Field based reliability and validity of the bioharness™ multivariable monitoring device

The bioharness™ device is designed for monitoring physiological variables in free-living situations but has only been proven to be reliable and valid in a laboratory environment. therefore,this study aimed to determine the reliability and validity of the bioharness™ using a field based protocol. twenty healthy males participated. heart rate (hr),breathing frequency (bf) and accelerometry (acc) were assessed by simultaneous measurement of two bioharness™ devices and a test-retest of a discontinuous incremental walk-jog-run protocol (4 - 11 km·h-1) completed in a sports hall. adopted precision of measurement devices were; hr: polar t31 (polar electro),bf: spirometer (cortex metalyser),acc: oxygen expenditure (cortex metalyser). for all data,precision of measurement reported good relationships (r = 0.61 to 0.67,p < 0.01) and large limits of agreement for hr (>79.2 b·min-1) and bf (>54.7 br·min-1). acc presented excellent precision (r = 0.94,p < 0.01). results for hr (r= ~0.91,p < 0.01: cv <7.6) and acc (r > 0.97,p < 0.01; cv <14.7) suggested these variables are reliable. bf presented more variable data (r = 0.46-0.61,p < 0.01; cv < 23.7). as velocity of movement increased (>8 km·h-1) data became more erroneous. a data cleaning protocol removed gross errors in the data analysis and subsequent reliability and validity statistics improved across all variables. in conclusion,the bioharness™ hr and acc variables have demonstrated reliability and validity in a field setting,though data collected at higher velocities should be treated with caution. measuring human physiological responses in a field based environment allows for more ecologically valid data to be collected and devices such as the bioharness™ could be used by exercise professionals to begin to further investigate this area. © journal of sports science and medicine.