Exercise and Cognition: Research Updates

The positive effects of exercise on our bodies are widely known - improved muscular strength, weight management, balance, cardiovascular health, and reduced risk for some cancers and type 2 diabetes, just to name a few.  These measurable physical changes are often the focus of goals and intended outcomes for exercise.  An often overlooked advantage to exercise is the benefit that exercise may have on our minds - the most magnificent “muscle” of all.

Impairment of cognitive functioning in people with multiple sclerosis (MS) is estimated to occur in as many as 70% of individuals living with the disease (DeLuca, 2011; DeLuca 2015).  Cognitive impairments may include challenges with working memory, information processing, attention, concentration, as well as executive function tasks such as planning and prioritizing. (https://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms/Cognitive-Changes). 

Due to the high prevalence of cognitive impairment among people living with MS- and the profound impact these challenges can have in daily life- finding suitable strategies to assess, measure, and, most importantly, manage these issues has become a high priority for clinicians, researchers, and people living with MS.

Research among older adults demonstrated that consistent aerobic exercise over a 6-month period improved reaction time and executive function (Kramer, 1999).  Another study suggested that a combination of aerobic exercise and strength training had a more profound effect on cognition than aerobic exercise alone among older adults (Colcombe, 2003).  Contrary to popular belief, the effects of exercise on the brain were not related to blood flow, but are theorized to be related to preservation of brain tissue (Berchtold, 2002).  Brain Derived Neurotrophic Factor (BDNF), which has been shown to increase secondary to exercise-related muscle contraction (Wrann, 2013), affects areas[RK1]  of the brain responsible for cognition.  

All of this mounting evidence encouraged researchers to investigate whether a similar effect could occur among people with MS.  

Research suggests that aerobic exercise fitness levels correlate with improved aspects of cognitive function in people with more mild, relapsing disease – with treadmill exercise [RK2] having the most profound impact (Sandroff, 2015).  Progressive aerobic training was also associated with an increased level of cognitive processing speed, cardiopulmonary benefits, and potential increased connectivity and brain volume (per functional MRIs) in parts of the brain that influence cognition (Sandroff, 2016; Leavitt, 2014).

This evidence suggests that aerobic exercise training and fitness levels can have a positive influence on cognitive function.  Yet to be determined is the precise dosing of exercise required to encourage these positive changes in varying levels of the disease.  In the meantime, continue to explore exercise as an option that may not only influence your body in a positive way, but also your mind.

Berchtold NC, Kesslak JP, Cotman CW. Hippocampal brain-derived neurotrophic factor gene regulation by exercise and the medial septum. J Neurosci Res. 2002;68:511-521.

Colcombe S, Kramer AF. Fitness effects on the cognitive function of older adults: a meta-analytic study. Psychol Sci. 2003; 14:125-130.

DeLuca J, Nocentini U. Neuropsychological, medical and rehabilitative management of persons with multiple sclerosis. NeuroRehab. 2011; 29:197-219. 

DeLuca G, Yates RL, Beale H, Morrow SA. Cognitive impairment in multiple sclerosis: clinical, radiologic and pathologic insights. Brain Pathol. 2015; 25:79-98.

Kramer AF, Hahn S, Cohen NJ, et al. Ageing, fitness and neurocognitive function. Nature. 1999; 400:418-419. 128.

Leavitt VM, Cirnigliaro C, Cohen A, et al. Aerobic exercise increases hippocampal volume and improves memory in multiple sclerosis: preliminary findings. Neurocase. 2014;20:695-697

Sandroff BM, Balto JM, Klaren RE, Sommer SM, DeLuca J, Motl RW. Systematically-developed pilot randomized controlled trial of exercise and cognition in persons with multiple sclerosis. Presented at the 5th Conference of the International MS Cognition Society, June 23, 2016.

Sandroff BM, Hillman CH, Benedict RH, Motl RW. Acute effects of walking, cycling, and yoga exercise on cognition in persons with relapsing-remitting multiple sclerosis without impaired processing speed. J Clin Exp Neuropsychol. 2015;37:209-219.

Sandroff BM, Pilutti LA, Benedict RH, Motl RW. Association between physical fitness and cognitive function in multiple sclerosis: does disability status matter? Neurorehabil Neural Repair. 2015;29:214-223.

Wrann CD, White JP, Salogiannis J, et al. Exercise induces hippocampal BDNF through a PGC-1α/FNDC5 pathway. Cell Metab. 2013;18:649-659.