Resilience: recovery speed
Resilience is how quickly a person's everyday measures return toward their usual level after a dip, estimated from natural day-to-day recoveries (Scheffer et al., 2018).
The formula
x(t+1) = φ · x(t) + ε
recovery rate λ = −ln φ half-life t½ = ln 2 / λ
Under an AR(1) approximation of the detrended series, φ is the lag-1 autocorrelation. If φ is 0 or less, or 1 or more, the output is "not estimable". The rate is consistent with recovery as 1 − AR1 (Dakos et al., 2012).
Defaults
| Parameter | Default |
|---|---|
| Series | Nightly lnRMSSD, detrended |
| Window | 60 days |
| Affect variant | Recovery after at least 5 self-reported stressor episodes |
A worked example
If φ = 0.6, then λ = −ln 0.6 ≈ 0.51 per day, and the half-life is ln 2 / 0.51 ≈ 1.36 days: about half of a dip has recovered within a day and a half. These numbers are illustrative.
Questions
Is a longer half-life a problem?
It describes slower recovery relative to the person's own pattern. It is a research and wellness measure, not a clinical finding.
Sources
Keep reading
Take the next step.
How ATS-1 measures resilience as recovery speed: an AR(1) model of nightly HRV gives a recovery rate λ = −ln φ and a half-life t½ = ln 2 / λ over 60 days.