Exercise Associated Muscle Cramps
by Doug Stewart
Over the years, many researchers have investigated muscle cramps caused by exercise. Whilst many theories exist on their causes, such as dehydration, muscle fatigue, weakness or imbalance, we have not yet reached a clear understanding as to what exactly brings them on.
A recently published paper, An Evidence-Based review of the Pathophysiology, treatment and Prevention of Exercise-Associated Muscle Cramps, investigated the current research on exercise associated muscle cramps and provides a comprehensive review of the current understanding of them.
Exercise associated muscle cramps (EAMCs) are defined as involuntary contractions of muscles, that occur during or shortly after exercise. They are painful and the muscles that are most commonly impacted are those used when exercising and typically span multiple joints.
Whilst, previously, research often focussed on a single reason/trigger for the cause, the review paper looks at each of the commonly researched areas, such as dehydration, and concludes that recent evidence implies that EAMCs come on due to a combination of extrinsic and intrinsic factors – rather than because of one single cause.
They suggest the following model to understand their causes:
Multifactorial theory for pathogenesis of exercise-associated muscle cramps (EAMCs). Dashed arrows used to help with clarity of understanding the hot, humid, or both environmental conditions and repetitive muscle exercise pathways. Originally printed in Miller KC. Exercise-associated muscle cramps. In: Adams WM, Jardine JF, eds. Exertional Heat Illness: A Clinical and Evidence-Based Guide. Springer; 2020:117–136
Source: Miller et al., 2022.
They then assessed the research of common prevention strategies. These include:
- Stretching (which they describe as the fastest and most effective treatment for an active EAMC). No research exists that has explored the most effective form of stretching, but static stretching seems the most used;
- Rehydration (but stretching will likely alleviate EAMCs faster than drinking will, as it takes around 15 minutes or longer for fluids to be absorbed in the body);
- Pickle Juice/Sour Drinks/Spicy Foods - There is limited evidence in this area, but some positive findings do suggest that these may help reduce the duration or severity of cramps;
- Bananas (no evidence to support their use);
- Quinine (they advise against using this for cramping).
Their review in general shows how individualised these cramps can be and how difficult it is to identify their cause. Moreover it highlights that preventative strategies to stop them from occurring and effective means to stop them quickly when they do come on are again likely unique to each individual. The researchers conclude:
“Strong evidence supports EAMC treatments that include exercise cessation (rest) and gentle stretching until abatement, followed by techniques to address the underlying precipitating factors. However, little patient-oriented evidence exists regarding the best methods for EAMC prevention. Therefore, rather than providing generalized advice, we recommend clinicians take a multifaceted and targeted approach that incorporates an individual's unique EAMC risk factors when trying to prevent EAMCs.”
Miller et al., 2022
So, if you are someone that suffers from EAMC, I highly recommend reading the paper in detail as a first point to try and help find a strategy that works for you.
References:
Miller, K.C., McDermott, B.P., Yeargin, S.W., Fiol, A. and Schwellnus, M.P., 2022. An Evidence-Based Review of the Pathophysiology, Treatment, and Prevention of Exercise-Associated Muscle Cramps. Journal of Athletic Training, 57(1), pp.5-15.