Sleep supplements (melatonin, glycine, magnesium) C
Sleep is critical, but the evidence of benefit of supplements for performance is weak
Citable fact
«Sleep supplements (melatonin, glycine, magnesium)» — evidence level C. Dosage: Melatonin 0.5-5 mg (less for shifting the rhythm, several hours before sleep); glycine 3 g before sleep; magnesium 200-400 mg elemental. There are no single ergogenic doses. Source: PMID 35708888, permanent link to the source in the list below.
How it works
Sleep provides recovery and growth hormone secretion; its deficit worsens performance and increases the risk of injury. Melatonin shifts the circadian rhythm, while glycine and magnesium affect the central nervous system.
Dosage and intake
Melatonin 0.5-5 mg (less for shifting the rhythm, several hours before sleep); glycine 3 g before sleep; magnesium 200-400 mg elemental. There are no single ergogenic doses.
30-60 minutes before sleep; melatonin for jet lag - 30 minutes before the target sleep time in the new time zone.
Forms
Melatonin (immediate and sustained release), glycine, magnesium and valerian have been studied. There are no data on most "sleep" complexes, and their composition is often unclear.
What is confirmed
- Sleep deficit reliably worsens endurance, strength and movement accuracy - this is confirmed by meta-analysis
- Melatonin shortens the time to fall asleep and eases circadian rhythm shifts on flights
- Magnesium and glycine slightly improved subjective sleep quality in small studies
- A direct effect of these supplements on sports performance has not been shown
Adverse effects and limitations
- Melatonin causes drowsiness, headache and vivid dreams; taken at the wrong time it shifts the rhythm the wrong way
- The long-term safety of melatonin in healthy adults has not been confirmed
- Supplements do not compensate for chronic sleep deprivation and poor sleep hygiene
- Magnesium in large doses causes diarrhea
Interactions
- Sedatives and hypnotics: increased drowsiness
- Warfarin, fluvoxamine and other drugs metabolized through cytochrome P450: melatonin changes their concentration
- Immunosuppressants: caution when taking melatonin
Who must not use it
- Under 18 years: Melatonin for children - only as prescribed by a physician; in sport it is not recommended without indications.
- Pregnancy and lactation: Melatonin is not recommended during pregnancy; magnesium - as indicated.
- autoimmune diseases
- epilepsy
- liver and kidney disease
- taking sedative drugs
Sources
- Effects of Acute Sleep Loss on Physical Performance: A Systematic and Meta-Analytical Review · Craven J, McCartney D, Desbrow B · Sports medicine (Auckland, N.Z.), 2022 · PMID 35708888
- Sleep and athletic performance: the effects of sleep loss on exercise performance, and physiological and cognitive responses to exercise · Fullagar HH, Skorski S, Duffield R · Sports medicine (Auckland, N.Z.), 2015 · PMID 25315456
- Prevention, diagnosis, and treatment of the overtraining syndrome: joint consensus statement of the European College of Sport Science and the American College of Sports Medicine · Meeusen R, Duclos M, Foster C · Medicine and science in sports and exercise, 2013 · PMID 23247672
- 2023 International Olympic Committee's (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs) · Mountjoy M, Ackerman KE, Bailey DM · British journal of sports medicine, 2023 · PMID 37752011
See also
Comparisons
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