Antioxidants and physical exercise

The role of melatonin

Abstract

The evolution of life on earth has had to overcome adverse environmental conditions, mainly due to high atmosphere conditions of oxygen and presence of ultraviolet sun radiations. Both factors have a very dangerous oxidative effect, which can determine different molecular and structural cell damages. These circumstances promoted the appearance and development of defense antioxidant mechanisms, as the first barrier to assure the survival of the most primitive human beings and after as one of the principal harmonic and balanced functionality bases of the physiology of the different species on earth. On the other hand, need for movement and exercise have been a common stimulus during all the evolution process. However, although the regular practice of physical activity is one of the most recommended habits to combat the linked oxidative processes, among other, aging process, exercise means a greater metabolic use of oxygen, which finally promotes pro-oxidant responses. This duality in the oxidant responses (prooxidant/antioxidant) is based on the fact that each type of exercise (defined by its variables of intensity, duration, frequency, etc.) promotes different responses and adaptations on the oxygen metabolism. Melatonin is a hormone with different physiological functions, its antioxidant capacity being the most relevant in the field of physical exercise due to its potential beneficial effects.