What is a Cramp?
A cramp is an involuntary muscle contraction. This can range from a small twitch in the muscle to a complete lock-up. Cramps can be mild, or they can be intensely painful and hard to release. In some cases, they are relatively easy to work through and continue to exercise. In others, they can be debilitating and put an immediate stop to your event. Cramping is common in many activities, but runners are particularly susceptible. Running provides a perfect blend of physiological stress which may lead to cramping.
Depending on the situation, a cramp can be caused by one or many things. This has provided a breeding ground for marketing claims which jump on several mechanisms potentially ‘cured’ by a certain product. In order to truly prevent cramping, one must look at the full picture and identify what factors are at play and to what degree. Then they need to be addressed appropriately.
Cramping is generally considered to be a neuromuscular issue. The muscle contraction is initiated by neural signals which are sent via chemical gradients. How we transmit, receive and react to these signals are all locations of where cramps can be initiated. As we exercise, these chemical gradients can change in how they take effect. In some cases, fatigue causes these signals to have a heightened impact, known as increased excitability. In others, as muscles become fatigued and perhaps even damaged these signals can have less effect. In either case, contractile function changes. If it shifts to extreme we may suffer a cramp.
To prevent muscle cramps, it’s important to understand some of the causes so you can employ mitigating or preventative strategies. From here you can identify which possible cause you might be susceptible to, and it will highlight what strategies will be most effective and practical.
What Causes Muscle Cramps While Running?
1. Exercise Intensity
When we work hard and at a high intensity we place our muscles under stress. When they are stressed, they may start to become damaged and fatigued. This damage causes leakage of fluid which results in the loss of chemical gradients which are essential to receiving and responding to nerve signals. In addition, structural damage occurs which can cause an inflammatory response which results in pain. Muscles may not contract and relax as well as they should. When we overwork a muscle to the point at which it becomes damaged, it may cramp, as it simply cannot respond effectively to the signals being sent to it. The added impact and vibrations that occur during running can contribute to this damage over time. In isolation this is what causes soreness after exercise. This is known as delayed onset muscle soreness (DOMS). The repair and recovery from this stress makes us stronger and more resilient in future.
In addition to the physical strain we place on the muscle fibres during exercise, they also produce heat. Heat causes chaos in the cells which must operate in a tightly controlled temperature range before essential enzymes and reactions begin to fail. Our bodies put great efforts into regulating temperature. Evaporative cooling is the main mechanism here and this is achieved through sweating. Our sweat comes from the plasma in our blood, so as we sweat our plasma volume falls. If this happens our heart must work a little harder to get blood around the body. The end result is that oxygen delivery becomes more of a task. Additionally, in order to sweat, blood must move to the extremities of our body meaning there is greater competition for blood supply with the skin, muscle and vital organs needing their share.
2. Hydration Status
If we are working hard, regardless of the environmental conditions, we need to regulate heat. In hot conditions this is even more so the case. How much we sweat can be misleading, as in humid conditions sweating is less effective and it might seem to be more intense. In warm dry conditions we might not even realise we are sweating as much as we are because it is evaporating as it should and we might feel dryer. Hydration, therefore, becomes a very important factor. Not only is it important for providing the fluid for sweat but it is also required to sustain plasma volume and facilitate blood flow to where blood is needed.
3. Electrolyte Imbalances
When we consider sweat, we also begin to think about electrolytes. The main electrolyte involved in sweating is sodium. Generally, the sodium concentration of sweat is similar to that in the blood. So, the loss of fluid and sodium is generally matched well enough for concentrations in the blood to remain stable. This is contrary to what many believe. When we start to consume fluid we now re-introduce fluid without the necessary sodium. So, if we are losing fluid and sodium continuously through sweat but only replacing the fluid, quickly an imbalance will develop. This is when issues may start.
