Table 1 Criterion and Fitbit-estimated step counts (upper panel) and energy expenditure (lower panel) across treadmill speeds
From: Validation of the Fitbit One® for physical activity measurement at an upper torso attachment site
Exercise phase | Observed step counts (steps)a | Fitbit One® upper torso | Fitbit One® hip | Fitbit Flex® wrist | |||
|---|---|---|---|---|---|---|---|
Estimated step counts | Percent error | Estimated step counts | Percent error | Estimated step counts | Percent error | ||
Slow walk (1.9 mph) | 98.2 ± 7.4 | 94.4 ± 6.8 | −3.1 ± 7.8 | 96.2 ± 7.6* | −1.5 ± 2.8 | 83.2 ± 25.1*‡ | −15.8 ± 27.9 |
Moderate walk (3.0 mph) | 117.7 ± 6.1 | 117.0 ± 6.4 | −0.6 ± 1.3 | 116.9 ± 6.4 | −0.6 ± 1.2 | 106.2 ± 14.9*‡ | −10.2 ± 12.3 |
Brisk walk (4.0 mph) | 132.8 ± 7.4 | 132.1 ± 6.8 | −0.2 ± 1.3 | 132.1 ± 7.0 | −0.2 ± 1.4 | 117.4 ± 20.1*‡ | −11.8 ± 14.7 |
Running (5.2 mph) | 164.6 ± 8.9 | 164.2 ± 9.3 | −0.1 ± 1.2 | 163.0 ± 9.9 | −0.9 ± 2.9 | 161.2 ± 12.4 | −2.1 ± 5.7 |
Exercise phase | Measured energy expenditure (kcal)b | Fitbit One® upper torso | Fitbit One® hip | Fitbit Flex® wrist | |||
|---|---|---|---|---|---|---|---|
Estimated energy expenditure (kcal) | Percent error | Estimated energy expenditure (kcal) | Percent error | Estimated energy expenditure (kcal) | Percent error | ||
Slow walk (1.9 mph) | 2.8 ± 0.5 | 2.5 ± 0.4* | −9.7 ± 14.9 | 2.6 ± 0.4* | −7.8 ± 15.2 | 5.2 ± 1.4*‡ | 83.4 ± 45.2 |
Moderate walk (3.0 mph) | 3.8 ± 0.8 | 4.4 ± 1.0* | 17.7 ± 37.2 | 4.1 ± 1.1 | 12.9 ± 43.3 | 6.4 ± 0.8*‡ | 68.3 ± 29.9 |
Brisk walk (4.0 mph) | 5.6 ± 1.4 | 6.4 ± 1.2* | 19.9 ± 44.2 | 6.0 ± 1.2‡ | 12.1 ± 45.0 | 7.2 ± 1.4*‡ | 29.4 ± 33.2 |
Running (5.2 mph) | 8.3 ± 2.6 | 9.5 ± 2.4 | 10.8 ± 35.3 | 7.9 ± 1.2‡ | −3.4 ± 32.8 | 10.6 ± 1.3*‡ | 24.5 ± 28.0 |