Early modern diaries and letters are replete with complaints about the state of the body after illness. ' A long sicknes … has much drained mee … and indeed … my feeble hands … can scarce write', remarked Rev. Thomas Lowgh from Cumbria in 1654. 1 A few years later, the London gentlewoman Ann Fanshawe recorded in her memoirs, 'a very ill kind of fever … brought me so low that I was like an anatomy'. 2 In 1697, Elizabeth Freke from Norfolk lamented, 'God raised me up againe a miserable spectt[ac]le … hardly able to goe or stand'. 3 Serious physical illness thus left the body weak and lean, full of the 'footsteps of disease', to use the early modern term. It was not until full strength and flesh had returned that the patient was pronounced back to health. This chapter asks how doctors and laypeople measured the patient's growing strength after illness, and analyses the physiological processes through which this restitution was thought to occur. It shows that both the measures and the mechanisms for the restoration of strength were intimately connected to the 'six Non-Natural things': excretion, sleep, food, passions, air and exercise. Patients' sleeping patterns, appetites for foods, and emotions, along with other inclinations and behaviours that related to the Non-Naturals, were used to track their progression on 'the road to health'. Medical practitioners and the patient's family sought to regulate each Non-Natural in order to promote the body's restoration, and 4