What are Exercise associated muscle cramps?
Exercise associated muscle cramps are defined as a painful involuntary contraction of s skeletal muscle during or just after exercise (Schwellnus et al (2004). The cramping normally occurs in muscles that cross over more than one joint with the most common culprits being gastronomies + soleus (Calf) followed by the hamstring and quadriceps (Rectus femoris). Cramping from exercise is incredibly common with 67% of triathletes complaining of cramping during training sessions. Kantarowski et al (1990). There are also a lot more common in endurance sports and normally happen towards the end of the session or event. Therefore it won’t surprise you fatigue is one of the main risk factors in developing a cramp.
Symptoms of cramps:
It may seem obvious but I’ll explain it anyway:
- Pain often extreme and often debilitating in nature
- Sudden pain often with no warning
- Tight contraction of muscle
- Visible tightening or knotting of muscles
- Cramp Prone State or General muscle after a cramp, which can last up to 8-48 hours after the initial cramp.
Causes of cramping:
Neuro-muscular control/ fatigue:
The view of neuro-muscular control being the cause of exercise-associated cramps is that the overload and neuromuscular fatigue causes an imbalances between the spindles in the muscle fibres and their inhibitory electrical impulses from the Golgi tendon organs. An increase in the intensity of the electrical impulses can cause an increase in chemicals in the muscle fibres, which induced the muscle camp. (Schwellnus et al 1997) This often occurs in muscles that are already tense or contracting. There are numerous studies that show an increase rate of cramps at the end of competition or physical exercise when the muscle is already tight or shortened. There are limitations to this theory may of which centre around how much fatigue is necessary to induce a cramp and it some seem to differ depending on each athlete. Other research to support this theory is that it is more common to get cramping in longer endurance events as well as events that are done at a higher intensity or speed.
Electrolyte imbalances have always been the traditional and most common known causes of the cramping. (Stone. 2003) However the recent evidence is starting to stack against this in being the actual cause of the condition. The theory is that if you don’t take in enough water to replace the amount of fluid and electrolytes that you will lose through seating it can result in sensitisation of the nerve ending. These nerve ending will contract and in doing so increase the pressure and force the muscle produces which leads to the cramping (Bergeron, 2008). However may argue that it doesn’t offer plausible pathophysiological mechanisms through research. While this make sense and there is research to back this up in groups such as miners or footballers training in hot conditions it doesn’t explain cramping in athletes that get cramps in cool or temperature control conditions such as a gym. Furthermore research shows no difference in sweat rate or salt or fluid losses in athletes that do and do not get cramps. (Stofan et al 2005)
Studies by (Braulick et al 2013) tested this theory by inducing 10 people into being extremely dehydrated on average they measured at being 4.7% dehydrated after 4 hours of exercise in extreme heat when 5% is counted as seriously dehydrated. Despite the severe amount of dehydration and 4g of salt that they did loose there was no difference in the intensity or risk of getting a cramp.
So what does this mean?
It seems that the as the onset of exercise induced cramps can occur in many different circumstances and conditions that its mostly like that the cause is often a combination of different causes rather than just one singular cause. Miller et al (2010). There are also said to be many predisposing factor to why some people suffer with cramps including genetics, fatigue muscles, starting too fast or not tapering efficiently and therefore being more fatigued. If you are susceptible to cramps write it down, log your training and record when you get the cramps and see if there is a pattern to why you are getting fatigued. What was the weather like, did you hydrate and fuel correctly and see if there is a correlation, the more information you have the more you’ll be able to spot any potential problems.
Treatment for cramping:
In this case salt is your best friend, the recommendation by the national athletic trainers association recommends adding 0.3-0.g to your drink to prevent came, though others have quoted much higher. You can go for cells or sports drinks but read the label as many have more sugar and very few electrolytes in them. (Binkley et al, 2002) Also don’t expect instant results it will take around 13 minutes for it to get absorbed into your blood stream. You can get injections of salt water into the muscle for cramps but this is rather rare and normally only found at higher level.
In extremely rare cases you can use benzodiazepine to chemically relieve cramps though I have never heard of this actually being put into practice.
Stretch it out. This is common knowledge and advice but actually why does everyone always say this? Stretching is thought to relieve muscle camping by inhibiting the muscles that is already tight, as it will increase the tension in the tendon increase the feedback to tell the muscle to relax which should work to restore the physiological relationship between the chemical impulses in the muscle, which causes it then to relax.
