Here's a summary from the Los Angeles Times of a study conducted by researchers at the University of Illinois, published on September 11:
[T]hey recruited 48 kids who were 9 or 10 years old and asked them to learn the names of 10 fictional regions on a made-up map.
Half of the children in the study ranked in the top 30% of fitness (as measured by a treadmill test) for kids their age and gender; the other half ranked in the bottom 30%. Other than that, the kids in both groups were basically the same in terms of socioeconomic status, ADHD symptoms and scores on an intelligence test. In both groups, about half were boys and half were girls.
The children spent one day using iPads to learn the geography of the fictitious maps. In some cases, the learning was reinforced by short quizzes; in others, there was only memorization. Their recall was tested the following day.
Overall, the kids who were physically fit got an average score of 54.2% and the kids who were not fit got an average score of 44.2%. The difference was more pronounced when children were asked to remember the map they had learned without the benefit of quizzes – the fit kids scored 43% on average, while the unfit kids scored 25.8% on average.
Those results suggested to the researchers that “higher levels of fitness have their greatest impact in the most challenging situations.” They also speculated that most of the benefits of being physically fit come into play when a child is committing new information to memory, and not as much when that information is recalled later.
You can find the full study at this LINK, where the researchers conclude:
This conclusion is consistent with both the animal and human studies, which suggest that fitness and exercise has a significant influence on hippocampal structure and function. Hippocampus is responsible, in part, for encoding information into memory, and in particular for relations among different aspects of the environment (e.g., such as a face, with a name, with a profession). Indeed, the encoding and representation of region names with locations in the present study is clearly the kind of information that has been shown to be well served by a highly functioning hippocampus.