A systematic review of published data reported in the January issue of theArchives of Pediatrics & Adolescent Medicine finds there may be a positive link between physical activity and academic performance of children in school: the ones who are more physically active seem to do better in class. However, the authors are cautious about the certainty of this finding because too few of the studies they reviewed were of sufficiently high quality. They call for further research using more robust measures of physical activity.
Lead author Dr Amika Singh, of Amsterdam's Vrije Universiteit (VU) University Medical Center in the Netherlands, and colleagues carried out their review because of concerns that pressure to do well in academic tests could mean children are being denied time for exercise in favour of extra tuition time.
For their review they searched a number of reputable academic databases for studies that looked at the relationship between physical activity and academic performance and found 10 observational (that follow participants over a period of time), and four interventional studies that met their inclusion criteria.
For example, to be included in the review, the studies had to measure exposure to at least 1 measure of physical activity or fitness and assess the outcome of at least 1 academic performance or cognition measure, during childhood or adolescence.
12 of the studies included in the review were carried out in the US, one was in Canada, and one in South Africa.
The studies varied widely in size, from around 50 to around 12,000 participants, with ages ranging from 6 to 18 years and follow-up from as little as 8 weeks to over 5 years.
Singh and colleagues also rated the quality of the methods used on the studies: they found they ranged from 22% to 75%, with only two of them considered "high" quality.
They also noted that quality of methods was not very high when it came to reliability and validity of the measurement instruments.
For instance, none of the studies they reviewed used an objective measure of physical activity.
So, given these limitations:
"Based on the results of the best-evidence synthesis, we found evidence of a significant longitudinal positive relationship between physical activity and academic performance," they write.
They conclude that children who take part in physical activity appear to achieve better academic performance, but (and it is a big "but"):
"Because we found only 2 high-quality studies, future high-quality studies are needed to confirm our findings."
They recommend that such further research should "thoroughly examine" what happens to academic performance with each unit of increase in physical activity (what they refer to as a "dose-response relationship"). And it should also examine the explanations for the relationship, they note.