How to prevent cramping:
While there is lack of evidence for the dehydration electrolyte theory its still a good idea to make sure you are fully hydrated. At the end of the day its not going to do you any harm in the long run anyway. You want to make sure you have 1L of liquid before you do exercise to be hydrated, in tennis it has been recommended to have 1.8L in athletes that are prone to cramps. Bergeron (1996) There is evidence by Jung et al 2005 that shows that having a carbohydrate-electrolyte drink before and throughout a workout especially in warm conditions can prevent the onset of cramping in athletes however 69% of the people tested still got cramps despite being efficiently hydrating.
Similar to what I have already mentioned in the treatment section stretching is key to preventing cramps especially if you can get someone else to help you. Stretching should help increase the blood flow to the muscles and therefore help in getting rid of the harmful metabolites that will build up in them. For more information on how to get the most out of your warm up look at my previous blog post. The idea of a warm up is to increase your body temperature slowly and prepare your muscle for the activity that your about to do. Another factor that can induce cramping is changes in weather and temperature so make sure you warm up properly to avoid this and slowly increase your body temperature. So make it specific and switch it up make sure it consists of active stretches and drill not just ones where you are standing still.
Adjust your training:
As fatigue is seen to me the major contributing factor to getting a cramp its important to have a look at your training schedule make sure you aren’t overdoing things. This includes building up the mileage slowly week by week around 5-10% is enough don’t go above this. Make sure you vary the intensity as well if you are doing numerous runs in a week make sure there is a combination of recovery, long runs and well as more intense fartlek, speed or hill runs. Also make sure that you practice your race pace especially for longer events to make sure that your body is prepared for the race itself. The more you vary the running the more you will recruit different muscles different amounts which should leave them more time to recover.
Recovery and rest days are soo important!! Make sure you do try to have a day off in between runs especially if they are of high intensity, even if you have an active recovery don’t be tempted to exercise your legs to much work on your core instead. Try to incur-operate at least two rest days into your week. Add some strength and cross training into your schedual cross training is a great way of increasing and maintaining your fitness while giving your muscles a bit of a break try swimming or a spin class instead to try and switch things up. The stronger your muscels are the longer they are likely to last before they will fatigue so its important to increase muscle weakness and stretch out tight muscles so they are able to achieve their maximum.
Try to make sure you have enough fuel in the tank before your workout. You want to have a diet full of lean protein and complex carbs such as wholemeal with some fats. Blood sugar levels have been seen to be a contributing facto into cramps so make sure you get enough complex carbs that will slowly release energy to prevent a sugar spike.
Similar to stretching massage can help to reduce cramping. You can read more about the benefits of a sports massage on my previous blood post. However the idea is to reduce the tone of the muscle in order to help increase the range of movement possible at the joints. This is turn should mean your muscles don’t have to work as hard to achieve the same range of motion. The increase blood flow will also aid recovery and reduce fatigue.
Having good form:
It might not surprise you but the more efficient you do whatever task or workout the less you are going to demand from your body. In the case of cramps this is linked to fatigue, I would like to see anyone who has the exact same form at the beginning of a workout to 45 mins in to it. As you fatigue your form will tend to slip and then in turn your already tired muscle will work harder. Obviously there is only so much you can do to prevent this, it’s human nature so just try and focus on increasing your stretch and your aerobic fitness.
Stofan J, Zachwieja J, Horswill C, Murray R, Anderson S, Eichner E. (2005) Sweat and sodium losses in NCAA football players: a precursor to heat cramps? Internation Journal of Sports Nutrition Exercerise Metabolism 15:641-652.
Jung, A. P., Bishop, P. A., Al-Nawwas, A., & Dale, R. B. (2005). Influence of Hydration and Electrolyte Supplementation on Incidence and Time to Onset of Exercise-Associated Muscle Cramps. Journal of Athletic Training, 40(2), 71–75.
Schwellnus, Nicol, Laubscher, Noakes (2004) Serum electrolyte concentrations and hydration status are not associated with exercise associated muscle cramping (EAMC) in distance runners British Journal Sports Medicine 38:4 488-492 doi:10.1136/bjsm.2003.007021