Exercise-induced calf cramping occurs primarily due to neuromuscular fatigue. Nocturnal leg cramps, leg cramps at night, can also occur due to fatigue but can also occur due to inadequate hydration/electrolyte balance (known as homeostasis).
This article will deal with exercise-induced calf and leg cramps. Nocturnal leg cramps will be the subject of another post at a later date.
Why do calf & leg cramps happen?
The sustained strong activation of the calf that occurs with calf cramps causes muscle damage, in particular to the connective tissue within the muscle.
In normal muscle function, electrical impulses from the nerve reach a threshold that triggers the muscle firing.
During cramping, the threshold needed to trigger the muscle is reduced. Additionally the nerve signals from the spine are altered. This causes the muscle to fire easily, with a very strong contraction that often sustains for a few seconds.
With a strong contraction, the connective tissue linking the muscle fibres is strained. This causes small amounts of damage over a broad area.
Fixing calf & leg cramps
There are a number of types of muscle cramps, coming from a variety of cause. Each type has a different treatment. And this is where much confusion originates with effective cramp fixes.
For exercise-induced calf cramps, we’ll cover prevention of calf cramps, relieving calf cramps and recovering from post-cramp muscle damage.
Preventing calf & leg cramps
Calf cramps during exercise are caused by neuromuscular fatigue, with contributing factors such as heat and restrictive clothing.
The trick to preventing cramping is in your prep work.
Strength training will delay neuromuscular fatigue. It may not prevent cramps completely, but you’ll be able to go significantly longer before they start.
Avoiding excessive heat will also reduce your chance of cramping. In some situations, you can change your training schedule to avid the heat of the day.
Another contributor to heat is inappropriate clothing options. Wearing thick clothing or compression garments on hot days can increase the skin surface temperature by up to 5 degrees Celsius.
Importantly, consuming electrolytes or salts does not prevent exercise-induced cramping. This myth has been spread widely over the years but has no merit. (NB. There are cramps associated with low electrolyte levels but these cramps affect all muscles simultaneously and are a medical emergency, not isolated calf cramps).
Relieving calf & leg cramps
Once the cramp takes hold, you’ll need to get it to release as quick as possible. This will minimise muscle damage and eases the pain.
Stretching is the most common approach to easing cramps. But it’s vital to note that the stretching should be mild to moderate, not strong stretching. With the muscle contracting so violently, forceful stretching back the other way only adds to the damage.
The other trick is salty foods and drink. You don’t need to ingest it, only taste it.
The salty taste on the tongue is enough to trigger a response from the body and alleviate the cramp.
So ingesting a salt capsule, which doesn’t give a salty taste, isn’t as effective as crushing it in your mouth, swirling it enough your mouth them spitting it out.
Cramp sprays are popular as well, but remarkably ineffective. They work by cooling the muscle but that’s only helpful if heat is a cause.
Lastly, stopping. Just stopping your activity will help the cramps ease as it gives the muscle a chance to recover from fatigue. But avoid taking the pressure off the foot completely as a lack of muscle resistance can add to the cramping impulse.
Recovering from muscle damage caused by calf & leg cramps
You’ll need several approaches to rapidly recover from post-cramp pain.
Then massage or gentle foam rolling can manage the symptoms to assist with a return to normal walking. Wait for 24 hours after the cramps before commencing this approach.
A return to exercise needs to be gradual and can commence from 3 days post-cramping.
Start with steady walking on flat ground. Once that’s comfortable, begin to add speed to your walk. Next you can try walking on inclines before finally trying a return to running (see our guide on safely building your running distance).
Avoid strength exercises for at least two weeks post-incident. Strength work tends to prolong the recovery and can potentially trigger further cramps.