Exercise Associated Muscle Cramps
Strength training to combat Exercise Associated Muscle Cramps (EAMC)
S&C trained cyclist Lee Scurlock tackling the highest mountain bike race in the world; Yak Attack Nepal…..cramp free
We have all been there … or know an athlete who has. We have (in theory) nailed our nutrition and training plan, however come race day we find ourselves plagued with exercise associated muscle cramps (or EAMC).
So, what exactly are EAMC’s, why do they happen and what can we do as athletes to reduce the likelihood of experiencing them?
EAMC’s occurring in recreational and competitive athletes are defined as painful, spasmodic and involuntary skeletal muscle cramps that occur during or shortly following exercise in healthy individuals with no underlying metabolic, neurological, or endocrine pathology[i]. They tend to be more prevalent in athletes undertaking endurance sports, or sports that that last for extended duration with high intensity bouts. They also typically occur in muscles that are subjected to high contractile demand during exercise exertion (think soleus for runners & hamstring & quadriceps for cyclists). While the underlying cause of EAMC’s are not well understood, there are a number of factors that are believed to increase an athlete’s susceptibility.
Let’s start with electrolyte imbalance and dehydration.
Many of us have been told that to ‘fix’ EAMC we need to hydrate better and increase our electrolyte consumption …for those who know let’s cue the pickle juice & salt tablets.
However, a study by Schwellnus (2011)[ii] compared dehydration variables, serum electrolytes and muscle damage serum markers between 210 Ironman Triathletes who suffered EAMC and those who did not. The study measured pre-race and post-race markers by reviewing blood samples of the athletes that identified serum electrolyte concentrates. 43 triathletes who reported experiencing cramps were compared with the 166 who did not cramp.
Interestingly there were no significant differences between groups in any pre-race-post-race serum electrolyte concentrations and body weight changes.
Therefore, the study concluded that the development of EAMC was associated with faster race times and subsequent onset of muscle fatigue and muscle damage.
So, if we deep dive a little further let’s explore another study that looks at the role that muscle damage serum markers play in EAMC’s.
A recent study by Martinez-Navarro et al [iii] went one step further and compared muscle damage serum markers, serum electrolytes and dehydration variables between runners who suffered EAMC and those who were cramp free during a marathon. They similarly reviewed:
· Pre and post-race blood samples
· Urine samples
· Body mass.
They found there were no differences in body mass ( i.e. dehydration did not play a role), post-race urine specific gravity, and serum sodium & potassium concentrates (i.e. electrolytes did not play a role) between athletes that cramped and those that didn’t.
Once again confirming electrolytes and dehydration are not believed to play a significant role in muscle cramps.
What is interesting however is that they found athletes who suffered EAMC exhibited significantly greater post-race creatine kinase and lactate dehydrogenase- simply put these are some of our key markers for muscle damage. Furthermore, 48% of the non-cramping group reported that they undertook regular lower limb strength training, while only 25% of the cramping group doing the same.
Which leads us to ask…is it likely a coincidence that those athletes that undertook sport specific strength training had a significantly lower affliction from EAMC’s???
We don’t think so.
Simply put, the above review concludes that contrary to popular belief, muscle cramps have nothing to do with electrolyte loss or dehydration, rather they can be linked to muscle load and associated fatigue (i.e. muscle damage and the athletes ability to delay/prevent this).
This becomes increasingly interesting when we look at athletes’ understandings of cause and possible prevention. A survey of 344 endurance athletes found that 75% believe that consuming extra sodium can help prevent muscle cramps[iv]. Which we now know has been repeatedly debunked in numerous case studies.
So what does that mean?
Can strength training be a preventative measure for EAMC’s?
Yes!
As we now understand, cramps typically occur in muscles that are fatigued to the point of damage. Specifically, when a muscle is extremely tired, mechanisms within the muscle start to misfire ( say hi to our Golgi tendon organs and muscle spindles!**). When a muscle becomes increasingly fatigued, it’s believed that the Golgi tendon organs are unable to prevent the over activity of the muscle spindles causing the muscle to contract uncontrollably.[v]
Therefore, to prevent the onset of the muscle fatigue sport specific strength training and plyometric exercises may be the most effective conservative method to prevent EAMC onset[vi].
Our advice for athletes;
1. If you experience EAMC make note of what muscles are cramping and when the cramps usually onset during your training or racing ( get familiar with your body, review training load and journal about your training and anything that impacts it)
2. If you are not already, begin to prioritise strength training for these muscle groups…. Ideally work out what muscles play a key role in your sport and start training them regularly under load. With appropriate strength work we see improvements in increase time to exhaustion, force production, improved strength endurance, improvement in force transfer, improved power, reduced injury risk, improved coordination. All of these play a role in reducing the onset of fatigue related critical muscle damage leading to EAMC’s
3. Include plyometric training in your weekly plan to assist with neuromuscular control, force absorption and explosivity
4. Focus on unilateral movements – this helps to balance out muscle imbalances which often is linked to increased EAMC in athletes due to increase in load being absorbed by one side (if EAMC’s plague the muscles of your lower leg get comfortable with your single leg leg press, lunge variations, pistol squats and single leg step ups)
5. Lastly, if in doubt or wanting any more info on performance reach out at https://www.dynamicah.co/ or find us on socials
** Golgi tendon organs ( located in tendons)= Primary role is to review tension in a muscle and inhibit overstimulation when fatigue or overload occurs
** Muscle spindles (located in muscle belly) = detect the change in length of a muscle and signal contraction.
Lauren Lander
Accredited Exercise Physiologist
Dynamic Allied Health
[i] Schwellnus M, Derman E, Noakes T. Aetiology of skeletal muscle “cramps” during exercise: a novel hypothesis. Journal of Sports Science. 1997;15:277-285 (Pubmed)
[ii] Schwellnus M, Drew N, Collins M. Increased running speed and previous cramps rather than dehydration or serum sodium changes predict exercise-associated muscle cramping: a prospective cohort study in 210 Ironman triathletes. British Journal of Sports medicine.2011; 45(8):650-6
[iii] Martinez-Navarro, Montoya-Vieco A, Collado E, Hernando B, Panizo N, Hernando C. Muscle cramping in the marathon: Dehydration and electrolyte depletion vs muscle damage. Journal strength & Conditioning Resources. 2022 June 1; 36(6) 1629-1635.
[iv] McCubbin AJ, Cox GR, Costa RJS. Sodium intake beliefs, information sources, and intended practices of endurance athletes before and ruing exercise. International Journal of Sports Science Nutrition and Exercise Metabolism. 2019 July 1;29(4) 371-381
[v] Miller KC, Stone MS, Huxel KC, Edwards JE. Exercise-associated muscle cramps: causes, treatment, and prevention. Sports Health. 2010 Jul;2(4):279-83
[vi] Nelson NL, Churilla JR. A narrative review of exercise-associated muscle cramps: Factors that contribute to neuromuscular fatigue and management implications. Muscle Nerve. 2016;54(2):177-185.