Improving executive function: Does the intensity of a single bout of aerobic exercise matter?

A single bout of moderate-to-heavy intensity aerobic exercise benefits executive function. Here, we examined whether "very light" and "light" intensity aerobic exercise provide a benefit to executive function similar to "moderate" intensity. A cross-over counterbalanced design (N=11; seven female, age range = 19 – 27 years of age) was employed and prior to our intervention participants completed a VO2peak to quantify lactate threshold (LT). Subsequently, three separate sessions – completed on separate days – entailed 10-min of "very light", "light" and "moderate" intensity aerobic exercise (via cycle ergometer) quantified as 0%, 40% and 80% of LT, respectively. Prior to, and immediately following, each exercise intervention participants completed an oculomotor assessment involving antisaccades (i.e., saccade mirror-symmetrical to a target). Antisaccades are an executive task that provide an ideal tool for examining postexercise changes to executive function. Results showed a 24 ms and 14 ms postexercise reaction time (RT) for moderate (p=0.019, d=0.841) and light (p = 0.004, d=1.121). In contrast, pre- and postexercise RTs for the very light intensity, did not reliably differ (p = 0.381, d=0.277). Accordingly, we propose that a "light" intensity represents the lower-bound work rate by which a single bout of exercise benefits executive function.