

Acknowledgements

We are grateful to all patients for their participation and to physiotherapists for help with the testing.

Disclosure statement

The authors declare that they have no conflicts of interest concerning this article