Author(s): JONES, S., MISTURA, M.2, BURT, D.1, PHEASEY, C.1, HARRIS, J.2, REED, J.L.2, BUCKLEY, J.P.1, Institution: KEELE UNIVERSITY, Country: UNITED KINGDOM, Abstract-ID: 2312

INTRODUCTION:
Previous research from our group developed a regression equation to estimate the oxygen cost (V̇O₂) of walking at a range of velocities collected at 1 min increments on a treadmill in healthy adult participants whilst wearing a foot-pod accelerometer (StrydPower)1. This represents typical validation of wearable technology but is it applicable for older clinical populations? We aimed to compare estimated V̇O₂ from the StrydPower watts with actual V̇O₂ while patients performed their prescribed moderate intensity walking paces.
METHODS:
During the prescribed moderate aerobic walking component on an indoor track of a routine cardiac rehabilitation session, patients wore a portable pulmonary gas-exchange monitor and a StrydPower. Along with the continuous gas exchange variables, walking watts, heart rate, and ratings of perceived exertion were also collected continuously for a minimum of 10 mins. Mean data for the last two minutes of the walking were analysed. Analysis of agreement between actual V̇O₂ and that estimated from our existing StrydPower watts/V̇O₂ regression equation, included a T-test, intra-class-correlation coefficient (ICC) and bias +/-95 Limits of Agreement (LoA).
RESULTS:
Seventeen participants completed the study (7 female, 67.1 +/-14.9 years). The difference in actual vs estimated V̇O2 was clinically small but significant, (16.7 +/-3.3 and 14.5+/-3.2 ml·kg-1·mins-1; p = .003). The related ICC was moderate and significant (r = .53, p = .01) and the bias +/- 95%LoA was 2.2 +/- 5.0 ml·kg-1·mins.
CONCLUSION:
The use of a StrydPower foot pod accelerometer to estimate the oxygen cost of moderate intensity walking in a group of cardiac rehabilitation participants showed a moderate agreement for clinical significance. However, its validity stills needs further specific precision and evaluation for older clinical populations in relation to two factors typically questioned when using commercial wearable technologies; i. the criterion data from which V̇O₂ estimates were derived were healthy young adults and ii. The criterion data were measured on a treadmill collected at 1 min intervals as opposed to longer duration steady state. Taking these factors into account shows encouraging applications for remote monitoring of walking intensity with the StrydPower in cardiac populations.

1Jones, S., Burt, D., Pheasey, C., Buckley, J (2024) ECSS Glasgow 2024: 29th Annual Congress of the European College of Sport Science, 2-5 July 2024, Glasgow, Scotland, UK ; book of abstracts. European College of Sport Science.