Muscle cramps are a runner’s nightmare. One moment you’re flying, the next you’re hobbled, in agony, your race goals down the drain. For years we pointed fingers at dehydration or electrolyte loss as the culprits. But neither cause holds up to close examination. Studies on ultra-distance runners and triathletes indicate that neither hydration nor electrolyte status is directly associated with cramping—even if you seem to cramp more on hot days. Conventional wisdom fails again.
The cause of exercise-induced muscle cramps is multifactorial and there are still questions to answer, but an emerging picture is this: Cramps are probably the result of altered neuromuscular control. Altered neuromuscular control comes from fatigue in working muscles. One source of fatigue is faster-than-normal pacing (more evidence here, and here.) One study says, “Evidence suggests that runners are placing greater demands on their muscles during the race relative to their current state of training.”
Muscle damage, possibly from incomplete pre-race tapering (more evidence here) and prior injury (more evidence here) to the cramping muscles also contribute to fatigue and cramps. Other contributing factors include chronic illness, family history, and certain medications.
Altered Neuromuscular Control
Running happens through groups of muscles working in coordination. Uphill running demands work from the glutes, quads, hamstrings, adductors, and calves. Downhill running requires shock absorption from the quadriceps, hamstrings, and adductors as well as the connective tissue of the knees, hips, back, and feet. Hip abductors, feet, and lower legs work constantly in all phases of running, both in propulsion and shock absorption. If one muscle can’t contribute adequately then it means another muscle or muscles must work harder, thus risking cramps.
If you’ve ever tried executing a complex task requiring precise movement when you’re exhausted, you understand altered neuromuscular control. You’re stiff and clumsy. Altered neuromuscular control happens at both a conscious and unconscious level.
Successful running requires variable amounts of precisely regulated tension; think of a light controlled by a dimmer switch. Running rarely requires either full contraction or full relaxation of the working muscles. The ability to modulate muscular contractions diminishes with fatigue. A cramp happens as a result of the neural dimmer switch getting stuck in the “on” position as a consequence of fatigue.
Specific training is the first line of defence against cramps. Training specifically means regularly running on terrain similar to your race. Preparing for the Boston Marathon is a good example. Boston’s infamous Newton Hills sit between miles 17 and 21. Here, runners must climb and descend multiple times while fatigued—not only by the previous miles, but also by significant downhills during those miles. Thus, training should include hill runs at the end of long runs and careful downhill running to build specific strength while avoiding injury.
Another example: The Imogene Pass Run features a 10-mile, 5000 ft ascent followed immediately by a seven-mile 4000 ft. technical descent. Runners of this race need to practice long, steep, rocky descents on tired legs.
The same idea holds true for your running surface: sand, pavement, snow, gravel, sloped roads, etc. All of these surfaces place unique demands on your muscles. Train appropriately for the specific demands of your race.
Resist With Strength
Strengthening of cramp-prone muscles can help them resist cramping. Strengthening supporting muscles will also help reduce the workload of cramp-prone muscles. You can choose from many exercises to gain this strength. Here are several that emphasize key muscles that often cramp. Several of them are similar and overlap in the targeted muscles.
Advanced Tip: Do a strength training session directly after a hard run to simulate conditions under which cramping occurs. It will build your cramp-resistance in a race-specific way.
- Cramping muscles
- Squats, Single-leg squat, Hip hike, Mini-squat
- Step ups, Hamstring curl
- Adductors (groin/inner thigh)
- Step ups, Forward lunge, and most other lunges
- Glutes & hip abductors (crucial supporting muscles in hips and butt)
- Step-ups, Hip hike, Single-leg tubing squats, Mini-squat
- Standing heel raise, Mini-squat
Prior injury to cramping muscles and inadequate recovery seem to precipitate cramping. Injured muscles must be allowed to heal. Once healed, those tissues should be strengthened aggressively. Consult with a physical therapist if you suspect an injury.
Injured or not, runners should taper and rest adequately prior to races. Tapering involves running less. If you’re prone to cramps then you may need a larger and/or longer workload reduction. Tapering takes discipline. Whatever else you do during the taper, rest is the priority.
Low on Fuel
Inadequate fueling leads to early fatigue independent of any hydration or electrolyte concerns. Adequate fueling fights fatigue and may reduce cramping. Try consuming the fuel of your choice earlier and more frequently than usual. Start conservatively to avoid GI distress. Consult with a sports nutritionist for detailed instruction.
When Cramps Strike
The best way to stop cramps is to avoid them. However, there are a couple of ways to fight cramps if they strike.
Stretching is effective at temporarily calming the angry muscle. You probably already do it when you get a cramp. Contract the opposite muscle to make the stretch more effective. For example, contract your quads while stretching a cramped hamstring.
While research is limited, pickle juice shows promise for curing muscle cramps. Mustard may have the same effect. The vinegar in both substances is probably the key. The process isn’t fully understood, but the idea is that the vinegar stimulates certain receptors in the mouth that trigger a neurological reset of cramping muscles. Weird? Yes, but there is significant anecdotal evidence that it works.
But rather than focus on race-day cures the best ways to avoid cramps are specific training, strength training, and adequate tapering, plus proper pacing and fueling.