OBJECTIVE Exposure to acute 'stressors' (e.g. infections, pain, trauma) often results in altered sleep habits and reductions in routine activity. In some individuals, these behavioural responses to acute stressors may contribute to the development of chronic somatic symptoms such as widespread pain, fatigue, memory difficulties and mood disturbances, much like those associated with 'functional somatic syndromes' (FSS) such as fibromyalgia or chronic fatigue syndrome. METHODS Eighty-seven healthy young adults who reported sleeping between 7 and 9 hours nightly and exercising regularly were randomised to one of four groups: exercise cessation, sleep restriction (6 hours nightly), both, or neither. Symptoms of pain, fatigue, cognitive dysfunction and negative mood were measured before and after the 10-day restriction period. RESULTS Sleep restriction was a potent contributor to the development of somatic symptoms. Exercise cessation was less influential leading only to fatigue. There were no significant interactions between exercise cessation and sleep restriction, except that males were much more likely to develop somatic symptoms when deprived of both sleep and exercise than one or the other. Women were generally much more likely to develop somatic symptoms than men. CONCLUSIONS This study supports previous research suggesting that both sleep and exercise are critical in 'preventing' somatic symptoms among some individuals. Furthermore, to our knowledge, this is the first time there is data to suggest that women are much more sensitive to decrements in routine sleep and exercise than are men.