Therapeutically relevant structural and functional mechanisms triggered by physical and cognitive exercise

Abstract

Physical and cognitive exercise may prevent or delay dementia in later life but the neural mechanisms underlying these therapeutic benefits are largely unknown. We examined structural and functional magnetic resonance imaging (MRI) brain changes after 6 months of progressive resistance training (PRT), computerized cognitive training (CCT) or combined intervention. A total of 100 older individuals (68 females, average age=70.1, s.d.±6.7, 55–87 years) with dementia prodrome mild cognitive impairment were recruited in the SMART (Study of Mental Activity and Resistance Training) Trial. Participants were randomly assigned into four intervention groups: PRT+CCT, PRT+SHAM CCT, CCT+SHAM PRT and double SHAM. Multimodal MRI was conducted at baseline and at 6 months of follow-up (immediately after training) to measure structural and spontaneous functional changes in the brain, with a focus on the hippocampus and posterior cingulate regions. Participants' cognitive changes were also assessed before and after training. We found that PRT but not CCT significantly improved global cognition (F(90)=4.1, P<0.05) as well as expanded gray matter in the posterior cingulate (Pcorrected <0.05), and these changes were related to each other (r=0.25, P=0.03). PRT also reversed progression of white matter hyperintensities, a biomarker of cerebrovascular disease, in several brain areas. In contrast, CCT but not PRT attenuated decline in overall memory performance (F(90)=5.7, P<0.02), mediated by enhanced functional connectivity between the hippocampus and superior frontal cortex. Our findings indicate that physical and cognitive training depend on discrete neuronal mechanisms for their therapeutic efficacy, information that may help develop targeted lifestyle-based preventative strategies.

Physical activity level in people with age related white matter changes correlates to better motor performance, lower comorbidity and higher cognitive level

“…Furthermore, cardiorespiratory fitness affects white-matter integrity [8, 9], which may consequently have positive effects on functional brain activity in old age [10]. …”

Associations between handgrip strength and mild cognitive impairment in middle‐aged and older adults in six low‐ and middle‐income countries

“…Evidence indicates that serum 25-hydroxyvitamin D (25(OH)D) may impact brain health 54 as epidemiological evidence supports associations between low serum 25(OH)D concentrations and poorer cognitive performance in community-dwelling older populations 55. The beneficial effects of resistance training may be mediated through exercise-induced increases in grey matter and attenuation of aging-related white matter abnormalities 60. However, longitudinal and interventional studies are needed to confirm or refute the vitamin D deficiency hypothesis.Beyond considering grip strength as a marker of cognitive and functional capacities, further work should also investigate how increasing muscular fitness may be a therapeutic target for improving cognitive and functional outcomes of those with MCI in LMICs.…”

The Roles of Exercise and Yoga in Ameliorating Depression as a Risk Factor for Cognitive Decline

“…In arguably one of the most comprehensive studies to date, Suo et al found that, among 100 older individuals (mean age 70.1 years) with MCI, six months of progressive resistance training but not computerised cognitive training significantly improved global cognition [44]. Interestingly, the computerised cognitive training program but not the exercise intervention attenuated decline in overall memory performance.…”