Dose-response relationship of high-intensity training on global cognition in older adults with mild cognitive impairment or dementia: a systematic review with meta-analysis - the ACHIEVE-Study

The prevalence of mild cognitive impairment (MCI) and its subsequent progression to dementia has increased progression to dementia has increased worldwide, making it a topic of interest. of interest, and it has been observed that approximately 23% of cases are avoidable through preventable through vigorous exercise. A systematic review with meta-analysis was conducted by searching in the PubMed, Scopus, CINAHL, and Web of Science databases. For inclusion, studies had to incorporate High Intensity Training (HIT) as a primary or significant component of the overall intervention for older adults with MCI. Out of the 611 articles identified, 14 randomized clinical trials met the criteria for inclusion in the review. Fourteen trials were included in the systematic review, and seven were included in the meta-analysis. A total of 1839 participants were included in the studies, with 1014 receiving a high-intensity training-based intervention, and 998 were considered in the meta-analysis. Compared to usual care or sedentary activities, the high-intensity training interventions had a positive effect on cognition, either improving it or delaying the decline (g = 0.710 (95% CI: 0.191 — 1.229; p = 0.007). Additionally, the meta-analysis determined that a frequency of 3 sessions per week (g = 0.964, CI = 0.091 — 1.837, p = 0.030) of approximately 60 minutes (g = 0.756, CI = 0.052 — 1.460, p = 0.035) each was the best dose to obtain better effects on global cognition. Low-frequency and short-duration high-intensity training interventions are sufficient to improve or at least delay the decline in global cognition.