Melatonin may indirectly improve sporting performance: Review
Writing in the journal Nutrients, the team of Spanish researchers attributed the ergogenic effects of supplementation to melatonin's anti-inflammatory and antioxiodant properties.
“Melatonin supplementation could act indirectly to improve performance by preventing tissue damage and helping to reduce inflammation caused by RONS [reactive oxygen and nitrogen species], restoring circulating biomarkers that go out of the normal range in highly trained athletes when performing very demanding exercises,” they wrote.
Melatonin and exercise recovery
The neurohormone melatonin is naturally synthesized and secreted into the central nervous system to modulate an array of physiological functions, most notably the regulation of the sleep/wake cycle and circadian rhythms. Melatonin also exhibits anti-aging, neuroprotective and cardioprotective functions through its antioxidant, anti-inflammatory and immunomodulatory activities.
Given these properties, an increasing interest in melatonin for sports recovery responds to the understanding that increased physical and biochemical demands of highly demanding physical activity can increase nutrient consumption and the accumulation of harmful molecules such as free radicals.
Yet, the underlying mechanisms behind melatonin’s potential recovery benefits is not fully understood, a gap the present review sought to fill by summarizing the available evidence surrounding its effect on circulating biomarkers.
Review details
The systematic review searched the PubMed, Scopus and Web of Science databases based on a set of key words and inclusion criteria to generate a total of 21 articles for inclusion. The studies investigated melatonin dosages ranging from 5 mg to 100 mg, administered before and after exercise.
Supplementation was found to improve antioxidant status and inflammatory response, while also reversing liver, muscle and tissue damage.
In addition, moderate effects were noted for glycemia, totally cholesterol, triglycerides and creatinine modulation. Data also suggested that consuming melatonin may benefit haematological biomarkers, hormonal responses and sports performance.
While the findings did not show a direct positive effect of melatonin supplementation on exercise performance, the researchers indicated that “an indirect effect of melatonin supplementation in sports performance could be evaluated through improvements in health biomarkers".
This included improved antioxidant status in the melatonin group, an effect which the researchers explained resulted from improved activities of superoxide dismutases (SOD), catalase (CAT) and glutathione peroxidase (GPx). Glutathione (GSH) levels were also significantly increased.
“Melatonin improves inflammatory status in athletes through a significant reduction in the secretion of IL-6 and TNF-α, as well as in acute phase reactants such as CRP and a significant increase in anti-inflammatory mediators, including sTNF-α-RII and IL1-ra," they wrote. “Melatonin modulates inflammation by inhibiting the activation of the NF-κB, JAK/STAT, and MAPK signalling pathways."
Source: Nutrients
doi: 10.3390/nu16071011
“Impact of Melatonin Supplementation on Sports Performance and Circulating Biomarkers in Highly Trained Athletes: A Systematic Review of Randomized Controlled Trials”
Authors: Ana M. Celorrio San Miguel et al.
