Influence of the timing of brief, high-intensity cycling exercise on memory for novel words presented during an initial Portuguese lesson among older adolescents with ADHD: An exploratory study.

This exploratory study examined whether brief high-intensity cycling exercise, performed either before or after a single online Portuguese language lesson, improved language acquisition or retention in older adolescents with ADHD, compared to a resting control condition. Participants (n = 29; mean age 19.2; no prior Portuguese knowledge) were randomly assigned to one of the three conditions: control, exercise before, and exercise after. The 29-minute Portuguese lesson introduced vocabulary, grammar, and syntax. Immediate learning (Day 1) and retention (Day 7) were assessed through sentence production, free recall, and recognition memory. The exercise groups completed three 30-second leg cycling sprints with active recovery. The language lesson and assessments were identical across conditions. Although no statistically significant differences were found, effect size analyses revealed that exercising before the lesson was associated with moderately better recognition memory on both Day 1 (d = 0.51) and Day 7 (d = 0.77), along with small improvements in free recall (d = 0.21 to 0.44). In contrast, exercising after the lesson was linked to worse recognition memory (d = -0.51) and fewer sentences created (d = -0.69 to -0.99) compared to control. The findings from this exploratory study show that in a sample of older adolescents with ADHD the brief, intense cycling exercise prior to an initial Portuguese lesson was associated with a pattern suggesting higher free-recall and recognition memory for Portuguese words, while the similar exercise performed after the language lesson was associated with a pattern suggesting worse memory performance on sentence production, a more complex cognitive task. Further research with larger and more diverse samples is needed to confirm the present findings and clarify optimal exercise timing during the initial and subsequent days of second language learning.