Muscle Cramps: part two


You can almost taste the finish line. The crowd is getting dense, cowbells are clanging, and hands clamp faster and faster. You stagger and grimace as your left calf clenches, but it releases as you toe off. You’re right isn’t so luck and you hit the ground. Your hands immediately find your calf and squeeze trying to get the cramp to release.

As if the last post wasn’t bad enough, let’s further complicate this question of why do muscles cramp during exercise, specifically endurance running? Many times muscle cramps occur in the later part of an event. If this is the case, then the cause is likely muscle fatigue rather than dehydration, carbohydrate depletion, or electrolyte imbalances.

You have all read my posts (at least I hope you have, but if not go back and read some) about how important core strength is in preventing injury through compensation and recruiting supporting muscles. Here is just another reason for me to stress how important it is to strengthen your core increasing the time you can maintain proper form as you run.

Your core doesn’t just mean your abdominals. It includes your hips, glutes, back, and abdominals. Basically, from mid-thigh to the top of your abdominals all the way around your body. If these muscles are not strong, your form deteriorates as the primary muscles become fatigued. The contractions become more forceful to maintain your pace and your body can’t sustain it. You slouch, shuffle, and increase cross over of both arms and feet. When this happens, your body automatically asks other supportive muscles for help to keep you going. These supportive muscles fatigue at a faster rate because they are not used to the strain and then they cramp.

What can you do about it? If you are cramping in your claves and quads (usual suspects) you need to strengthen your hip flexors and hamstrings and then stretch them. When your hip flexors and hamstrings fatigue, they call upon the calves and quads to move your leg back and forth.

The take away, your body is an interconnected system. If you let one part get weak, the other parts will try to help it to their own detriment. This eventually leads to muscle impairment or injury and thus stops you in your tracks.

In case this isn’t confusing enough, there are researchers who believe running hills, inadequate stretching, and a family history of cramping increases the possibility of cramps.

This makes sense to me. Hill running forces your muscles to contract forcefully to propel your body up a hill against gravity. This strain is going to deplete glycogen (see last week’s post) and fatigue (see above) the muscles. Tight muscles have a more difficult time relaxing and at times just can’t do it because they are all knotted up. If they can’t relax between contractions, the contractions just continue to tighten things up and bam, a cramp. And genetics, well their genetics.

Muscle Cramps: part one


You’re cruzing along a trail feeling great and all of a sudden you fall to your knee clutching at your quadricep  as it spasms in pain. Muscle cramps are not new to athletes, including endurance runners. What causes it and how can you fix it during an event?

Muscles cramp for a variety of reasons, and usually a combination of them. Novice athletes are more likely to cramp than experienced athletes. Novice athletes pushing their bodies beyond their limits these fatigues muscles seize up as they are continually pushed.

Heat is a major culprit in muscle cramps especially for athletes who do not train in the heat. Their bodies are not accustom to dealing with scorching temperatures while making sure muscles continue to fire. Imbalances in electrolyte’s, dehydration, and depleted carbohydrates also create a higher chance of cramps.

Unfortunately, these factors hit an athlete all at the same time more often than not. Dehydration increases the risk of cramps, but it’s not a guarantee you will cramp. When you are hydrated there is a balance in the amount of fluid inside and outside of your cells. If you are dehydrated, there is less fluid outside of your cells. This situation causes nerves to be squished and fire which then causes twitches and then cramps in muscles. So just drink more water right? Sorry it’s not that simple.

Electrolytes make the cell walls permeable allowing the fluid to move in and out of a cell. If this can’t happen, an imbalance of fluid inside and outside the cell occurs and you have the same situation as above.

To further complicate the matter, insufficient carbohydrates leads to cramping as well. We all know muscles need glycogen to function and there is only a finite amount held in our muscles. When that is depleted we have to consume more carbohydrates. Glycogen is the fuel our muscles use to contract and relax. If our muscles can’t relax, they cramp.

What can you do about it? make sure you are drinking to thirst, taking electrolytes on a regular basis, especially in the heat, and train for the conditions you will be running in.

Sodium and Chloride(aids nerves in firing and permeability of cells) are not the only two electrolytes although they get all the attention. Here are the others and what they do:

  • Calcium – aids muscle contraction
  • Magnesium – aids healthy cell function
  • Potassium – helps regulate pH balance
  • Phosphate – helps regulate pH balance


Choose electrolyte replacements containing all of these. If you want a good explanation of how each electrolyte works read this.