Ghrelin Behavior in Exercise and Training

Ghrelin is a peptide hormone that consists of 28 amino acids and is secreted from the Epsilon cells of the pancreas, a recent peptide hormone that is linked to the secretion of the Growth Hormone (GH) and the regulation of energy homeostasis and insulin. Because physical activities and exercise cause loss of energy balance and are a stimulant for GH secretion, the behavior of ghrelin has attracted the attention of many sports practitioners in relation to physical activity. In this paper, we have tried to introduce this peptide, its behavior and effect on long-term aerobic training, short-term aerobic training, and resistance training based on the review of research in this field. The articles have been collected in English and Persian from the Science Direct, PubMed, Scopus, Web of Science, Springer, Google Scholar, SID databases and in a range of years (1996 to 2019). Exercise and physical activity, as a stress that disturbs the body's energy balance, can have different effects, depending on their nature, so that long-term exercises can result in adaptation and short-term exercises cause acute responses, so that they are different. However, research is still ongoing in light of future needs and contradictory outcomes.