The first investigations of electrolytes and their involvement with cramping were made in miners working in hot conditions where they were sweating at very high rates. Despite consuming water, they would experience debilitating cramps. In one mine, a doctor had the theory that this was due to loss of sodium. He instructed the miners to add salt to their meals and soon they found the incidence of cramps began to decrease. This became the basis for sodium to gain such attention in regard to cramp. As a result, there are quite a range of sodium related products aimed at hydration and as a potential cure for cramping. In addition to sodium, magnesium and potassium also play roles in healthy muscle function. However, when cramps appear there does not seem to be much depletion of magnesium or potassium in comparison to sodium. Losses of these electrolytes tend to occur more so in the case of illness rather than exercise.
How Much Sodium Do We Need?
This will differ between one individual to another and depends on a variety of factors including genetics and sex. The range of potential sodium losses can be quite large. Generally, more sodium in the diet will also result in greater amounts of sodium lost through sweat. Sodium in the diet can create concerns for blood pressure in some individuals, which must also be considered, although this is less of a concern in highly active athletes.
The typical 330ml bottle of most commercial sports drinks contains about 150-250mg. However, individuals can lose up to 5000mg in a single bout of exercise. There are several ways to estimate fluid and sodium losses during exercise and sweat testing may be something worth committing to if you suffer from muscle cramps often. Needless to say, an effective hydration strategy which considers sodium needs can not only help prevent cramp but also have a profoundly beneficial impact on exercise performance.
Putting these Together
If you consider a race day, you have adrenaline, excitement and motivation added to the mix. Suddenly, you are putting your body on it’s limits. You will strain the muscles and you are likely to get hot; you may also become easily distracted from hydration and fuelling. If you do not support your body, it will be under increasing strain as it loses fluid, becomes less effective at regulating heat and meeting oxygen demands. You may also find that while you have trained at race pace, you may not have sustained race pace like you need to in an actual race. The recoveries you build into the training plan are now absent. You don’t have time to slow down. And so, the risk of cramp is massively increased.
Top 9 Ways to Prevent Muscle Cramps While Running
1. Build Fatigue Resistance Through Gradual Training
- Increase weekly mileage slowly
- Use tempo and subthreshold training to effectively build your tolerance to stress and improve muscular endurance and fatigue resistance.
2. Strengthen Key Muscles for Running Stability
- Strength training makes the muscle fibres more resilient to stress and can prevent excessive damage from occurring.
- Strength training can also help develop motor skills which lead to improved running economy.
3. Improve Running Form & Cadence
- Your running style is hard to change; however, small technical optimisations can prevent muscular imbalances which cause strain and injury.
- Learning to run with your body can help improve economy and this is something that comes with training and experience.
4. Dial in Your Hydration Plan
- Make efforts to develop a personal hydration strategy and practice it for race day.
- Learn to be diligent with hydration and recognize when adjustments are needed to the amount and constituents of your hydration formulas.
5. Balance Electrolytes: Sodium, Potassium & Magnesium
- Know what’s enough for you and what you can tolerate.
- Practice your strategy so you know what is most appropriate and effective over your chosen distance.
6. Fuel Properly with Carbohydrate During Longer Runs
- Depleting glycogen stores results in muscle fatigue and creates more stress. You must fuel for the work required.
- 60g/hr is the recommended minimum for training or racing. Practice this and have a strategy.
- Know the demands of your distance and plan for this logistically through aid stations and what you can carry with you.
7. Warm Up the Right Way
- Ensure that you increase muscle temperature to its optimum, pre- race. This might also involve staying cool pre-race in extremely hot conditions.
- Complete a warmup that brings you up to race intensity, so the muscles are prepared for the work to come.
8. Stretch & Mobilise Regularly
- Muscles gather tension when being used regularly. Preventing tension build-up can help prevent imbalances and strains.
- Some regular gentle stretching and dynamic warmups can help maintain muscle quality and adequate ranges of motion.
9. Pace Smartly on Race Day
- Going too hard off the start is common with excitement. Have a plan and have confidence to stick to it.
- Settle into your pace and avoid surges if they aren’t needed; this will save the legs for a final push.
