Feasibility and effects of remotely supervised aerobic training and resistance training in older adults with mild cognitive impairment: A pilot three-arm randomised controlled trial

Background Evidence on the effects of different exercise interventions on cognitive function is insufficient. Aims To evaluate the feasibility and effects of remotely supervised aerobic exercise (AE) and resistance exercise (RE) interventions in older adults with mild cognitive impairment (MCI). Methods This study is a 6-month pilot three-arm randomised controlled trial. Eligible participants (n=108) were recruited and randomised to the AE group, RE group or control (CON) group with a 1:1:1 ratio. Interventions were delivered at home with remote supervision. We evaluated participants' global cognition, memory, executive function, attention, physical activity levels, physical performance and muscle strength of limbs at baseline, 3 months (T1) and 6 months (T2) after randomisation. A linear mixed-effects model was adopted for data analyses after controlling for covariates. Tukey's method was used for adjusting for multiple comparisons. Sensitivity analyses were performed after excluding individuals with low compliance rates. Results 15 (13.89%) participants dropped out. The median compliance rates in the AE group and RE group were 67.31% and 93.27%, respectively. After adjusting for covariates, the scores of the Alzheimer's Disease Assessment Scale-Cognitive subscale in the AE group decreased by 2.04 (95% confidence interval (CI) -3.41 to -0.67, t=-2.94, p=0.004) and 1.53 (95% CI -2.88 to -0.17, t=-2.22, p=0.028) points more than those in the CON group at T1 and T2, respectively. The effects of AE were still significant at T1 (estimate=-1.70, 95% CI -3.20 to -0.21, t=-2.69, p=0.021), but lost statistical significance at T2 after adjusting for multiple comparisons. As for executive function, the Stroop time interference in the RE group decreased by 11.76 s (95% CI -21.62 to -1.90, t=-2.81, p=0.015) more than that in the AE group at T2 after Tukey's adjustment. No other significant effects on cognitive functions were found. Conclusions Both remotely supervised AE and RE programmes are feasible in older adults with MCI. AE has positive effects on global cognition, and RE improves executive function.