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Revista Brasileira de Medicina do Esporte
On-line version ISSN 1806-9940
BACK, Flávio Augustino et al. Non-photic synchronization: the effect of aerobic physical exercise. Rev Bras Med Esporte [online]. 2007, vol.13, n.2, pp. 138-142. ISSN 1806-9940. http://dx.doi.org/10.1590/S1517-86922007000200014.
The main alterations, either acute or chronic, caused by aerobic physical exercise (PE) over the body are generally well-known. However, there is a particular effect of PE which started to be elucidated in the beginning of the 90's in humans which has the capacity to alter the temporal relationship of the body with the environment. The modification of the expression of the circadian rhythms caused by PE qualifies it as a synchronizer of the biological oscillators. The main synchronizer of the biological rhythm is the light/dark geophysical cycle. The day/night rotation which occurs through differences in the luminosity levels is perceived through photic ways by the CTS. These stimuli, called photic, provide temporal information to the CTS synchronizing hence the biological oscillators to this environmental cycle. Other stimuli are also capable to synchronize them and are called non-photic synchronizers. This review writes about the effect of PE over the temporization system as well as discusses the possible and probable chronobiological applications of the mentioned knowledge. PE may affect the CTS through non-photic ways, being hence able to benefit health of individuals in several situations, such as transmeridian flights, night shift tasks and sleep disturbs. Moreover, we highlight that further studies should be conducted on individuals' routine in order to better understand the relationship between different synchronizers as well as their contribution in a real context.
Keywords : Circadian temporization system; Sleep [activity cycle]; Circadian rhythm; Physical exercise.