Smartlife’s validation study in May 2018 proved that our technology provides an accurate measure of HR during exercise. Smartlife HR strongly correlated with ECG HR (r >.95) and Polar HR (r >.95) during graded walking and running, respectively.
Twenty-five healthy adults (18 males, 7 females) who were accustomed to regular (>=75 mins/wk) vigorous exercise. Mean ± SD for age, height, body mass, and body mass index were: 27 ± 8 years, 80.3 ± 18.6 kg and 1.75 ± 0.8 m, respectively.
Test 1: Smartlife vs ECG* Incremental walking protocol (6kph) whereby the gradient was increased by 3% at 3 minute intervals to a maximum of 14% (5 stages). HR manually recorded from the Smartlife app on a smartphone and ECG1 exactly 10 seconds before the end of each stage.
Test 2: Smartlife vs Polar** Incremental running protocol consisting of 4 x 3-minute stages at 9, 10, 11 and 12 kph. HR from each device was manually recorded from the Smartlife and Polar2 apps on separate smartphones exactly 10 seconds before the completion of each stage.
Pearson correlation coefficients (r) and standard error of estimates (SEE) were calculated to determine the validity of Smartlife. Previous HR devices have been considered valid if the correlation coefficient between the criterion instrument and HR device was ≥0.90, with a corresponding SEE ≤5 b·min– 1 (Leger & Thivierge, 1988).
*Vyntus ECG, JAEGER, Würzburg, Germany
**Polar H7, Polar Electro Oy, Kempele, Finland