Joggin’ the Noggin: Towards a Physiological Understanding of Exercise-Induced Cognitive Benefits

Abstract

This narrative review examines literature pertaining to possible physiological explanations for observed cognitive benefits stemming from improvements to cardiovascular fitness following chronic aerobic exercise. Studies regarding exercise and cardiovascular fitness, angiogenesis, neuroinflammation in relation to IGF-1 signalling, regulation of neurotrophins, neurogenesis and plasticity, cognitive training, are briefly described. We propose that current evidence points towards a mechanism by which cardiovascular fitness improvements act to promote long-term angiogenesis and cerebral circulation. This important adaptation allows for increased delivery and upregulation of neurotrophins along with supporting factors to the brain, particularly to the hippocampal neurogenic niche, following acute exercise bouts. We propose a sequential timeline and approximate time scale for this mechanism, describing how these stages generate increased support for neurogenesis and brain plasticity in combination with cognitive training to provide long-term cognitive benefits and protection against age-related cognitive decline. Influences from age, gender and other variables are considered, and methodological factors that could be utilised in future studies to further clarify the proposed model are discussed.

Physical fitness and physical activity association with cognitive function and quality of life: baseline cross-sectional analysis of the PREDIMED-Plus trial

“…In this regard, physical fitness (PF) needs to be considered. PF is a measure of physical condition and well-being, and it has been reported that PA with an effective improvement in cardiovascular fitness has a greater effect on cognitive function than PA focused on strength 26 . We aimed to investigate the relationship between PA and PF with cognitive function and quality of life, independently of the impact of the adherence to an energy-restricted MedDiet, using baseline data from the PREDIMED-Plus trial 27 .…”

Paradoxical effects of exercise on hippocampal plasticity and cognition in mice with a heterozygous null mutation in the serotonin transporter gene

“…At first glance, our behavioural results are somewhat surprising, as a substantial body of clinical and preclinical literature has established positive behavioural effects of exercise in both WT mice and transgenic mouse models Stimpson et al, 2018;Suo et al, 2016). Furthermore, extensive research has established CA1 LTP and neurogenesis as candidate mechanisms underpinning enhanced cognitive functioning in WT and transgenic mice following exercise (Ohline & Abraham, 2018;Patten et al, 2015).…”

“…In rodents, the G × E interaction approach has been more successful due to experimental control over the environment (Nithianantharajah & Hannan, 2006). Voluntary physical activity (exercise) has been found to improve cognition in human and animal models (Stimpson, Davison, & Javadi, 2018;Suo et al, 2016). Additionally, exercise is known to enhance hippocampal synaptic plasticity and adult neurogenesis, although the precise mechanisms remain unclear (Ohline & Abraham, 2018;Patten et al, 2015).…”

A prospective study of focal brain atrophy, mobility and fitness

“…Although the brain structure deteriorates in ageing with the prefrontal and medial temporal lobes being the most vulnerable areas , there is some evidence that maintaining fitness help counteract the functional effect of brain ageing. Potential mechanisms for this association are supported by animal studies and include exercise‐induced neurogenesis, endothelial cell proliferation, vascularization, neurotransmitters and neurotrophic factors . Whether maintaining fitness counteracts brain ageing in community‐dwelling older adults remains unclear because of the limited availability of longitudinal studies adequate to test this hypothesis.…”