A Multimodal Exercise Intervention Improves Cognitive Function In Older Adults

PURPOSE: To investigate the effects of a multimodal exercise intervention on cognitive performance and aerobic capacity, and whether these changes are associated with alterations in prefrontal cortex (PFC) oxygenation (O2Hb) among older adults. METHODS: Sixteen participants (M = 3, F = 13, age: 61.9 ± 4.1 years) were recruited from a local wellness club and completed a six-week multimodal exercise intervention three times per week. Participants completed a cognitive test battery (attention, processing speed, and executive function) and submaximal treadmill evaluation prior to and again upon completion of 18 individualized multimodal exercise sessions. Twelve participants (M = 3, F = 9, age: 63.1 ± 4.0 years) also completed a three month follow up evaluation. A functional near-infrared spectroscopy (fNIRS) device was used to measure left and right prefrontal cortex (LPFC and RPFC) oxyhemoglobin (O2Hb) during the cognitive evaluation. A repeated measures one-way ANOVA was used to determine pre-, post- and three-month post differences in cognitive performance scores, aerobic capacity and PFC O2Hb. RESULTS: Participants showed an improvement in cardiorespiratory fitness (+5.9 ml/kg/min (estimated VO2max) and this remained 6.3 ml/kg/min higher than pre-testing at the three-month post time point. All three cognitive constructs improved significantly following the 6-week exercise intervention while executive function also remained elevated at the three-month post-testing time point (attention-pre: 42 ± 8, post: 49 ± 11, processing speed-pre: 51 ± 16, post: 60 ± 12, executive functioning-pre: 54 ± 12, post: 60 ± 13, 3-mont post: 63 ± 15). The RPFC and LPFC displayed no significant changes in O2Hb. A significant negative association between changes in aerobic capacity and RPFC O2Hb during the processing speed test (r: -0.51, p: 0.042) was detected. In addition, significant negative associations between aerobic capacity and LPFC O2Hb during the processing speed (r: -0.60, p: 0.015) and executive function (r: -0.62, p: 0.011) tests were detected. CONCLUSIONS: A 6-week multimodal exercise program can improve cognitive performance in older adults. The negative associations between estimated maximal aerobic capacity and changes in PFC O2Hb suggests an improved neural efficiency with increased aerobic fitness.