Your pedal stroke resembles David Millar’s, your cardiovascular and muscular systems are calmly working in effortless harmony and, to your surprise, you’re in the flow. Next step, WorldTour you ponder, a self-satisfied grin stretching across your chiselled visage. And then it happens. Humility returns in an instant with an “aaaarrgggghhhh”. You leach power, come to a standstill and struggle to dismount as it’s happened: cramp has struck. Again.
Your only crumb of cramping comfort is that it happens to the best of them. A bout of cramp saw Arkea-Samsic’s Dorian Grondin go backwards at this year’s Criterium du Dauphine, leaving the then King of the Mountains sitting and stretching on the grass verge. Usain Bolt’s career concluded not in glory but with an episode of cramp in London, 2017. And Carlos Alcaraz cramped up in this year’s French Open semi-finals against Novak Djokovic, citing tension and nerves.
Cramp is democratic, striking anyone at any time. But what exactly is it? And how can you improve your chances of sidestepping the spasm? Read onto find out…
What is cramp?
“Cramp is a muscle contraction that doesn’t relax,” explains Steve Johnson, exercise physiologist and the president of USA Cycling from 2006 to 2015. Let’s dig a little deeper with our theoretical muscle biopsy. “The relaxation part of a contraction involves molecular action between myosin and actin. [Myosin is a protein that converts chemical energy in the form of ATP into mechanical energy; actin’s also a protein and, as you can see, involved in muscle contraction.] In essence, a molecule attaches to myosin and then the head pivots and pulls it forwards, so it’s constantly reaching out and pulling the muscle to make it shorter.
“In order to relax and recock, to let go of the muscle, that’s where the energy is actually used. However, if your muscle runs out of energy – glycogen, typically – it doesn’t have the energy to let go of the molecule so they stay stuck together. So, when it contracts it stays contracted.”
That’s the physiology and often comes at the end of a long, hard day in the saddle when your battery’s depleted or you’ve been riding in the heat. And that means pain, often deep, deep pain. In 2019, legendary exercise physiologist Ron Maughan co-authored a review article in the journal Sports Medicine entitled ‘Muscle Cramping During Exercise: Causes, Solutions and Questions Remaining’. In it, Maughan detailed what we all know: that the pain spectrum of cramping is wide one.
“The intensity and duration of cramps can vary greatly, from a minor spasm that resolve spontaneously within a few seconds, to the whole-body ‘lock up’ lasting several minutes that some athletes describe,” Maughan wrote. “In severe cases, the muscle pain may persist for hours or even days after the acute contraction has resolved and may result in an inability to train or compete. At worst, repeated episodes can result in a premature end to an athlete’s career.”
Arkea-Samsic’s Dorian Grondin suffered bad cramp during the Criterium du Dauphine (Image by Getty Images)
Rouleur’s crew collectively spasm
Ever inclusive, we put a Twitter callout to determine the extent of Rouleur’s readership’s debilitating dalliances with cramp. The feedback snapshot… Malcolm Bradbook: “Made it up the Tourmalet and Hourquette and then had 60 undulating miles before Aspin. Had to stop five times with excruciating cramp. Passed after about an hour and completed the ride.”
Photographer and cyclist Henry Iddon: “At the end of the points race (160 laps of the track) at the World Masters Track Champs in Manchester over 20 years ago, I got cramp in my right calf as we crossed the line at the finish. Back wheel momentarily locked while sprinting. Dunno how I held it up. I finished 10th. I still have a spot in my calf that knots up if I do a lot of exercise.”
Mike Broadbent: “I suffer with cramps, which I perhaps incorrectly link to caffeine intake. A cafe stop with a coffee means I’m in for a cramp session later. It seems to have a strong effect on me.”
And on it continued. All debilitating; all possessing the potential for comedic effect like this unfortunate recreational cyclist whose right calf seized up. Still, not quite at the level of former bodybuilder Paul Dillett, affectionately known as ‘Freakenstein’ because of his freakishly muscular physique, who froze on stage when unleashing a double bicep pose (no, we’re not 100% sure what that is, either). Four officials had to carry his 100kg-plus body off the stage. The severe bout of cramping resulted from dehydration caused by extreme use of diuretics. Not to be recommended.
