In the article “Effect of Exercise Training on Hippocampal Volume in Humans: A Pilot Study,” Beth Parker, Paul Thompson, Kathryn Jordan, Adam Grimaldi, Michal Assaf, et al. (2011) perform a preliminary study studying “the direct effect of supervised exercise training on MRI estimates of hippocampal volume in healthy humans” (p. 585). The hypothesis utilized by the researchers was that “exercise training increases hippocampal volume” (Parker et al. 2011, p. 588).
For this study, thirteen men and women – all healthy, nonsmoking adults between 23-45 years of age with no exercise or chronic diseases – were utilized, which is a comparatively small sample size. While the criteria was adequately considered in cultivating this sample, the small sample size makes their findings somewhat insignificant from a statistical standpoint. Furthermore, the authors admit that their inclusion of both men and women in the sample, and their lack of a control group, makes their findings unverifiable due to the difference in hormones between the sexes (Parker et al. 2011, p. 591).
The independent variable in this study was the presence of supervised exercise training; this was defined as cardiovascular activity including walking and running on a treadmill. The variable was measured with a metabolic cart for maximal oxygen uptake during exercise. The dependent variable was hippocampal volume, which was assessed with hand-drawn ROI analysis.
For this study, a preliminary study was used, which may not have been appropriate for this kind of research if proper findings were desired. Preliminary studies are simply an initial exploration of issues leading up to a more proper evaluation under stricter conditions; while it is perfectly valid as an exploratory study, its findings are inherently flawed due to the comparative lack of rigor a full study would contain. As such, it is difficult to truly evaluate how seriously to take its findings as well-supported research.
Since this study was a preliminary one, the researchers did not take many obvious measures to control potential problems. The use of an exercise trainer to evaluate the participants’ activity allowed them to control for the same level of progress in all participants so they could best record their results.
According to the study, the researchers found that hippocampal volumes increase steadily after 10 weeks of consistent cardiorespiratory exercise and the resulting increases in cardio fitness. This study has provided further incentive to research this particular subject, as the possibility exists for positive results.
References
Parker, B. A., Thompson, P. D., Jordan, K. C., Grimaldi, A. S., Assaf, M., Jagannathan, K., &
Pearlson, G. D. (2011). Effect of exercise training on hippocampal volume in humans: A pilot study. Research Quarterly for Exercise and Sport, 82(3), 585-91.
