Exercise-Induced Biological and Psychological Changes in Overweight and Obese Individuals: A Review of Recent Evidence

On a global scale, the most recent evidence indicates that over 400 million adults are obese while ~20 million children and 1.6 billion adults are overweight. The World Health Organization reveals that, by the year 2015, ~2.3 billion adults will be overweight and more than 700 million will be obese. In this review paper we summarized the current evidence to elucidate the impact of exercise training on biological and psychological health indices in overweight and obese individuals. Endocrine function indices that are discussed herein include leptin, adiponectin, growth hormone, and ghrelin levels. Psychological factors include anxiety and depression, body image, and motivation for exercise. Overall, exercise promotes physical and psychological health in overweight and obese individuals particularly because exercise-induced adaptations occur across a multitude of systems within the active human. The impact of exercise on specific biological and psychological health indices contributes to overall health in overweight and obese individuals. 1. Introduction Increased adiposity and physical inactivity have been identified as harmful health indices [1]. It has been widely acknowledged that obesity leads to health problems such as cardiovascular disease, type 2 diabetes, and hypertension [2, 3]. On a global scale, the most recent evidence indicated that over 400 million adults are obese while ~20 million children and 1.6 billion adults are overweight [2]. An unpleasant estimation by the World Health Organization revealed that by the year 2015 ~2.3 billion adults will be overweight and more than 700 million will be obese [2]. Thus, it is necessary to establish practical/cost effective strategies as well as update and renew current health initiatives, such as physical activity participation, that will lessen the risk of weight gain and disease in overweight and obese populations. It is well known that physical activity contributes, at least in part, to a healthy quality of life [4]. Indeed, compelling evidence supports that cardiorespiratory fitness (an objective measure of habitual physical activity) is an independent predictor of all-cause and cardiovascular disease mortality [5]. Specifically, recent evidence indicates that individuals with the highest level of physical activity had a greater total life expectancy compared to individuals with low physical activity participation [6, 7]. Conversely, physical inactivity has been linked to a plethora of health conditions such as type 2 diabetes [2] and has been identified as a greater risk for morbidity and