1-s epoch | 5-s epoch | 15-s epoch | 30-s epoch | 60-s epoch | |
---|---|---|---|---|---|

β (95% CI) | β (95% CI) | β (95% CI) | β (95% CI) | β (95% CI) | |

TBLH BMC (g) |
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^{a}Average-acceleration |
78.11 |
78.31 |
80.82 |
79.96 |
71.77 |

^{b}Intensity-gradient |
56.23 (-10.85 to 123.3) | 49.8 (-19 to 118.59) | 35.57 (-32.41 to 103.54) | 37.39 (-29.82 to 104.6) | 50.17 (-24.25 to 124.6) |

Spine aBMD (g/cm)^{2} |
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^{a}Average-acceleration |
0.02 |
0.03 |
0.03 |
0.03 |
0.02 |

^{b}Intensity-gradient |
0.04 |
0.03 |
0.02 (0.00 to 0.04) | 0.02 (0.00 to 0.04) | 0.02 (0.00 to 0.04) |

Total hip aBMD (g/cm^{2}) |
|||||

^{a}Average-acceleration |
0.03 (0.00 to 0.06) | 0.03 |
0.03 |
0.04 |
0.03 |

^{b}Intensity-gradient |
0.04 |
0.03 (-0.01 to 0.06) | 0.02 (-0.02 to 0.05) | 0.01 (-0.02 to 0.05) | 0.01 (-0.02 to 0.05) |

Femoral neck cross-sectional area (cm^{2}) |
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^{a}Average-acceleration |
0.12 (-0.01 to 0.25) | 0.12 (0.00 to 0.25) | 0.12 |
0.12 (-0.01 to 0.24) | 0.1 (-0.03 to 0.22) |

^{b}Intensity-gradient |
0.13 (0.00 to 0.27) | 0.11 (-0.03 to 0.25) | 0.09 (-0.04 to 0.23) | 0.11 (-0.02 to 0.24) | 0.14 |

Femoral neck section modulus (cm^{3}) |
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^{a}Average-acceleration |
0.06 (-0.02 to 0.14) | 0.07 (-0.01 to 0.14) | 0.07 (-0.01 to 0.15) | 0.07 (-0.01 to 0.14) | 0.05 (-0.03 to 0.13) |

^{b}Intensity-gradient |
0.09 |
0.07 (-0.01 to 0.16) | 0.06 (-0.02 to 0.13) | 0.06 (-0.02 to 0.13) | 0.09 |

Values are regression coefficients (β), their 95% confidence intervals (CI), and p values from linear regression models. Regression coefficients are adjusted for age at wave 9, stature at wave 9, mass at wave 9, years from peak height velocity at wave 9, the proportion of the 24-hour cycle the accelerometer was worn, the mean age for physical activity measures, and the alternate activity metric (intensity-gradient or average-acceleration). Activity metrics were standardised before entry into analysis, so values represent the change in the outcome associated with a 1 standard deviation change in the activity metric.

* p < 0.05.

** p < 0.01.

TBLH, total body less head; BMC, bone mineral content; aBMD, areal bone mineral density.