EFFECTS OF DIURNAL AND NOCTURNAL STRENUOUS EXERCISE ON SERUM MELATONIN LEVELS

Mehmet Kilic,Rasim Mogulkoc,Suleyman Patlar,Bilal Demirhan,Abdulkerim Kasim Baltaci

doi:10.1590/1517-869220162206134684

Mehmet Kilic, Rasim Mogulkoc + Show 3 more

Open Access

https://doi.org/10.1590/1517-869220162206134684

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Abstract

ABSTRACT Introduction: There are reports of a possible relationship between melatonin, a hormone secreted by the pineal gland, and exercise. Objective: The present study aims to investigate how diurnal and nocturnal strenuous exercise affects melatonin levels. Methods: The study enrolled 10 healthy sedentary males who did not actively exercise. The subjects had a mean age of 22.20±0.24 years, a mean height of 174.60±2.33 cm, and a mean weight of 69.70±2.42 kg. Two blood samples were collected from the subjects, one at rest, at 10:00 am, and the other immediately after strenuous exercise. Likewise, blood samples were taken from the same group of subjects after 48 hours: at 24:00 hours at rest and immediately after strenuous exercise. Samples were analyzed using the ELISA method to determine the serum melatonin levels (pg/ml). Results: By comparing the values at rest and after exercise, it was found that serum melatonin values remained unchanged with exercise. Serum melatonin values at rest or post-exercise measured at night were higher when compared with those measured during the day (p<0.05). Conclusions: Higher levels of melatonin found in the study appear to result from the increased release of melatonin at night, and not from exercise. The results of this study indicate that strenuous exercise carried out day or night, did not significantly influence serum melatonin levels.

Highlights

There are reports of a possible relationship between melatonin, a hormone secreted by the pineal gland, and exercise
The results of this study indicate that strenuous exercise carried out day or night, did not significantly influence serum melatonin levels
In a study where the effects of melatonin on carbohydrate and lipid metabolism were examined, the experimental animals were run to exhaustion at 24 m/min and a 12% slope and it was observed that exercise caused significant hypoglycemia, elevated plasma lactate and beta-hydroxybutirate levels, and led to a significant decrease in glycogen in the muscles and liver

Summary

Introduction

There are reports of a possible relationship between melatonin, a hormone secreted by the pineal gland, and exercise. The same study showed that muscle and liver glycogen content was significantly higher, while plasma and liver lactate, as well as plasma beta-hydroxybutirate levels were significantly lower in melatonin-treated exercised rats. These data were interpreted as an indication of melatonin’s preservation of glycogen stores through the changes in carbohydrate and lipid utilization in exercised rats[3]. It was noted that elevated plasma lactate levels following pinealectomy could cause muscle tiredness, producing a negative effect on performance, whereas melatonin administration could delay tiredness and improve physical performance[4] Another remarkable example of the relation between melatonin and exercise is the report that melatonin administration restored the reduced liver glycogen levels in rats subjected to an acute swimming exercise[5]. The fact that melatonin preserves muscle and liver glycogen in exercised rats suggests that melatonin may prolong exercise duration in humans[6]

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