So, we know what cramp is. And Johnson’s given us an inkling of its cause, namely depletion of energy. But that’s just one idea. That doesn’t explain why it’s common in the heat or why it can often come on at night. In fact, for such an everyday occurrence, cramp is a rather mysterious phenomenon. As Maughan stresses in his paper, “It seems likely that there are different types of cramp that are initiated by different mechanisms.” Which he elaborates on with the two main theories around cramping: electrolyte imbalance and “abnormal spinal reflex activity”.
“One of the greatest theories around cramping is the disturbance of hydration and electrolyte balance,” Maughan writes. “There’s evidence that individual athletes who lose huge amounts of salt in their sweat may be more prone to cramps.”
Riders will ensure they are hydrating correctly with water and electrolytes (Image by Getty Images)
It's certainly a theory close to Andy Blow’s heart. Blows a former world-class triathlete whose career stumbled into the wall because of cramping. “For as long as I can remember I had been especially susceptible to ‘sudden, involuntary, spasmodic contractions’ of my muscles to the point where cramps ruined numerous important races for me,” Blow explains. I was also plagued with horrible contractions in my legs that woke me up during the night after hard training sessions, and on one memorable occasion cramp even cost me a chicken tikka masala when an extremely violent hamstring spasm made me kick over my table during a quiet meal after a race.”
Blow’s wrestling with cramp resulted in him founding Precision Hydration in 2011, now Precision Fuel & Hydration, the sports-nutrition outfit specialising in understanding an athlete’s sodium needs and then prescribing a suitable sodium tablet: 500mg, 1,000mg or 1,500mg.
“The theory goes that a significant disturbance in fluid or electrolyte balance, usually due to a reduction in total body exchangeable sodium stores, causes a contraction of the interstitial fluid compartment around muscles and a misfiring of nerve impulses, leading to cramp,” Blow says. “In simpler terms, if you lose a lot of sodium and don’t replace it (as is common when you sweat a lot), it can cause fluid shifts in the body that in turn causes cramps.”
It's why cramp’s associated with hot weather – simply, you sweat more so lose more sodium – and it’s backed up by several studies including analysis of evidence of cramp among American footballers, which showed that the great majority (95%) occurred during periods of hot weather.
A 2019 study also showed that the severity of cramps was reduced when the athlete had taken sodium, while a 2021 study concluded that athletes who drank water containing electrolytes were less likely to develop muscle cramps after a workout.
Despite the work in the labs, arguably the strongest evidence of electrolyte’s role in cramping was found in large-scale observational and prospective studies of industrial workers – mainly studies on miners, ship’s stokers, construction workers and steel-mill workers that were conducted in the 1920s and 1930s – where saline drinks or salt tablets greatly reduced the incidence of cramps.
At the time, a chap by the name of Moss published an extensive report that attributed cramps to high air temperature, excessive drinking of water and continued hard work. He also noted it occurred more often during second half of a shift and in men who were less physically fit, so not just sweat losses “but also fatigue in the aetiology”.
That said, it should also be noted that cramp was not attributed to dehydration or increased serum electrolyte concentrations but rather “to a form of water poisoning of the muscles brought about by the combination of great less of chloride by sweating, excessive drinking of water and temporary paralysis of renal excretion”. In one further study, 12 cases of cramp required hospitalisation in one day.
Why the sodium uncertainty is arguably down to the difficulty of measuring cramp. Take a further study into road cycling that highlighted sodium levels in the blood plasma, which researchers were measuring, didn’t correspond to sodium levels at the muscular and neurological level. To achieve that analytical nirvana would require a muscle biopsy at the exact time an athlete cramps. In other words, it’s not going to happen.
Tadej Pogačar said he experienced cramp in both legs during Il Lombardia (Image by Getty Images)
Shot of magnesium
While Blow and his company focus heavily on sodium, he also recognises the potential role other electrolytes play in cramping. “Cramps are often present in lists of the classic signs and symptoms of many electrolyte deficiencies including low potassium or magnesium levels,” he says. “As both are lost in relatively tiny amounts in sweat, however, it’s unlikely that this is going to be a cause of cramping in athletes during endurance activities.”
Twitterer Jacek Kapela disagrees: “I always carry a magnesium shot of around 375mg. It works instantly. I remember when my training buddy suffered with leg cramps atop the second toughest climb in Slovakia and almost fell off his bike. It was 37°C in the shade, 50°C in the sun and he had severe dehydration. The magnesium helped.”
Johnson’s another who subscribes to magnesium, and potassium, supplementation. “You may not sweat out a huge amount of either but you also may not get enough in your diet,” he says. “I’d recommend a daily magnesium supplement of 400-500mg. But don’t take the citrate version as it can have a laxative effect.” Nasty.
