Effects of multidomain lifestyle intervention, omega-3 supplementation or their combination on physical activity levels in older adults: secondary analysis of the Multidomain Alzheimer Preventive Trial (MAPT) randomised controlled trial.

Background/objectives: to investigate the effects of a 3-year multidomain lifestyle intervention, omega-3 supplementation or both on physical activity (PA) in older adults with subjective memory complaints.

Design/settings/subjects: the Multidomain Alzheimer Preventive Trial was a 3-year randomised controlled trial that enroled 1,680 community-dwelling adults aged 70 years or over, with subjective memory complaints. Participants were randomised to omega-3 supplementation (total daily dose of 800 mg docosahexanoic acid and up to 225 mg eicosapentanoic acid), multidomain intervention (nutritional and exercise counselling and cognitive training), omega-3 plus multidomain intervention or placebo with usual care.

Methods: PA was assessed using a self-reported questionnaire. From this, global moderate-to-vigorous PA, leisure-time PA, non-leisure-time PA and light PA were measured in metabolic equivalent tasks-minutes per week (MET-min/week).

Results: in the multidomain groups, participants significantly increased their moderate-to-vigorous and leisure-time PA at 6 months (≥300 MET-min/week for both in the multidomain groups; P ≤ 0.002) before returning to baseline by the end of the trial. Activity in the placebo/usual care and omega-3/usual care groups declined overtime. Between-group differences remained significant for both multidomain groups for leisure-time physical activity at 2- and 3-year follow-ups. Compared to placebo/usual care, interventions had no significant effects on non-leisure-time PA and light PA. Omega-3 supplementation alone had no effects on PA.

Conclusions: a multidomain intervention focused on cognitive training, and nutritional and PA counselling increased PA in the short-term and limited its decline in the long-term among older adults with memory complaints. ClinicalTrials.gov-Registration number: NCT0067268.