Aerobic exercise has been positively linked to brain functioning and structure in a variety of cases, one of which has been neurogenesis in the hippocampus, an area of the brain important in learning. Despite this, it has remained unclear as to the types of aerobic exercise that are the most beneficial for neurogenesis as well as the effect of individual genetic variation on responses to exercise. New research from the University of Jyväskylä (Finland) however has sought to investigate these unanswered questions.
In the study, which will be published soon in the Journal of Physiology, the team compared the effects of sustained running exercise, high-intensity interval training (HIT) and resistance training on adult hippocampal neurogenesis in adult male rats. Three rat lines were used, including the common Sprague-Dawley rats and two lines specially developed by collaborators at the University of Michigan (MI, USA). These rats were developed with either a genetically high response to aerobic training (HRT) or a low response to aerobic training (LRT).
The rats were enrolled into a training regime of either running, HIT or resistance training for a period lasting 6–8 weeks. Controls of the same line remained in sedentary conditions.
Results of the study indicated that the highest number of new hippocampal neurons was observed in rats that ran long distances with a predisposition to respond to aerobic exercise (HRT). HRT rats that voluntarily ran on a wheel had 2–3 times more hippocampal neurons at the end of the training period in comparison to sedentary controls.
In contrast to the results for sustained running, HIT exhibited minor increases in hippocampal neurogenesis and resistance training had no recorded effect.
The indication that sustained aerobic exercise was the only exercise type that successfully contributed to hippocampal neurogenesis in adult rats provides important information for improving learning and potentially other functions within the brain.