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Insomnia (as defined by the Diagnostic and Statistical Manual of Mental Disorders-IV) is prevalent in about one-third of the general population. In terms of optimal performance and recovery, insomnia severely restricts what the body can handle; NOTHING will be more beneficial for performance and recovery than sufficient, quality sleep. Melatonin is a popular supplement commonly used to help get to sleep. It’s also an endogenous hormone in the body that regulates sleeping patterns (more melatonin is synthesized in darkness). People have used melatonin supplementation for several reasons, ranging from sleep regulation to the treatment of solid tumors. However, this article will focus on the effects pertaining to recovery and exercise performance, starting with better sleep.
Before getting into any of the extra benefits supplemental melatonin may offer, it’s important to get the easy stuff right—sleep hygiene. Sleep hygiene consists of the small changes you make to your bedtime routine that can significantly increase your quality and length of sleep. Some great changes to make (in order of importance) are:
- During the day, bask in the light. When it’s close to bedtime, limit exposure. This will help your body know when it’s time to be awake and alert, and when it’s time to relax and sleep.
- Dim or turn off your lights when it’s getting closer to when you want to sleep (I turn them all off 15 minutes before I want to be in bed). Invest in some blackout curtains (even if you use a sleep mask, your skin reacts to the light as well). Avoid using your phone, tablet, computer, or any other artificial light sources.
- Avoid stimulants.
- This is an obvious one; caffeine, pre-workout, and nicotine are all going to make it more difficult to sleep. However, don’t use alcohol to help with sleep either. Alcohol will make you fall asleep faster but the quality of sleep will be much poorer.
- Create a relaxing environment.
- A cool temperature (60-70oF/16-21oC), a comfortable bed and supportive pillow, and consistent background noise (to drown out other noises that could disrupt sleep) are great ways to enhance the sleeping environment. Included in this is the information from the first bullet about limiting light exposure.
- Establish a bedtime routine.
- Habits help the body know what to do. If every night you read, stretch, meditate, etc. before bed, your body will recognize the routine and prepare for sleep.
- Limit naps.
- A short nap (<30 minutes) can help with performance, but any longer than that and normal nighttime sleep can be disrupted.
Even if nothing additional is used, these simple sleep hygiene tips can greatly improve your length and quality of sleep. With these in mind, we can now delve into the additional benefits melatonin has to offer when taken as a supplement. One experiment that I found was particularly interesting and applicable to people that lift; the study looked at the effects of supplementing 100 mg of melatonin (versus placebo) 30 minutes before bed in resistance-trained athletes. Blood samples were taken before the intervention and following the four week training. The athletes in the melatonin supplementation group reduced creatine kinase (CK), lactate dehydrogenase (LDH), creatinine, and total cholesterol levels. The first three parameters (CK, LDH, creatinine) are used as markers of muscular damage or oxidative stress on the muscle. The data show a beneficial effect of melatonin supplementation (at least in resistance-trained athletes) due to the amelioration of oxidative stress induced by exercise and the muscle protection against exercise-induced oxidative damage. Since the study only lasted four weeks, it’s difficult to say if the benefits seen in the melatonin group would lead to enhanced performance over a longer period of time, but it is still useful to have a study observing melatonin supplementation in resistance-trained athletes.
Melatonin has long been known as an antioxidant and neuroprotectant. With exercise, the effects of melatonin are enhanced beyond what only exercise or melatonin alone can provide. This is true even in situations of nerve injury and Alzheimer’s (as studied in rat models). When the melatonin (at a dose of 10 mg/kg) was supplemented in addition to exercise, nerve injuries maintained more functional capability due to more motor neurons being protected from secondary damage (the secondary damage being likely due to an inducible Nitric Oxide synthase, as NO can magnify neuronal damage). When added to exercise in the Alzheimer’s case, the melatonin supplementation protected against cognitive impairment, brain oxidative stress, and mitochondrial damage. The combination was also able to prevent a decrease in the number of mitochondria—important for neuronal energy (“mitochondria are the powerhouse of the cell” as anyone that had a 6th grade biology class knows). Combining all of this information together, it provides further support for melatonin supplementation.
Higher uric acid levels have been shown to induce oxidative stress, triglyceride accumulation, and mitochondrial dysfunction; high levels are present in over one-fifth of the US population. The prevalence of high uric acid has been increasing along with the prevalence of obesity (higher insulin in obese individuals prevents the kidneys from being able to properly eliminate uric acid). It’s even an independent predictor of type 2 diabetes. By now I’m sure you’re wondering why I’m talking about uric acid; how does this relate to melatonin at all? Well, in a very recent study, the effects of melatonin were observed to offset the detrimental effects of high uric acid levels that can cause damage to muscle. Melatonin assisted in preventing the oxidative stress, triglyceride accumulation, and mitochondrial dysfunction resulting from the high uric acid levels. While most fit individuals would be unlikely to have high uric acid levels (or type 2 diabetes), some do, and supplemental melatonin offers them some more protection.
