Comparatively examining the effects of exercise time on body metabolic, cardiovascular, endocrine and oxidant antioxidant systems between sedentary and trained subjects

Physical activity and regular exercise training are important for improving human health. However, exercise can be harmful via disturbing balance between oxidant and antioxidant systems. Despite the agreement among the investigators concerning the optimal exercise intensity and duration, there is no satisfactory knowledge on effective exercise time on improving cardiopulmonary and metabolic systems. In the present study, initially, we examined to understand the optimal exercise time on energy-regulatory system via affecting irisin and nesfatin-1 which has been shown as exercise related hormones. Then, we interested to investigate possible relationship between oxidant and antioxidant systems of the heart and skeletal muscle in response to the exercise performed on different times of the day. Fourteen sedentary and fourteen trained subjects participated 3 football games on morning (8:00-10:00 h), afternoon (14:00-16:00 h) and late night (20:00-22:00) on different days. Venous blood samples (5 ml) were drawn before and immediately after the games. Irisin, nesfatin-1, NADPH oxidase, TOS, TAS and glutathione levels were measured using ELISA method. HPLC used to analyse ADMA and MDA and auto-analyser used to measure CK and CK-MB. While nesfatin-1 increased only in night time exercise, irisin increased significantly in all exercise in both groups. NADPH oxidase, TOS and MDA levels, reflecting oxidative stress status of body, increased significantly in both group during 3 games but in higher degree in sedentary group and especially night exercise. ADMA, CK and CK-MB, reflecting oxidative stress status of cardiovascular systems, increased in both group for all exercise but they increased markedly in sedentary group and especially in night exercise. TAS, reflecting body antioxidant systems, decreased in both group in all games. Glutathione which is another strong antioxidant decreased in morning and afternoon games in both groups but it increased significantly in night time exercise in both groups. While irisin is an exercise related hormone, nesfatin-1 does not seem to be related with exercise and only increased in night time. However, exercise time, especially night, has serious influence on the balance between oxidant-antioxidant systems. The person who has weakness in metabolic and cardiovascular system, should be careful to avoid night time exercise even for leisure activity or fun. Keywords: Nocturnal exercise, Oxidative stress, Exercise time, Metabolism, Cardiovascular system