Aerobic performance, haemoglobin content, and body mass of experimentally infected and sham-treated (non-infected) great reed warblers during sequential phases of infection with Plasmodium relictum. The aerobic performance is described as oxygen consumption (V̇O2, in ml min−1) during overnight rest (RMR), and during strenuous exercise (MMR), as well as the endurance of exercise period (time until exhaustion, min). Infected individuals during acute and chronic infection phases (early and late post-inoculation) did not differ from the control group, with all birds showing increasing whole-body metabolic rates and haemoglobin concentrations during the course of the experiment. Data are medians ± 25/75%.