Compared with exercising inside, performing equivalent exercises outside may have additional cognitive benefits, according to the results of a study published in Scientific Reports.
Students (N=30) were recruited from the University of Victoria in Canada. Participants completed an iPad-based oddball task while wearing a 2016 Muse electroencephalography (EEG) device prior to and after a 15-minute walk intervention. Walks were performed indoors or outdoors an average of 2 days apart at standardized times of the day. Postwalk changes in EEG data were compared between indoor and outdoor walks.
The mean age of study participants was 21 (95% CI, 20, 22) years, and 21 were women.
When performing oddball tasks inside, the mean pre- and postwalk reaction times were 220.1 ms and 218.1 ms, the mean numbers of errors made were 0.8 and 1.2, and the mean P300 amplitudes were 1.5 µV and 1.6 µV, respectively. When performing these tasks outside, the mean pre- and postwalk reaction times were 221.0 ms and 213.3 ms, the mean numbers of errors made were 1.3 and 0.7, and the mean P300 amplitudes were 1.4 µV and 2.4 µV, respectively.
For reaction times, walking location did not have a significant effect (P >.05). There was a significant main effect for time (F[1,29], 11.01; P =.002), and the interaction between time and location tended toward significance (F[1,29], 3.95; P =.05). Reaction time decreased following the indoor (t, 5.07; P =0.000) walk but not the outdoor (t, 0.84; P =.409) walk.
There was no significant change in accuracy during the study (F[1,29], 3.59; P >.05).
The P300 amplitude had a significant time main effect (F[1,29], 12.40; P =.001), as well as a time-by-location interaction (F[1,29], 5.62; P =.025). Contrary to the change in reaction time, there was no change in amplitude following the indoor walk (t, 0.23; P =.82); however, a significant increase in amplitude was noted after the outdoor walk (t, 4.49; P <.001).
The limitations of this study included its small sample size, the lack of an exercise intensity assessment, and the age of the study participants.
Study authors concluded, “We demonstrate that a brief walk outside results in a greater increase in cognitive function than a short walk inside. Given the continued growth in urbanization and a move to an indoor lifestyle, our results highlight the importance of spending time in nature, especially when exercising. Indeed, in a world where many people hit the gym before or after work or on their lunch break, our results suggest that these people would be better served by simply getting outside.”
Boere K, Lloyd K, Binsted G, Krigolson OE. Exercising is good for the brain but exercising outside is potentially better. Sci Rep. 2023;13(1):1140. doi:10.1038/s41598-022-26093-2