Considering cramp is one of the most common muscle issues to affect cyclists, very little is known about it. Ask five people what cramp actually is and you will get five different answers. Ask them what causes it and you might not get answers at all!
As far as we know, cramp is brought on by either muscle fatigue, dehydration, lack of minerals, injury or a medical condition. According to the NHS ‘Leg cramps are a common and usually harmless condition where the muscles in your leg suddenly become tight and painful.’
Cramp causes the muscle in question to shorten which causes the pain. The muscles are designed to do that very thing, but only in a controlled and predictable way. This involuntary shortening stresses the muscle and connective tissue, which generates the discomfort.
The current hypothesis is that some kind of change interrupts normal neuromuscular control which manages how, when and how far muscles move. Those contributors above can affect that neuromuscular control, which in turn, causes muscles to cramp.
Cramp from muscle fatigue
If we overwork a particular muscle, it tires. The build-up of lactic acid from exercise causes certain enzymes in the muscle to slow down. Those enzymes control the contraction and relaxation of muscles, which is where it is believed cramp comes from.
Cramp from dehydration
Water is heavily involved in just about every physiological function there is. It is also involved in the transportation of energy and nutrients to muscles as well as a contributor to nerve function. It is currently thought that water itself is essential to normal function but also transports essential minerals to muscles. The lack of either can result in cramps.
Cramp from lack of minerals
According to the Mayo Clinic, cramp can be brought on by electrolyte or mineral depletion. That’s not just salt, but potassium, calcium and magnesium. All of which are depleted during exercise. If not replenished in sufficient quantities between exercise, it can interrupt the normal contraction and relaxation of a muscle. Unfortunately, there is no specific reason why except the belief that these minerals help with neuromuscular control.
Cramp from injury
Any underlying injury can cause issues because of limited movement within the affected muscle. If the muscle in question is already compromised, it is very easy to push it too far or stretch it too much. The current theory is that injury works the same as muscle fatigue in that the enzymes that control the muscle do not work properly.
Cramp from a medical condition
Sufferers of diabetes, nerve, liver or thyroid conditions can also suffer cramp more than others.
Managing cramp when it hits can save a ride if you’re out and save discomfort whether you’re out on your bike or not. Mild cramp is usually treatable by slipping into a lower gear and pedalling higher cadence. This allows you to keep the muscle moving without the load.
If that doesn’t work, try shifting position on the seat, standing up for a bit or otherwise shifting the angle, intensity or effort on the muscle in question.
If the cramp is severe enough to force you off the bike, stop somewhere safe and walk around a bit. Don’t stretch the muscle out as this could make it worse. Keep the muscle moving, just in a different way and at a lower intensity. Take on water and electrolytes as much as you can while doing it. Once the cramp has eased, get back on the bike and ride at a lower intensity. After a while, build it up again slowly.
If cramp hits, you will need to assess what went wrong once you get home. Are you overtraining? Nursing an injury? Eating or drinking enough? Taking on electrolytes when you need them? Sleeping properly? Comfortable on the bike?
Wherever practical, it’s a good idea to build up to an event or to a distance so you don’t injure yourself. That means don’t hit those Cat2s until you have prepared for them or doing the century until you can comfortably do an 80 miler.
Cramp as a one off shouldn’t be an issue. It could be something completely random and out of your control. However, if cramp happens more than just once, you will need to look at your intake, position, condition and all those things above.