Effects of two different intensities of aerobic exercise on elderly people with mild cognitive impairment: a randomized pilot study

Objective: To evaluate the effect of different intensities of aerobic exercise on elderly people with mild cognitive impairment. Design: A randomized trial. Setting: Residential care homes for elderly people. Subjects: Forty-eight patients were included in the study. Interventions: The patients were randomized in three groups. Group A performed aerobic exercise at 40% of heart rate reserve, group B did the same at 60% and group C carried out recreational activities. The duration of the study was three months. Main measures: Cognitive level and functional ability were assessed by means of the Mini Mental State Examination and the Timed Up and Go test before the intervention, at the end of it and three months later as a follow-up. Results: After completion of the aerobic training programme, the patients' Mini Mental State Examination scores improved marginally (group A from 19.8 +/- 5.1 to 20.6 +/- 7.3; group B from 20.8 +/- 4.6 to 21 +/- 5.4). A similar trend was observed for the Timed Up and Go test scores (group A from 18.8 +/- 5.3 to 18.5 +/- 5 seconds; group B from 15.4 +/- 4.2 to 14.3 +/- 5.1 seconds). However, no statistically significant differences were found at any time during the evaluation regarding cognitive level and functional autonomy among the three groups. Conclusion: In this pilot study, intensity does not seem to be a determining factor when aerobic exercise is performed by people with mild cognitive impairment.