Muscle Cramps – most of us have had muscle cramps before, but why do we get muscle cramps and how do we stop muscle cramps from coming on during your run.

Many runners, especially long- distance runners have experienced the pain of muscle cramps. Approximately 30-50% of all marathon.

Even though Muscle cramps are quite common in runners the reasons why we get cramp still aren’t that clear. Some of the hypotheses are:

  1. Electrolyte depletion
  2. Dehydration
  3. Muscle fatigue and altered neuromuscular control

Most of us know the theory that being dehydrated and having burnt off electrolytes due to increased sweating from exercise can lead to muscle cramps.

It was the loss of magnesium & sodium that were thought to cause muscle cramp.

More recent research suggests that you can suffer from muscle cramps, even if you are hydrated and have good electrolyte levels -Which is why sometimes drinking sports drinks full of electrolytes or having salt or magnesium tablets may not always work.

Recent investigations have brought about theories around muscle fatigue and altered neuromuscular control. It is an extremely complicated process that involves the activity generated in the nerve fibres themselves.

When your muscle gets fatigued, the force it can generate is reduced and the amount of inhibitory input to your muscles via your nerves gets reduced as well, which leads to muscle cramp.

Cramp is more common in runners with less training and muscle conditioning and is also more common towards the end stages of a run or race.  The muscle is likely to have greater fatigue at this point. The faster you run, the quicker your muscles are likely to fatigue and the greater chance of getting muscle cramp.


Preventing muscle cramp

What can you do to prevent the onset of cramp?

Apart from staying hydrated with sufficient electrolyte levels –

Trying to reduce muscle fatigue by improving your muscle conditioning is going to assist in preventing cramp. Training by running more can condition your muscles for running, resistance exercise as well as strength and endurance gym exercises can all be part of your muscle cramp prevention strategy.

Your City Physiotherapy & Sports Injury Clinic Physio can work with you on specific endurance exercises for your main running muscles that often suffer fatigue and cramp – your calf and your hamstrings as well as your core and trunk control muscles. Adding speed to your running training sessions will also train your muscles at a higher intensity and build up resistance to muscle fatigue.  If you are leading up to running a race, making sure you taper your training right back in the 3-4 days before the race will ensure that your muscles aren’t already fatigued before you even start.


To book an appointment to help improve your running and improve your muscle endurance give City Physio a call on 08 8212 4886 or book online at