Breakpoint regression results (shown as partial correlation coefficients) for the effects of age onV̇O2max andV̇O2sum in deer mice ranging in age from 27 days to 1863 days
| . | Age breakpoint . | Age < breakpoint . | Age > breakpoint . |
|---|---|---|---|
| V̇ O2max | 485 days | N=83 | N=125 |
| Mass: r=0.774, P<0.000001* | Mass: r=0.569, P<0.000001* | ||
| Age: r=-0.103, P=0.36 | Age: r=-0.291, P=0.00102* | ||
| V̇ O2sum | 483 days | N=82 | N=124 |
| Mass: r=0.621, P<0.000001* | Mass: r=0.419, P=0.000015* | ||
| Age: r=-0.046, P=0.68 | Age: r=-0.410, P=0.000024 |
| . | Age breakpoint . | Age < breakpoint . | Age > breakpoint . |
|---|---|---|---|
| V̇ O2max | 485 days | N=83 | N=125 |
| Mass: r=0.774, P<0.000001* | Mass: r=0.569, P<0.000001* | ||
| Age: r=-0.103, P=0.36 | Age: r=-0.291, P=0.00102* | ||
| V̇ O2sum | 483 days | N=82 | N=124 |
| Mass: r=0.621, P<0.000001* | Mass: r=0.419, P=0.000015* | ||
| Age: r=-0.046, P=0.68 | Age: r=-0.410, P=0.000024 |
Regressions were derived from loge-transformed mass, age,maximal oxygen consumption in exercise(V̇O2max) and maximal oxygen consumption in thermogenesis(V̇O2sum); nearly identical results were obtained when regressions were based on mass-corrected V̇O2(Fig. 4). The overall r values (including the effects of both mass and age and combined across both age groups) were 0.85 for V̇O2max and 0.805 for V̇O2sum. P values with an asterisk (*) remained significant after sequential Bonferroni correction (adjusted α=0.017).