Night Leg Cramps After 50: Do Magnesium or Stretching Help?

A calf cramp at 3 a.m. can leave you hopping on a cold floor. Magnesium is the remedy most people reach for. Here is what trials found for it and for stretching.

Magnesium

A 2020 Cochrane review pooled 11 trials with 735 people.¹ For ordinary night cramps in older adults, average age 62 to 69:

• Magnesium made almost no difference to how often cramps came: about 0.18 fewer cramps a week than placebo, a difference too small to matter.¹
• It caused more stomach upset, mostly diarrhea, in up to 37% of people taking it.¹
• The authors concluded it’s unlikely to prevent cramps in older adults.¹

For cramps in pregnancy, the evidence was conflicting.¹ For cramps from conditions like liver disease, there was almost no evidence.¹

Stretching: two trials, two answers

Trial	Who	Result
2012 trial	80 adults over 55, calf and hamstring stretches nightly before bed for 6 weeks2	Cramps fell by about 1.2 per night more than in the no-stretch group, and were less severe2
England, 2005	191 people already on quinine for cramps, advised to do calf stretches3	No difference in cramp frequency or severity at 12 weeks3

The 2012 trial taught specific stretches just before sleep; the 2005 trial gave advice to people already on a medicine.²³ Stretching is free and low-risk, so it’s a reasonable first try.

The 2005 trial also found that many people on long-term quinine could stop it without major problems.³ Quinine carries serious risks; see quinine for night cramps.

Cramp, or restless legs?

A cramp is a hard, painful muscle knot that eases when you stretch it. Restless legs is an urge to move with uncomfortable feelings, worse at rest and in the evening, eased by walking. They’re treated differently. See why your legs feel restless at night.

Try tonight

1. Stretch calves and hamstrings for a few minutes right before bed.
2. When a cramp hits, flex your foot up toward your shin or stand and lean into the stretch.
3. Log for two weeks: cramps per night and how bad. Bring the log if they keep waking you.

Try: “I get calf cramps three or four nights a week and magnesium hasn’t helped. Could any of my medicines be causing them, and is there anything else to try?”

Did I Do That in My Sleep? covers leg trouble at night in Chapter 8, “The Things You Apparently Said,” in a section called “The Legs That Won’t Settle.” It asks you to describe what you feel, what rest does and what moving does, which is how a clinician tells a cramp from restless legs. See the book.