Again looking at type 2 diabetes (this time in rat models), melatonin supplementation along with exercise seems to be beneficial for insulin sensitivity, blood pressure, and fatigue/exercise performance. Since these benefits were seen in type 2 diabetes, it’s difficult to be sure if they would apply to individuals that are healthy and exercise regularly. However, the potential of improved insulin sensitivity and exercise performance through up-regulated glucose transporters and mitochondrial biogenesis is definitely interesting and another factor to consider when using melatonin supplementation for recovery and exercise performance.
Finally, to wrap up this article I want to go into some of the worries many people have concerning melatonin. Melatonin is a very safe supplement overall and has very few problems associated with it; most of the worries people have are due to connecting melatonin to sleeping pills, even though they have different mechanisms of action (melatonin appears to increase the binding of GABA to its receptors by affecting membrane characteristics, not by increasing the number of receptors or enhancing the effects of GABA like common sleeping pills do). Melatonin does have some side effects such as sedation/fatigue as well as some mild decreases in core body temperature, but nothing like some of the worries people have that are stated below:
- Melatonin taken at night does not impair physical performance the next day; viewed as a “hangover” effect similar to what someone may experience if they took a prescription sleeping pill such as Ambien (zolpidem). Athletes that were given 5 mg of melatonin the night before a test of physical performance did not perform worse or feel any more sluggish than a control group.
- Another worry is again connected to some effects of taking prescription sleeping pills/benzodiazepines—withdrawal and/or dependence. There is not any quality evidence that supports melatonin causing physical dependence or withdrawal symptoms upon discontinuing supplementation. It’s possible that people with insomnia that discontinue melatonin may see their insomnia return, but that’s the closest anyone would get to dependence or withdrawal.
- One last worry I’ve heard is the concern of supplemental melatonin on natural production in the body. Even with melatonin doses over 30 mg, endogenous levels of melatonin produced by the pineal gland remained relatively constant and continued to remain constant after discontinuing supplementation (further support for a lack of dependence/withdrawal).
I hope this information was useful for helping to make a decision on melatonin supplementation. Melatonin has been used and studied for much more than just sleep and exercise performance, so I thought an article devoted purely to those benefits would be useful. Personally, I supplement with melatonin and would recommend others to use it. I recommend starting at a dose of 0.5 mg and eventually going up to 3-5 mg.
- Melatonin is an effective supplement for falling asleep, especially when combined with good sleep hygiene.
- Sleep hygiene will help with sleep and recovery from exercise, with or without melatonin.
- Melatonin supplementation can lessen oxidative stress from exercise as well as offer protection from oxidative damage to muscle.
- Melatonin may help protect against the effects of high uric acid.
- Particularly when combined with exercise, melatonin has a neuroprotective effect.
- Melatonin may help with insulin resistance, high blood pressure, and fatigue.
- Melatonin does not seem to have any lasting “hangover” effects that would impair physical performance.
- There does not seem to be any physical dependence from melatonin or withdrawal if discontinued.
- Endogenous melatonin levels remain relatively constant even with supplementation.
- Recommendation: start with a 0.5 mg dose for supplementation and eventually increase to 3-5 mg, especially if you also have trouble falling asleep.
Leonardo-Mendonça RC, Ocaña-Wilhelmi J, de Haro T, et al. The benefit of a supplement with the antioxidant melatonin on redox status and muscle damage in resistance-trained athletes. Appl Physiol Nutr Metab. 2017 Jul;42(7):700-707.
Park K, Lee Y, Park S, et al. Synergistic effect of melatonin on exercise-induced neuronal reconstruction and functional recovery in a spinal cord injury animal model. J Pineal Res. 2010 Apr;48(3):270-81.
García-Mesa Y, Giménez-Llort L, López LC, et al. Melatonin plus physical exercise are highly neuroprotective in the 3xTg-AD mouse. Neurobiol Aging. 2012 Jun;33(6):1124.e13-29.
Maarman GJ, Andrew BM, Blackhurst DM, Ojuka EO. Melatonin protects against uric acid-induced mitochondrial dysfunction, oxidative stress, and triglyceride accumulation in C2C12 myotubes. J Appl Physiol (1985). 2017 Apr 1;122(4):1003-1010.
Rahman MM, Kwon HS, Kim MJ, Go HK, Oak MH, Kim DH. Melatonin supplementation plus exercise behavior ameliorate insulin resistance, hypertension and fatigue in a rat model of type 2 diabetes mellitus. Biomed Pharmacother. 2017 Aug;92:606-614.
Atkinson G, Buckley P, Edwards B, Reilly T, Waterhouse J. Are there hangover-effects on physical performance when melatonin is ingested by athletes before nocturnal sleep? Int J Sports Med. 2001 Apr;22(3):232-4.