Checklist of items that need to be considered when planning validity protocols for consumer heart rate wearables
| Target population | |
| BMI | Ο |
| Body height | Ο |
| Skin tone | Ο |
| Sex | Ο |
| Sample size calculation via pilot study | Ο |
| Criterion measure | |
| Chest strap or ECG | Ο |
| Placement according to manufacturer’s instructions | Ο |
| Index device | |
| Placement according to manufacturer’s instructions | Ο |
| Pretest preparations | |
| Standardised meal replacement | Ο |
| Control caffeine intake | Ο |
| Medical screening | Ο |
| Exclude participants with medication affecting cardiovascular function | Ο |
| Control for previous intense physical activity | Ο |
| Testing: laboratory conditions | |
| Minimum of 3 walking intensities | Ο |
| Minimum of 2 running intensities | Ο |
| Minimum of 3 biking intensities | Ο |
| Steady-state (2–5 min) | Ο |
| HR kinetics (transitions and recovery) | Ο |
| Validity level | |
| 1. Graded ergometer test with a wide range of exercise intensities reported as % of HRmax (or VO2max) including rest and recovery | Ο |
| 2. Graded ergometer test with a wide range of exercise intensities in absolute values (ie, speed/incline, W/rpm) including rest and recovery | Ο |
| 3. Graded ergometer test with a moderate range of exercise intensities as % of HRmax (or VO2max) including rest and recovery | Ο |
| 4. Graded ergometer test with a moderate range of exercise intensities reported in absolute values (ie, speed/incline, W/rpm) including rest and recovery | Ο |
| 5. Graded ergometer test with a low range of exercise intensities reported as % of HRmax (or VO2max) including rest and recovery | Ο |
| 6. Graded ergometer test with a low range of exercise intensities reported in absolute values (ie, speed/incline, W/rpm) including rest and recovery | Ο |
| Testing: semifree-living (sport-specific) conditions | |
| Intermittent activities (ie, soccer, basketball, etc) | |
| 1. Inherent environmental conditions (eg, standard playing field, etc) | Ο |
| 2. Inherent no of players included | Ο |
| 3. Inherent duration with a minimum of 15–20 min | Ο |
| Continuous activities (running, walking, biking, swimming) | |
| 1. Minimum of three intensities (40 %, 60 %, 80% of HRmax) | Ο |
| 2. Inherent duration with a minimum of 2 min of each intensity | Ο |
| Activities with domestic behaviour (doing laundry, gardening, home construction) | |
| 1. Minimum of 15–20 min | Ο |
| Testing: free-living conditions | |
| Subject’s wear index and criterion device for a minimum of 24 hours | Ο |
| Exclude subject’s not presenting HR data above 40% of HRmax | Ο |
| Exclude recordings missing more than 5% of the data (index or criterion device) | Ο |
| Processing | |
| Criterion measure processing | |
| 1. Apply an automated method for filtering ectopic beats and motion artefacts | Ο |
| Index measure processing | |
| 1. No post processing of the end-user data is allowed | Ο |
| 2. Resampling into a window of 5 s is allowed | Ο |
| Epochs for analysis/window size | |
| 1. Sample criterion measure with same epoch as available with the index measure | Ο |
| 2. Window size should be 5 s or shorter | Ο |
| Index and criterion synchronisation | |
| 1. Automated method for synchronisation (cross correlation or similar) | Ο |
| Statistical analysis | |
| Standard Bland-Altman LoA analysis for steady-state conditions | Ο |
| Repeated measure LoA analysis for non-steady state conditions (multiple paired observations of HR epochs per individual) | Ο |
| Evaluate within-device precision by comparing the within-person variability in average HR over 5 s windows separately for steady-state activity of at least 2 min duration | Ο |
BMI, body mass index; HR, heart rate; HRmax, maximal heart rate; LoA, limits of agreement; rpm, repetitions per minute; VO2max, maximal oxygen uptake; W, Watts.