7 Common Mistakes You’re Making That Cause Muscle Cramps When Running

From a lack of sleep to not warming up ahead of time, here's what causes cramps when running, according to the experts.

What causes cramps when running, according to experts

1. Lack of sleep

What's your sleeping schedule like? If you're not getting enough shut-eye every night, you could be setting yourself up for cramps during your runs. "When you don’t sleep, you don’t recover, which leads to injuries and cramps," says avid marathon runner Quan Bailey, certified personal trainer and Isopure athlete. "Your muscles need time to rebuild in order for you to run effectively."

The next time you wake up in the middle of the night, use these tips to fall back asleep:

2. Improper hydration

Staying hydrated affects everything from your skin and energy levels to—you guessed it—cramping during a workout. "Being dehydrated is never good—especially going into a run," says Casey Green, a Charge Running coach. "Not getting enough water into your system in the hours leading up to your training can cause cramps within a few miles of getting started."

3. Skipping your warm-ups and stretches

If you're not taking the time to warm up or stretch before your runs, you might want to change that. "A lot of us start our races or runs too fast without giving our bodies a chance to warm up," says Bailey. "I often see this in marathons; people get excited to run when the gun goes off, and the excitement leads them to run too fast. That causes them to run out of energy or nutrients during the race, which is usually followed up with a cramp. Make sure you stretch and start the run a little slower."

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Start with this five-minute running warm-up to prevent cramps:

4. Lack of electrolytes

While dehydration can cause muscle cramps, so can electrolyte depletion. "Low levels of electrolytes—such as potassium, calcium, magnesium, and sodium—can contribute to leg cramps, most often felt by your quadricep and calf muscles tightening up during a run," says Raj Hathiramani, a certified running coach for Aaptiv. "Fluids with electrolytes keep your muscle cells hydrated and less prone to involuntary spasms."

5. Eating too close to your run

Green says to avoid sneaking in a last-minute snack or meal before your run unless you're sure your body can handle it. "Trying to cram in proper running fuel 30 to 60 minutes before a run can absolutely lead to cramping," he says. "Keep it light, simple, and low-sugar if you need to eat right before your run, like a granola bar, piece of bread, or piece of fruit. All of these things will give you just enough fuel and minimize the possibility of a mid-run cramp."

6. Medication side effects

It's always a good idea to talk to your doctor about any side effects of meditations you're on. "One of the best predictors of cramping is whether you’ve cramped in the past, so be aware of any side effects of existing or new medications you're taking—especially ones that may limit blood supply necessary for higher-intensity exercise like running," says Hathiramani. "Respect your underlying conditions and side effects of any medications, which may put you at a higher risk of muscle cramps."

7. Weak muscles

Muscle cramping during running can also be due to a lack of muscle. "Sometimes a cramp anywhere in a runner's body may be a sign that the muscles are fatiguing and can no longer voluntarily contract properly," says Green. "This can come from avoiding strength and flexibility workouts. It’s always the little things that make the biggest difference over the course of a run."

Improve your strength with this core workout for runners:

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