Validity of thorax-worn GPS heart rate data during continuous incremental and intermittent running

Objectives To determine the level of agreement between Catapult Vector S7 and Polar H10 for measuring heart rate (HR) during continuous incremental and intermittent running. Design Concurrent validity study. Methods Twenty participants (n = 10 males, 10 females; age = 25.7 ± 4.9 years) completed a continuous incremental and intermittent running protocol on a motorised treadmill with HR measured wearing Catapult Vector S7 and Polar H10 devices. The continuous protocol involved incremental increases in speed at a fixed 1 % incline until at least 90 % of age-predicted heart rate max (HR max ) was reached. The intermittent protocol was completed following a standardised recovery period. Coefficient of determination ( R 2 ), root mean square error (RMSE), mean absolute percentage error (MAPE), mean bias, and 95 % limits of agreement (LoA) were used to measure agreement between the two devices. Results Near-perfect agreement ( R 2 = 0.99 for all participants) between the two devices was observed for the continuous and intermittent protocols. The RMSE was low for all participants, measuring 1.6 beats per minute (bpm) during the continuous protocol and 1.2 bpm during the intermittent protocol. No systematic bias was observed in either protocol when grouped by sex. Although females showed slightly higher RMSE values in both the continuous (2.2 vs 0.7 bpm) and intermittent protocols (1.5 vs 0.8 bpm), the Vector S7 validity remained high. Conclusions The Catapult Vector S7, in combination with Vector Elite 2.3 Vest, represents a highly valid alternative to chest-worn straps in measuring HR during high-intensity exercise involving continuous and intermittent running.