The second major theory is that “abnormal spinal reflex activity” Maughan talks about; in other words, the ‘neuromuscular theory’. “This theory proposes that muscle overload and neuromuscular fatigue are the root causes of Exercise Associated Muscle Cramp (EMAC),” Blow explains. “The hypothesis is that fatigue contributes to an imbalance between excitatory impulses from muscle spindles and inhibitory impulses from Golgi tendon organs, and that this results in a localised muscle cramp.”
In other words, muscles tend to cramp specifically when they’re overworked and fatigued due to electrical misfiring. Arguably, this theory has a more solid weight of evidence behind it because it’s possible to assess. Back to Blow. “It’s much better suited to being tested in a lab, where researchers can ‘excite’ muscles with electrical stimuli and provoke muscle cramps to measure what is happening at an electrical level, and so there’s arguably more robust data to support it.”
It's why stretching is a pretty universally effective method to fix a cramp when it’s actually happening. It places the muscle under tension, invoking afferent activity from the Golgi Tendon Organs (part of the muscle responsible for telling it to relax) and causing the cramp to dissipate.
Like the electrolyte imbalance theory, it’s not a new idea, stretching back over 100 years. Telegraphists’ cramping, affecting the small muscles of the hand involved in the repetitive movement of those operating a Morse Code instrument, was the subject of a UK Parliament Enquiry that published its findings in 1911. The Committee wrote, “Some have regarded it as a muscular disorder; others a peripheral nervous system; others as a disease of the CNS… We accept it’s a weakening of the cerebral-controlling mechanism in consequence of strain upon a given set of muscles.”
It's why a recent study in the Journal of Strength and Conditioning Research suggested beating cramp lies in the gym. A team from Spain had 84 runners preparing for the Valencian Marathon undertook a battery of physiological and performance tests in an effort to differentiate between crampers and non-crampers.
Twenty subjects endured race-day cramp, equating to 24%, but there was no discernible difference between the two group’s hydration and electrolyte levels. What did differ to rather significant levels was creatine kinase and lactate dehydrogenase, both muscle-damage markers. Twenty-four hours after the event, the crampers registered 2,439 international units per litre compared to 1,167 in the cramp-free crew.
Analysis of training loads proved similar; in fact, just one exercise strand differed – 48% of the non-crampers undertook regular lower-bodyweight training compared to 25% in the crampers. The former had apparently bulletproofed their limbs for the endurance feat to come. The take-home? Undertaking leg exercises like squats and leg press a couple times a week with a load up to 80% of your maximum could result in cramp-free cycling.
Demi Vollering experienced cramp during the women's world championship road race (Image by SWPix.com)
So, electrolyte imbalance or neuromuscular fatigue it is. But that’s sidestepping further research by Professor Martin Schwellnus of the University of Pretoria, who stated that risk factors included older age, higher body mass index (BMI), shorter daily stretching time, irregular stretching habits and cramp in the family. More worryingly, he also identified common factors of EAMC included underlying chronic disease (including cardiovascular, respiratory…) as well as cancer and regular medication use.
What can be done? Well, we’re confident that a well-planned hydration strategy will help. The likes of Precision Fuel & Hydration conduct sweat tests around the country for bespoke sodium prescription. Alternatively, channels of white nestled on your cycle top’s a clear sign you’re a heavy sodium sweater. Magnesium and potassium supplementation will do you no harm, either.
And then there’s pickle juice , which garnered headlines several years back for its cramp-easing properties. If you can stomach it, there is evidence that it helps, though potentially not for what many thought – the electrolytes that are swimming within; instead, says The Cooper Institute, “The acetic acid in pickle juice is ‘noxious tasting’ and proposed to chemically stimulate a reflex in the back of the throat. This reflex has been shown to decrease activity in the alpha motor neurons, which causes muscle relaxation. You don’t even have to swallow the pickle juice to trigger the reflex, which can relieve cramps in less than four minutes. It is possible that other noxious tasting substances may also provide relief from exercise-associated muscle cramps.” In short, gagging one end could ease the other.
Then there’s stretching, gym work and ensuring that your training rides match that of your race rides and so ensure your muscle’s not shocked into spasm come your next sportive. There’s no quick fix to this for as Maughan concludes, “The search for a single strategy for prevention or treatment is unlikely to succeed.”