Magnesium for Muscles: Does It Really Help?

meta-analysis PMID: 29637897

Quick Summary: Research suggests magnesium supplements might help improve muscle function, but it depends on who you are. This study found no benefit for athletes or active people, but it could help the elderly or people with low magnesium levels.

What The Research Found

This study looked at lots of other studies to see if magnesium supplements help with muscle strength and performance. The main finding? If you're already healthy and active, magnesium probably won't give you a boost. However, the research hinted that magnesium could help older adults or people who drink a lot of alcohol, who might have low magnesium levels.

Study Details

Who was studied: The researchers looked at data from 14 different studies. These studies included:

Athletes and active people
Healthy but not very active people
Elderly people and people with alcohol use disorder

How long: The studies varied in length, but the summary doesn't specify the exact duration.

What they took: The study doesn't specify the exact magnesium dosage or type of magnesium used.

What This Means For You

Active and Healthy? If you're already getting enough magnesium through your diet (think leafy greens, nuts, and seeds) and you're physically active, magnesium supplements probably won't make you stronger or improve your performance.

Older Adults or Alcoholics? If you're older or drink a lot of alcohol, you might be low in magnesium. In this case, magnesium supplements could help with muscle function. Talk to your doctor to see if a magnesium test is right for you.

Focus on Food First: No matter who you are, focus on getting magnesium from your diet.

Study Limitations

Not Everyone the Same: The studies used different groups of people, different amounts of magnesium, and measured different things.

Missing Info: The studies didn't always measure how much magnesium people had before they started taking supplements.

Small Groups: The group of elderly and alcoholic participants was smaller, so the results are less certain.

Short Studies: Many studies were short, so we don't know the long-term effects.

Key Findings

This 2017 meta-analysis found no significant overall benefit of magnesium (Mg) supplementation on muscle fitness metrics (e.g., peak torque, strength, power) in athletes/physically active individuals or untrained healthy adults. However, subgroup analysis revealed potential benefits in populations with likely Mg deficiency: elderly individuals and alcoholics. The authors concluded that Mg supplementation may only enhance muscle fitness in those with low baseline Mg status.

Study Design

A systematic review and meta-analysis of randomized clinical trials (RCTs) was conducted, pooling data from 14 studies (total n = 542 participants). Populations included:
1. Athletes/physically active (n = 215, mean age 24.9 years)
2. Untrained healthy individuals (n = 95, mean age 40.2 years)
3. Elderly/alcoholics (n = 232, mean age 62.7 years)
Studies were sourced from Medline and other databases up to July 2017. Outcomes included leg strength, peak torque, muscle power, and functional tests (e.g., walking speed, chair stands). A fixed-effects model calculated weighted mean differences (WMDs) with 95% confidence intervals (CIs).

Dosage & Administration

The study summary did not specify exact Mg doses, forms (e.g., magnesium citrate), or administration protocols (e.g., duration of supplementation). This lack of detail limits interpretation of dose-response relationships.

Results & Efficacy

Pooled analysis of all populations showed no statistically significant improvements in:
- Isokinetic peak torque extension: WMD = 0.87 (95% CI: -1.43, 3.18)
- Muscle strength: WMD = 0.87 (95% CI: -0.12, 1.86)
- Muscle power: WMD = 3.28 (95% CI: -14.94, 21.50)
Subgroup analysis suggested trends toward benefit in elderly/alcoholic populations, though these were not quantified in the summary. No improvements were observed in athletes or active individuals, who likely had adequate Mg levels at baseline.

Limitations

Heterogeneity: Populations, Mg dosages, and outcome measures varied across studies.
Publication bias: Smaller trials with null results may be underrepresented.
Baseline Mg status unreported: Most studies did not measure participants’ initial Mg levels, making it unclear if effects were tied to correcting deficiencies.
Short duration: Many trials lasted ≤3 months, limiting insight into long-term efficacy.
Limited elderly/alcoholic data: Only 232 participants in this subgroup, reducing statistical power.

Clinical Relevance

For athletes or active individuals with normal Mg intake, supplementation likely offers no measurable muscle fitness benefits. However, older adults or those with Mg deficiency (e.g., alcoholics) may experience improvements in strength or functional mobility. Users should prioritize dietary Mg (e.g., leafy greens, nuts) and consider serum Mg testing before supplementation. Future research should target Mg-deficient populations and standardize dosing protocols.

Note: This analysis reflects only the provided study summary; full details (e.g., specific dosages, trial durations) may alter conclusions.