Last updated: October 2026
Active people may need a little more magnesium, as hard training increases losses in sweat and urine by an estimated 10 to 20%. Magnesium contributes to normal muscle function, electrolyte balance and energy-yielding metabolism. Supplements mainly help athletes who are low in it; reviews find little performance benefit if your intake is already adequate. Glycinate is a gentle, well-absorbed form.
Below: why athletes need magnesium, what the research shows for performance and recovery, why glycinate, dose and timing, food sources and safety.
Why active people need magnesium
Magnesium is involved in energy production, muscle contraction and relaxation, and fluid balance. A 2006 review estimated that strenuous exercise increases magnesium needs by 10 to 20% because of extra losses. Athletes who restrict food to make weight, or eat few whole grains, nuts, seeds and greens, are most likely to fall short. See signs of magnesium deficiency.
Does magnesium improve performance or recovery?
| Study | What it found |
|---|---|
| Review, 2017 | Magnesium supplements may improve performance in people who are low in magnesium; benefits in people with adequate intake are unclear |
| Soreness trial, 2022 (22 young adults) | 350mg a day for 10 days reduced muscle soreness and improved perceived recovery after weight training |
| Cramps, Cochrane 2020 | No trials yet in exercise cramps; unlikely to help night cramps in older adults |
So magnesium is about filling a gap rather than a performance boost. See magnesium for muscle pain and magnesium for cramps.
Why glycinate?
| Form | For active people |
|---|---|
| Glycinate (bisglycinate) | Well absorbed and gentle on the stomach, so less likely to cause loose stools around training |
| Citrate | Well absorbed; can loosen stools, best away from sessions |
| Oxide | Poorly absorbed; most likely to upset the stomach |
Our Magnesium Glycinate Sleep Complex combines bisglycinate and citrate with glycine, L-theanine and botanicals, giving 148mg of magnesium per serving as an evening drink, to fit the recovery part of your day. See types of magnesium and magnesium glycinate.
Dose and timing for training
- Daily needs: 300mg (men) or 270mg (women), mostly from food, says the NHS; heavy training may raise needs a little.
- Supplements: 400mg a day or less is unlikely to cause harm.
- Timing: evening suits most people, away from hard sessions to avoid stomach upset. See best time to take magnesium.
- Sleep: most recovery happens overnight. See magnesium for sleep and late-night sport and sleep.
Food first
Good training-friendly sources include oats, wholemeal bread, brown rice, beans and lentils, nuts and seeds (pumpkin seeds especially), spinach, bananas and dark chocolate. A diet built around these usually covers your needs; a supplement is a backup.
Safety and anti-doping
- Loose stools are the main side effect at higher doses.
- Kidney disease: don’t take magnesium supplements without medical advice.
- Medicines: separate from some antibiotics and osteoporosis medicines.
- Tested athletes: magnesium isn’t banned, but any supplement carries a small contamination risk. Check batch-tested products and UK Anti-Doping guidance. If you also use CBD, see CBD for athletes and CBD and HRV for runners.
- Pregnancy and breastfeeding: we don’t recommend our products during pregnancy or breastfeeding.
FAQs
Do athletes need more magnesium?
Probably a little. Hard training is estimated to raise needs by 10 to 20% through sweat and urine losses.
Does magnesium improve athletic performance?
Mainly in people who are low in it. Benefits for athletes with adequate intake are unclear.
Is magnesium glycinate good for athletes?
It’s well absorbed and gentle on the stomach, which suits people training hard. No form is proven best for performance.
Should I take magnesium before or after training?
Timing matters less than consistency. Many take it in the evening, away from sessions, to avoid stomach upset.
Does magnesium help muscle recovery?
One small trial found 350mg a day reduced soreness after weight training. Magnesium contributes to normal muscle function.
Sources
- Nielsen FH, Lukaski HC. Update on the relationship between magnesium and exercise. Magnes Res, 2006.
- Zhang Y et al. Can magnesium enhance exercise performance? Nutrients, 2017.
- Reno AM et al. Effects of magnesium supplementation on muscle soreness and performance. J Strength Cond Res, 2022.
- NHS. Vitamins and minerals: magnesium.
