The field of sports psychology is awash with research on how the brain can affect physical performance. But how does intense exercise affect brain function? That’s the question that US scientists have been looking at in a study on how maximal treadmill running affects subsequent cognitive function in recreational athletes.

In the study, 102 male and female athletes were recruited and then split into two groups; the exercise group performed a 15-minute incremental treadmill run right up to the limit of their maximum oxygen uptake (ie to exhaustion). The control group meanwhile simply rested for 15 minutes. Immediately before and following these two experimental conditions, all the subjects were asked to perform a neuropsychological test battery called ‘Immediate Post-Concussion Assessment and Cognitive Testing’ (ImPACT), which measures neurocognitive function and fatigue symptoms. The results of these tests were as follows:

• The verbal memory scores in the running group decreased following the VO2max test; in particular, immediate recall memory and delayed recall memory were significantly worse after the test compared to the controls;
• A prolonged memory effect was also shown to occur as it took three days for the running group to fully recover their baseline scores;
• No significant differences between the runners and controls were found for visual memory, motor processing speed and reaction times.

These results are somewhat surprising as you might expect motor processing speed and reaction times rather than memory to be adversely affected following maximal exercise, but this doesn’t appear to be the case. There are also implications for athletes; the best time for learning new skills, particularly where verbal tuition forms part of the process may not be after high-intensity training sessions or competition, but instead well away from these times in a well-rested state.

Br J Sports Med 2007; 15 (Epub ahead of print)