The Effect of a Single Bout of Aerobic Training at Different Intensities on Learning and Long-Term Memory Processes in Young Adults with ADHD

Background: Several researchers have examined the effect of physical activity (PA) on cognitive functions among participants with attention deficit hyperactivity disorder (ADHD), with only a few directly assessing its effects on learning or on long-term memory. The intensity of PA as a factor in changing cognitive function was recently addressed by participants without ADHD.

Aim: To examine the effects of a single bout of low intensity vs. medium-high intensity aerobic exercise on the learning process of declarative memory for facts in young adults with ADHD.

Methods: 28 physically active young adults with ADHD (age = 25±2.3 yr) performed nine appointments in three conditions: a single bout of low intensity aerobic exercise, a single bout of medium-high intensity aerobic exercise, or control condition (watching a silent film) for 25 min, which was followed by an exam about one of three subjects: dolphins, the Chinese zodiac, or chocolate. Then they were presented with an informative video about the subject, and examined on it. Twenty-four hours and two weeks later, they performed two more exams about the subject. In the second and third phases they were presented and examined about the second and third informative videos in the second and third conditions. The assignment of the order of conditions and the video for learning in each of the phases was random.

Results: In general, in all three conditions, there was a significant decrease in the total score between the test performed immediately following the exposure to the video and the tests that took place 24 hours and two weeks later (F2,54=47.36, p.01). However, participants had a significantly higher score 24 hours following exposure to the video in both the low intensity and the medium-high intensity condition phases in comparison to their performance 24 hours following exposure to the informative video in the control condition phase (F2,54=6.14, p.01). In addition, two weeks following exposure to the video, participants had a significantly higher score in the medium-high intensity condition phase in comparison to the control condition phase (F2,54=3.1, p.05).

Discussion: The results of the study show that a single bout of PA comprising 25 minutes of low or medium-high aerobic exercises had a clear advantage in the ability of participants with ADHD to retain information from an instructional video presented after the PA intervention. Importantly, the most robust effect of the PA was on performance at 24 hours and at two weeks post-training.

Conclusion: The present findings point to a positive effect of low to high aerobic exercises on retaining declarative long-term memory for young adults with ADHD. Based upon this, these findings could be used to encourage young adults with ADHD to perform aerobic exercises prior to learning new declarative information.