Acute augmenting influences of exercise on the working memory estimated by 2-back method in young adults

We conducted the 2-back test on 15 young student volunteers in order to investigate the effects of different loads of exercise on the working memory. Subjects exercised 10 min. on an ergometer cycle with loads in such a way that their heart rate attained 10, 30, or 60% of the predicted maximal heart rate (HRmax). The experiment consisted of a pre-2-back test, then exercise and then a post-2-back test with the intervals between experiments longer than one day apart. The order of exercise was distributed evenly among subjects. The 2-back test consisted of showing one three-lettered card after another on a PC screen with a given time interval to each subject. Three letters of every card were chosen randomly from a 71 letter pool which consisted of 26 English alphabetical letters and 45-Japanese syllabary ones so that the three-letter composition was meaningless and had a rather low probability for the subject to guess the composition as well. They were then asked to answer the exact lettered serial sequencing presented on the screen two back for five minutes. Mean results of the 2-back test after each exercise was compared with that before exercise using a dually tailed t test. After 10, 30 and 60% exercise, the results were significantly augmented (p=0.01, p=0.002 and 0.00003, respectively). Present results suggest that exercise could have activating influences on the cognitive power in young normal humans. [Jpn J Physiol 55 Suppl:S183 (2005)]