Background Head impacts, particularly, non-concussive impacts, are common in sport. Yet, their effects on the brain remain poorly understood. Here, we investigated the acute effects of non-concussive impacts on brain microstructure, chemistry, and function using magnetic resonance imaging (MRI) and other techniques. Results Fifteen healthy male soccer players participated in a randomised, controlled, crossover pilot trial. The intervention was a non-concussive soccer heading task (‘Heading’) and the control was an equivalent ‘Kicking’ task. Participants underwent MRI scans ~ 45 min post-task which took ~60 min to complete. Blood was also sampled, and cognitive function assessed, pre-, post-, 2.5 h post-, and 24 h post-task. Brain chemistry: Heading increased total N-acetylaspartate (p = 0.012; g = 0.66) and total creatine (p = 0.010; g = 0.77) levels in the primary motor cortex (but not the dorsolateral prefrontal cortex) as assessed via proton magnetic resonance spectroscopy. Glutamat