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How do I prevent muscle cramping during MTB races?

Athlete Question: I cramped up badly racing Park City Point 2 Point? What can I do next time to prevent that happening?

Coach Lynda: When athletes cramp in a mountain bike race it is most often the large working muscles in the legs that go first. Cramping is a painful experience and always slows you down.

So what causes muscle cramping? Umm…I don’t exactly know! The scientific community does not have a definitive answer, either! There are theories on what causes cramping but no certainties. The best we can do as athletes is to review all the cramping theories, compare them to our own personal cramping history and cover the preventative scenario we think applies to us in our training and race day plans.
The current cramping theories include fatigue, low electrolytes (sodium, chloride, potassium, calcium, magnesium), hyper-hydration, dehydration and personal susceptibility.

Recently a new neuromuscular theory has emerged that cramps are caused by an excessive firing of motor neurons in the spinal cord, not by the muscle. Under normal circumstances, motor neurons control muscle contractions without incident. But when the nerves are destabilized, painful cramps can occur.

After pulling out of a 24 hour race 7 hrs in.


Muscular fatigue is currently touted as the most likely cause of cramping. Pushing your muscles in a different way from how they have been trained by using a different movement pattern can cause cramping. Pushing harder, longer and faster than before can cause cramping. For mountain bike racers during the 78-mile Park City Point-2-Point, harder and longer is the most likely cramping culprit.


There are two ways to prevent cramping from fatigue; pacing and training. Pace your race to accurately reflect the level at which you have trained. Out-pacing your training is an almost certain recipe for cramping. Hold back in the first half of your race to prevent cramping. In training, push harder and longer to adapt to the pace you want to maintain during the race. This is a tough one to accomplish for a 78-mile mountain bike race that takes on average 9+ hours to complete – like Park City Point-2-Point.

There is anecdotal evidence that muscle cramping can be prevented by strength training. Perennial pro-racer and multi-time Leadville 100 winner, Dave Wiens wrote the following in his Road to Leadville Blog

I lift to, hopefully, prevent cramping. So far, this has helped me at Leadville. I have lifted going into this race the last three years and I haven’t cramped. In years when I didn’t lift, I’d cramp coming down Columbine, but I’d just kept spinning my legs, though, and they’d go away. It certainly isn’t doing my legs any good, though. I experienced the same thing in the Firecracker 50 this year – and in others – when I haven’t been lifting. I’ll try to get into the gym 8 or 9 times before Leadville, my last one being on the Monday or Tuesday before the race.


Muscle cramping may be brought on by loss of sodium, chloride, calcium, potassium or magnesium in sweat during exercise. This is the oldest cramping theory and recent evidence suggests it also the most unlikely cause of muscle cramping. However, as athletes it is also an easy one to cheaply and safely cover during a race.


Before the race add extra salt to your meals to top-up electrolyte supplies. Avoid over-drinking fluids the day before the race as that will dilute your blood electrolyte concentration. During the race supplement with a solution such as Elete or capsules such as Endurolytes to replace electrolytes lost in sweat.


Hyper-hydration is linked to the low electrolyte theory as drinking too much will dilute the electrolyte concentration in the blood.


Drink just the right amount and not too much to maintain electrolyte balance.


Dehydration may or may not cause muscle cramps. Avoiding dehydration is a no-brainer for racers, as dehydration negatively affects race performance in multiple ways.


Drink just the right amount and not too much to maintain hydration status.


Some people are simply crampers, while others are not. If you have read this far, then you probably are a cramper. There is evidence that cramping susceptibility increases with age.


Regular stretching, high intensity training and strength training may help reduce the incidence of cramping.


This theory is based on the premise that your muscles cramp when motor neurons in your spinal cord start firing off spontaneously and repetitively. Stimulation of Transient Receptor Potential (TRP) channels in the mouth activate a neural pathway that radiates from the mouth to the brain, with additional neural signals sent down the spinal cord that return the hyperactive motor nerves to normal function. Tastes like pickle juice, hot mustard and hot peppers stimulate these TRP channels. HotShot is a commercial product based on this theory.


Drink HotShot, pickle juice, hot mustard or eat hot peppers 15-30 mins before racing and then again during the race if cramps appear.

Once your legs do cramp in a race, your best option is to drop the pedal force and spin your way through them. If your cramps are too intense to keep the pedals moving, gently stretch the affected muscle.

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