Cramps are extremely common among endurance athletes, with studies suggesting that cramps affect up to 67% of triathletes during or after training or racing and between 18–70% of marathoners and cyclists¹.

A cramp is a temporary but intense and often painful involuntary muscle contraction that can occur in many different situations, with various potential causes. When experienced during training or a race, this often debilitating condition is referred to as exercise-associated muscle cramping (EAMC). These cramps are characterised by an unpredictable onset, with variable intensity and duration.

EAMC is often seen during sports and rigorous exercise or physical activity in hot and humid conditions². In these situations, the underlying pathologic mechanism is usually a substantial loss of sweat and electrolytes.

A study³ published in the Journal of Athletic Training, confirmed the influence of hydration and electrolyte supplementation on EAMC, with researchers concluding that drinking “a carbohydrate-electrolyte beverage before and during exercise in a hot environment may delay the onset of EAMCs, thereby allowing participants to exercise longer.”

However, they also found that dehydration and electrolyte loss were not the only causes of EAMC because “69% of the subjects experienced EAMCs when they were hydrated and supplemented with electrolytes.”

That means conventional guidelines around fluid and electrolyte intake can help to alleviate cramping in certain, but not all cases.

Another theory suggests that neuromuscular fatigue and the loss of inhibitory reflexes cause excessive muscle activity during exercise that can lead to cramps⁴.

Several studies into this theory have identified various EAMC risk factors, such as previous cramping experience⁵ (if you’ve cramped before, you’re more likely to cramp again) and higher exercise intensities⁵.

Also, neural fatigue-related cramps seem to occur most frequently in two-joint muscles like your hamstrings, quads, calves or biceps because these muscles work as antagonistic pairs – contracting one muscle requires the relaxation of the opposing one.

Essentially, as we fatigue, the mechanism that causes a muscle to contract becomes overstimulated, while the mechanism that causes muscles to relax is under-stimulated. This overstimulation results in a loss of neuromuscular control, which will eventually result in a sudden, sustained, involuntary muscle contraction – a cramp.

This type of functional muscle cramp relates to a lack of adequate training or conditioning because a muscle is unable to withstand the forces you are imposing on it. This would explain why athletes cramp during races but not necessarily during training, as they are pushing harder for longer than their muscles can sustain the effort.

Poor form or technique can also limit your range of motion, forcing a muscle to contract within a short movement range, and causing fatigue to set in more rapidly.

With different types of cramps initiated by different mechanisms, it is impractical to find a single solution to prevent or treat EAMC.

What this means is that, depending on which muscles cramp, you have a variety of potential remedies at your disposal.

The easiest issue to address is ensuring adequate hydration and electrolyte intake before, during and after training and races by using products like Biogen Cramp Care+, which supplies the full spectrum of electrolytes.

If the same muscles cramp during races, then you may need to address a strength imbalance or any movement inefficiencies or restrictions (a qualified biokineticist can address this). You may also need to review your training program to identify any possible conditioning shortfalls.

When a cramp sets in, or you start to feel the initial twitches, you should:

  • Decrease your pace or intensity to see if the cramp eases.
  • Don’t stop. Keep moving the muscle and try to extend it through a fuller range of motion.
  • Sip on a carb-electrolyte drink or a gel to see if this helps – do not drink too much, though.
  • If a cramp sets in, stretch the affected muscle with a simultaneous contraction of the opposite (antagonist) muscle to try and calm the reflex.
  • If stretching the affected muscle does not offer relief, perform a deep massage of the affected area or apply direct pressure to the knot until the muscle releases.
  1. Maughan RJ, Shirreffs SM. Muscle Cramping During Exercise: Causes, Solutions, and Questions Remaining. Sports Med. 2019 Dec;49(Suppl 2):115-124. doi: 10.1007/s40279-019-01162-1. PMID: 31696455; PMCID: PMC6901412.
  2. Noonan B, Bancroft RW, Dines JS, Bedi A. Heat- and cold-induced injuries in athletes: evaluation and management. J Am Acad Orthop Surg. 2012 Dec;20(12):744-54.
  3. Jung AP, Bishop PA, Al-Nawwas A, Dale RB. Influence of Hydration and Electrolyte Supplementation on Incidence and Time to Onset of Exercise-Associated Muscle Cramps. J Athl Train. 2005 Jun;40(2):71-75. PMID: 15970952; PMCID: PMC1150229.
  4. Schwellnus MP. Cause of exercise associated muscle cramps (EAMC)–altered neuromuscular control, dehydration or electrolyte depletion? Br J Sports Med. 2009 Jun;43(6):401-8. doi: 10.1136/bjsm.2008.050401. Epub 2008 Nov 3. PMID: 18981039.
  5. Schwellnus MP, 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. Br J Sports Med. 2011 Jun;45(8):650-6. doi: 10.1136/bjsm.2010.078535. Epub 2010 Dec 9. PMID: 21148567.