For access to all of our training, gear, and race coverage, plus exclusive training plans, FinisherPix photos, event discounts, and GPS apps, sign up for Outside+.
Muscle cramps are annoying and sometimes debilitating during training and racing. There are several factors that can attribute to muscle pain including electrolyte imbalance, dehydration, and load placed on a muscle group.
Written by: Jordan Metzl
Tiffany is a 33-year-old triathlete who visits me for quadriceps cramping. “Dr. Metzl, every time I start running for more than an hour my muscles cramp up on me. It’s worst in the spring and summer. What can I do?”
“Tiffany, we can fix this,” I tell her.
Muscle cramping is an annoying problem for sure. It means the muscle is objecting to something; our job is to figure out what that is and fix it.
The two most common types of muscle cramps are functional and nutritional.
Functional Muscle Cramping
Functional muscle cramping means that the load placed on a muscle group is greater than the muscle’s ability to withstand the force. I’m a huge fan of strength training for runners and triathletes. Weak muscles are unhappy, so they cramp when they can’t withstand the load being placed on them. How does an athlete know if they have functional muscle cramping? Clues can include cramping that happens during periods of intense exertion, often with speed and hill training. I also see functional muscle cramping at the start of the race season in athletes who’ve taken the winter off and not done proper base or strength training. The key to fixing functional muscle cramping is often building strength. Exercises such as plyometrics are excellent strength builders and should be done all year long and especially during the off-season.
Nutritional Muscle Cramping
Nutritional cramping is the result of electrolyte imbalance, dehydration or both. When muscle is deprived of enough water (basic dehydration), it tends to cramp. Hot, humid days and quick temperature increases that don’t allow time for heat acclimatization are frequent scenarios for dehydration-based cramping. With a greater understanding of muscle physiology, however, much greater attention in recent years has been given to cramping due to electrolyte imbalance, particularly with regard to sodium. For years, athletes were told, “If you’re cramping, eat bananas.” Although well-intentioned advice, bananas are rich in potassium which is an end-stage type of electrolyte depletion that is quite uncommon. Sodium-related cramping is much more common.
When athletes loose salt, muscles start to cramp. These can include hamstrings, quads and even the small muscles in the feet or hands. The way to tell if sodium-related muscle cramping is happening is to check to see if you’re loosing more salt than your friends. Is your skin caked in salt after a hard workout? If so, are you cramping? Fixing sodium-related cramping is easy. Increase salt intake before and during workouts. This can include foods such as pretzels, salted Goldfish crackers or some of the specific products designed to balance electrolytes. Salt loading in the eight hours before a strenuous workout can help load sodium stores.
As for Tifanny, we determined that her muscle cramping was a combination of both functional and nutritional. She was delinquent on her strength all winter so I started her on some plyometric jump squats to build strength. She is also a salty sweater, so I increased her sodium intake before and during her workouts. Tiffany is now cramp-free and ready to rock her spring and summer training.
Jordan D. Metzl, M.D., Drjordanmetzl.com, is a nationally recognized sports medicine specialist at Hospital for Special Surgery in New York City. In addition to his medical practice, Metzl is a 28-time marathon runner and eight-time Ironman finisher.