Scientific Background


Given the role that physical activity has assumed in medical research, neuroscience and psychology it is not a surprise that the World Health Organization has repeatedly pointed out the importance of sport and exercise.  The UN agency intervened in this field promoting cancer prevention and to underline the positive relationship established between nutrition, sport and the environment (McMichael, 2008). The WHO was back on the subject in 2016  (Ministero della Salute, 2016), indicating a minimum amount of weekly time to devote to sport or exercise as a general prevention factor. In fact, the reduction of physical inactivity has been included among the nine objectives of the global plan for the prevention of non-transmissible diseases  (Organizzazione Mondiale della Sanità, 2012).


The indications given by the WHO refer to a wide range of publications and knowledge acquired from international research. Particularly noteworthy are the progress achieved in the identification of the molecular mechanisms that regulate the positive interaction between sport and health: in a recent meta-analysis published in Cellular Physiology and Biochemistry the research team of L. Masi examines the capacity of the exercise Physical to intervene in the control mechanisms that regulate genetic expression, demonstrating how the action of physical activity on microRNAs presides over the epigenetic process in various ways (Masi, et al., 2016).  
Matsui et al. (2011) identified over-compensation of glycogen in the astrocytes of the CNS glia at the end of a training session. This finding makes it possible to correlate the training and restructuring of the cerebral metabolism, which is fundamental for the modification of the synaptic force and the structural strengthening of the cerebral circuits.
While physical inactivity is one of the first causes of chronic diseases of the modern age 
  (Booth, Roberts, & Laye, 2012), lexercise has also been proposed as a potential treatment of drug addiction, depending on the role that it is involved in modulating the neurotransmission system of biogenic amines and glutamate. The use of drugs, acting through epigenetic mechanisms controlled by neurotrophic factors such as BDNF, talters the functioning of these circuits, while specific training protocols are able to reverse this effect (Lynch, Peterson, Sanchez, Abel, & Smith, 2013).


Another line of research investigates the neurophysiological component of the influence of physical exercise on psychological abilities and functions. Smith et al. (2010) evaluated for the National Institutes of Health twenty-nine studies carried out according to the RCT criteria on a total of over two thousand participants, agreeing that physical activity increases the expression of BDNF neurotrophic factors both in the hippocampus and in the peri-hippocampal regions. Further evidences of this link have been identified in the dentate gyrus of the hippocampus, associated with the mnemonic and attentive performance (Pereira, et al., 2007).         
 (Suo, et al., 2016) have shown that training is significantly related to the increase in the thickness of gray matter in the posterior cingulate cortex, with a consequent increase in general cognitive faculties. 
Exercise also affects the activity of AMPK in different tissues, including the hypothalamus. AMPK is an enzyme that regulates cellular homeostasis by controlling the metabolic mechanisms of ATP hydrolysis. During the sport activity the AMPK sets in motion processes able to increase the production of ATP, thus increasing the energy resources of the SNC. In the central nervous system, AMPK also regulates the production of insulin and leptin, with important implications for eating behavior and synaptic functioning  (Richter & Ruderman, 2009).