The bumpy trajectory of human aging may have a tipping point as we enter our twilight years, a new study has found.

Past the age of around 75, our bodies can no longer easily recover from injury or illness – a sharp decline in resilience that comes with a corresponding rise in the risk of dying, according to researchers at Dalhousie University in Canada.

Their model looks at aging as a balance between damage and repair, with the breakdown of that balance marking the point of no return into frailty.