Six-minute walk test in healthy British service personnel

The 6 min walk test (6MWT) is a widely used, safe and effective submaximal exercise test. The primary outcome is the distance walked, but additional physiological and patient-reported metrics can be recorded. It is used to assess function and is commonly used within UK Defence Rehabilitation. However, there are no published British military 6MWT data in a non-injured population. This study reports the 6MWT procedure and results from healthy British service personnel.

A convenience sample of 46 individuals (male n=40) undertook 95 6MWTs over three study visits throughout a year. They were performed on a 20 m straight-line route, administered by an exercise rehabilitation instructor and preceded by anthropometric measurements (height, weight). Physiological measures (HR, oxygen saturations (SpO₂)) and patient-reported measures (Borg shortness of breath (SoB), rate of perceived exertion (RPE) and fatigue) were taken before and after the assessment. Statistical tests were performed between pre-test and post-test measures, and sex and body mass, and concurrent cardiopulmonary exercise tests (CPET) with 6MWT distance.

The mean 6MWT distance was 705.5±86 m; males 709.4±86.9 m and females 685.9±81.9 m (p=0.32), with a median Borg SoB of 1 (IQR: 0-2) and RPE 9 (IQR: 7-11), and a negative correlation between body mass index and 6MWT distance, p=0.007. There were no significant differences between pre-test and post-test measures. Peak workload and VO₂ Max correlated weakly with 6MWT distance (0.336, p=0.01 and 0.375, p=0.09, respectively), but submaximal CPET measures did not.

These results provide a benchmark for British military 6MWT data to guide clinical and research use. However, a larger dataset is required for validation and normative values.