The effect of medium term physical activity interventions on cognitive function and indices of cardiovascular health in overweight and obese adults

The cumulative effect of obesity with a sedentary/low-active lifestyle at mid-life places individuals at elevated risk for obesity-associated comorbidities and accelerated cognitive decline in later life. There is a paucity of research examining the relationship between physical activity (PA) and cognitive function in middle-aged obese adults, further confounded by a lack of objective measurement of PA. Study 1 (n=63) aimed to examine the relationship between objectively measured physical activity with multiple cognitive test outcomes in a sample of low-active, overweight/obese, middle-aged adults. The findings indicated that IQ and age were the greatest predictors of cognitive function, with small contribution from PA and body composition. Increased physical activity and/or cardiorespiratory fitness (CRF) translates to improved cognitive function in non-obese adults, yet this has largely been unexplored in overweight/obese adults. It is not known what aspects of exercise (volume or intensity) yield optimal improvements, or the physiological adaptations that are required to translate to cognitive change. Study 2 (n=28) aimed to compare the impact of 12-weeks high-intensity exercise regimes (interval and continuous) on indices of cardiovascular fitness and cognitive function in middle-aged, overweight/obese females relative to a no-exercise control group. The findings suggest equivalent improvement in CRF between groups, and a favourable effect of training following INT for a limited number of cognitive outcomes (executive function and spatial memory). Study 3 (n=33) aimed to examine the impact of increasing habitual activity through pedometer “step-count” targets over 12-weeks on indices of cardiometabolic health and cognitive function. Findings indicate that post-intervention step count was associated favourably with indices of executive function, verbal and spatial memory. Taken together these studies found a limited number of exercise associated improvements, predominantly in executive function and spatial working memory.