Table 4. Validity of the wrist-worn activity trackers for estimating daily physical activity (i.e., steps, moderate-to-vigorous, and total physical activity) during unstructured free-living conditions (n = 51).
| Instrument |
Mean (SD) |
Equivalence test (90% CI) |
LOA (95% CI) |
MAE |
MAPE |
ICC (95% CI) |
| Steps (n) |
| ActiGraph wGT3X-BT |
6562.1 (2662.6) |
-984.32, 984.32 |
- |
- |
- |
- |
| Samsung Galaxy Watch Active 2 |
6290.2 (3002.1) |
77.8, 466.0 |
271.9 (-1349.2, 1893.0) |
679.3 |
11.4 |
0.95 (0.92, 0.97) |
| Apple Watch Series 5 |
7316.0 (2886.6) |
-1012.4, -495.4 |
-753.9 (-2912.8, 1405.0) |
1001.1 |
18.0 |
0.89 (0.69, 0.95) |
| Xiaomi Mi Band 5 |
6688.0 (3155.9) |
-347.5, 95.7 |
-125.9 (-1976.7, 1724.9) |
591.7 |
9.4 |
0.95 (0.91, 0.97) |
| Moderate-to-vigorous physical activity (min) |
| ActiGraph wGT3X-BT |
41.8 (17.8) |
-6.27, 6.27 |
- |
- |
- |
- |
| Apple Watch Series 5 |
36.3 (20.8) |
3.30, 7.59 |
5.4 (-12.4, 23.2) |
8.2 |
22.6 |
0.86 (0.67, 0.93) |
| Xiaomi Mi Band 5 |
65.8 (41.8) |
-34.05, -13.93 |
-24.0 (-108.1, 60.1) |
37.8 |
120.6 |
0.09 (0.00, 0.31) |
| Xiaomi Mi Band 5a |
21.3 (15.3) |
17.85, 23.07 |
20.5 (-1.3, 42.3) |
20.7 |
53.5 |
0.44 (0.00, 0.77) |
| Total physical activity (min) |
| ActiGraph wGT3X-BT |
216.1 (61.5) |
-32.42, 32.42 |
- |
- |
- |
- |
| Samsung Galaxy Watch Active 2 |
70.3 (36.6) |
134.0, 158.0 |
145.8 (44.1, 247.5) |
145.8 |
67.6 |
0.09 (0.00, 0.32) |
| Xiaomi Mi Band 5 |
83.0 (34.4) |
122.0, 144.0 |
133.0 (37.7, 228.3) |
133.0 |
61.3 |
0.12 (0.00, 0.38) |
| Xiaomi Mi Band 5b |
64.6 (38.4) |
140.0, 163.0 |
151.5 (52.3, 250.7) |
151.5 |
70.6 |
0.10 (0.00, 0.34) |
SD = Standard deviation; LOA = Limits of agreement; 90%/95% CI = 90%/95% confident interval; MAE = Mean absolute error; MAPE = Mean absolute percentage error; ICC = Intraclass correlation coefficient;
a Brisk walking time (min);
b Slow-brisk walking time (min).
