Prospective associations of physical fitness and cognitive performance among inpatients with Schizophrenia

There is a paucity of longitudinal research investigating fitness and cognitive performance in people with schizophrenia. This study examined the prospective associations of physical fitness and cognitive performance among inpatients with schizophrenia. A prospective cohort study over two years was undertaken in 190 inpatients with schizophrenia. Four domains of physical fitness (body composition, muscle endurance, flexibility, and cardiovascular fitness) were measured at baseline in addition to the cognitive domains of attention, hand dexterity and working memory. At baseline, compared to general population normative data, more than one third of the sample had poor cardiovascular fitness, and over half were overweight/obese, had poor muscular fitness and poor flexibility. In the schizophrenia sample, better cardiovascular fitness at baseline was significantly associated with better attention, dexterity, and memory. However, the relationships dissipated after adjusting for baseline cognitive scores. In the final models, aside from baseline cognitive scores, only illness duration was significantly associated with dexterity, and smoking status and duration of hospitilization were associated with working memory. Our data suggest that in a cohort of people with established schizophrenia who already had evidence of cognitive dysfunction, better physical fitness was not associated with improved cognitive performance over two years.