What to do if you get a Cramp Mid-Run ?
Slow down and allow yourself to recover on the move. It may be a transient cramp that passes if you let it. Walk if needed.
Light Stretching can help break out the tension of a cramp and allow you to settle back into your pace. Try to do this on the go if you can, so you don’t lose more time than needed.
Foods, Supplements & Hydration Tips for Cramp Prevention
1. Sodium Capsules and Chews
These can be a convenient way to top up sodium over longer distances and can be stored in such a way that you can save them for another race if you don’t need them. Sodium chews are also an option and due to their tart taste, they can encourage drinking. This is especially helpful if you have been consuming a lot of sweet carbohydrates and your taste buds are fatigued.
2. Sports Drinks
Replacing fluids and sodium with some carbohydrate will help fluid get absorbed faster. Often pre-bottled sports drinks are less sports orientated around sport and more for general consumption with a sporty vibe, so using more specific formulas from reputable sports nutrition brands in your own bespoke concentrations is often a better option.
3. Pre-run Hydration Habits
Having adequate hydration pre-race can help alleviate the impacts of fluid loss. Consuming fluid with adequate sodium can help you retain this fluid.
Common Mistakes Runners Make That Lead to Muscle Cramps
1. Overtraining
Many runners enter a race more fatigued than they realise and the muscles may already have some latent strain that induces cramp earlier than normal. In addition, tight tired muscles already carry tension which compromises contractile function. One might be more susceptible to cramp in this situation.
2. Racing Under-Fueled
Many runners fail to acknowledge the energy demands of long intense races. They might also neglect how much their training can deplete their glycogen stores pre-race. Recent trends towards high fat low carb diets have also become more common in runners. Glucose is essential for maintaining race intensity; without it the muscle is placed under additional stress which accelerates the development of fatigue, contributing to the outcomes above.
3. Ignoring early fatigue
It may seem obvious, but race day excitement and motivation can cause people to exceed their ability or neglect their plan. In many cases where cramp occurs it is simply a case of people overestimating their ability and ignoring the fact. Excessive strain early in the race comes at a cost.
Frequently Asked Questions
Why do I get calf cramps when running?
The calves absorb a great deal of force when the foot strikes the ground. They must absorb a lot of eccentric force which over time causes damage and a loss of contractile function. They are prone to cramps simply because they are worked quite hard during running.
Should I stretch before running to prevent cramps?
Stretching is unlikely going to prevent cramps if other factors are not addressed. However, stretching can maintain muscle function and range of motion which may promote good movement mechanics and running economy.
Why do I get stomach cramps when I run?
Stomach cramps are due to a reduction in blood supply to the gut. When combined with fluid or food intake this places strain on the lining of the gut which may initiate signs of gastrointestinal stress including cramping.
How to stop stomach cramps when running?
Acute cramps can be helped with a reduction of intensity and consumption of food and fluid, although sometimes plain water may help alleviate symptoms depending on the cause. The gut can be trained for its tolerance to food and fluid intake during exercise.
Do dehydration and heat increase cramp risk?
Absolutely, and alongside exercise intensity these are the main factors in the development of cramping.
Should you push through cramps?
Pushing through cramps will cause further damage to the muscle. Minor strains may occur as a result and are likely to result in DOMS, however pushing to the extreme can have serious consequences with more frequent reporting of rhabdomyolysis during running events, a potentially serious situation.
Do bananas help with cramps?
Not significantly, although they do contain nutrients which can help support your training.
Conclusion
Cramping can change the course of your race quite significantly and suddenly. Many cramps can be prevented through adequate race preparation and execution. Ultimately, conditioning is the single biggest preventative factor. The more conditioned you are to high intensity, volume and duration of exercise as well as exposure to similar race environments, the less likely you are to have a problem. However, if you are going to take your body to its limits you need to support it with what it needs to perform. Experience plays a large part in combining these elements and preparation can provide the lessons that help you avoid and manage cramps when it matters most.