The effects of a single bout of high-intense strength exercise on cognitive function and postural dual-task control in older adults

In this study we aimed to test if acute strength exercise would induce cognitive improvements. Secondarily, we examined the relationship between exercise-induced changes in cognitive function and postural dual-task control. Thirty-seven cognitively intact, non-faller older adults (=60 years) were nonrandomly allocated to strength exercise or control. Strength exercise consisted of Smith machine squats (one session, 3 × 3reps at 90%, 95%, and 100% one-repetition maximum). Control participants held seated rest for 45 min. Cognitive functions, recognition (memory search), working memory (mathematical processing), processing speed (2-choice reaction time), and postural dual-task control were tested before and immediately after exercise or control using the Automated Neuropsychological Assessment Metrics-4 (ANAM4) battery and a mathematical counting task while maintaining a tandem Romberg stance with eyes open on a force plate. Outcome measures were response time and performance index (100 × [accuracy/response time]) on the ANAM4 tests and sway activity and entropy during the postural dual-task. We found a non-significant improvement with moderate effect size in performance index on the mathematical processing task of experimental participants compared to control participants (p = 0.145, (Formula presented.) = 0.060). Improvements in the mathematical processing task over time in the control group were associated with increased sway activity during the postural dual-task. No significant associations were found between changes in cognitive function and changes in postural control in the experimental group. Ultimately, our results may direct researchers and healthcare professionals in designing the optimal exercise treatment to improve cognitive function and postural control in older adults.