ABSTRACT
The world today is facing an increasing number of individuals with lifestyle related diseases such as cardiovascular diseases (CVD), type 2 diabetes and certain types of cancers (Lee et al., 2012). This has tremendous consequences both at the individual and the societal level in terms of decreased quality of life, increased morbidity and mortality (Lee et al., 2012). The economic burden on the health care system and lost productivity adds to the burden of the society. The reason for this increase is multifactorial but lack of physical activity, and excess body fat contribute (Grontved et al., 2012; Grontved and Hu, 2011; Tang-Peronard et al., 2011). Recent research has shown that physical activity and high aerobic fitness (VO2peak) level are associated not only with insulin sensitivity, obesity and other metabolic risk factors, but also with improved cognitive function in relation to biological markers (brain derived neurotrophic factor, BDNF), and cognitive tests (Aberg et al., 2009). Furthermore, it has been found that BDNF is closely associated with the metabolic risk factors (Tyler et al., 2002; Krabbe et al., 2007). These apparently very different parameters, obesity, physical activity, fitness and cognitive function, seem to be interlinked. Associations between physical activity, fitness, obesity and CVD risk factors such as insulin resistance are well known, while knowledge of the association between the physical activity and cognitive function and biological mechanisms behind this association is increasing fast.
