Another key was focusing specifically on episodic memory, which is supported by a part of the brain that's known to benefit from exercise. "When we combine and merge all this data, it allows us to examine almost 3,000 participants," Aghjayan said. "Each individual study is very important: They all contribute to science in a meaningful way." Individual studies, however, may fail to find patterns that actually exist because of a lack of resources to run a big enough experiment. The studies individually couldn't find a link between exercise and memory -- it took looking at the whole body of research to bring the pattern into focus. With that much larger pool of participants, the team was able to show a link between exercise and episodic memory but also was able to start to answer more specific questions about who benefits and how.