As a cramper myself, when I do anything that last longer then 1.5 hours, it's always in the back of my mind. I've cramped since I was a young kid. Calfs mostly. Biking has brought on quad cramps and calf cramps.
I always tell people that science doesn't know why we cramp. It's pretty amazing. Seems like a simple problem. I'm always amazed when there is something in the body that we don't understand. It seems the more we study the body, the more we realize we don't know. Even a simple question like how does a muscle contract is under debate!
When it comes to cramps, we have theories and ideas. Some studies show a no, while others show a maybe. Here are a few.
1. Central Nervous System. Spinal Motor Neuron Hyper excitability. This is the Neuromuscular Imbalance theory.
2. Peripheral Nerve. Spasmodic discharge. Dehydration/Electrolyte theory.
Repetitive Muscle Exercise. Leads to muscle fatigue. Increase in excitatory afferent. Decrease in inhibitory afferent. Hyper excitation and discharge of alpha motor neurons.
Both Theories stimulation of spinal nerve afferent produce muscle cramps by spontaneous peripheral nerve activity. They have used a peripheral nerve block and essentially blocked cramps. So essentially the spinal loop must be intact for the cramps to occur.
It's been shown that dehydration/electrolyte doesn't avoid the cramps, but it does delay them.
A new player in the cramp genesis is called the Central Fatigue Mechanism. Studies are suggesting that brain stem or higher centers influences muscle activities. The evidence to support this theory is all indirect.
1. Ingest a CHO/electrolyte drink to help delay the.
2. Work on the tissue quality of the muscle that cramps. If you cramp in calf's, routinely get tissue work done on this muscle. Pain can induce cramps.
3. Learn pacing. If you are in a race. Athletes that did the first 1/2 significantly faster were more prone to cramping at the end of the race.
4. Get better technique. Avoids unnecessary muscular strain.
5. Try to keep the core temperature from rising. This goes into the central governing theory. You don't want your brain to shut you down.
6. Keep muscular glycogen high. This allows the brain to think you are doing fine.
Here is the video from these notes.