Leptin and exercise: an update

Leptin is a multifunctional hormone (adipocytokine) involves in several biological processes. From brain metabolism, to signalling, in sexual development, inflammation, fat metabolism, as an ergogenic aid for sport and in the regulation of food intake and body weight. However, recent studies investigated some new aspects of leptin, elucidating the genetics mechanisms of production, relationships with starvation and environmental variables, and even some methodological issues in leptin measurement. Some interesting new studies deals with aerospace medicine, investigating effect of space flights on leptin. Relationships with rare disease such as HIV and with psychiatric disorders are also among the recent development of leptin studies. Physical activity remain the most important factor associate with leptin metabolism, and recent studies shows how the leptin levels are influenced by exercise in extreme sport, such ultramarathon. Relationships between leptin levels and amount of exercise is well known, but still exist some controversial point about what is the shape of the relationships (if linear or polynomial) between leptin and moderate and heavy exercise. It is emerging the need for multifactorial studies which take into account phenotype, environmental variables, nutritional status, as well as cultural aspects influencing nutrition, and controlled timing in leptin measurements.