athlete with a calf cramp


Until you’ve had a bad muscle cramp, you don’t really know you’re alive!  The pain can be excruciating!!!  If you have experienced cramps, and you want to minimize your risk of getting them, or reduce their frequency, or wonder if they mean something more serious is going on – here’s some info that you might find useful…

What is it?

A cramp is an involuntary extreme muscle contraction.  What an exercise physiologist might call a tetanic contraction.  That is, a full-on, all-out, could-not-contract-any harder contraction – that just won’t let go!  Seriously painful, muscle cramps most often occur in the calf but can happen in any muscle.  They can render you unable to use that muscle for a period.  They can involve twitching in the muscle (called fasciculation), which can feel and look weird!

Cramps may happen for no specific reason, although a collection of factors can probably be identified and managed in order to avoid this awful sensation.

Exercise-associated muscle cramp (EAMC) is a type of cramp that occurs during or soon after exercising and is usually associated with intense exercise (competition more than training), prolonged exercise (distance running, swimming or paddling = sweat+++) and exercising in hot and humid environments.

What causes cramps?

A whole bunch of things, so let’s bullet-point them:

  • Dehydration – likely to be the main reason for cramping, sweating causes us to lose electrolytes, particularly Sodium, Calcium, Potassium and Magnesium (Na+, Ca+, K+, Mg+). These are important chemical components with an electrical charge, which our bodies need to help regulate all sorts of processes, including nerve function and contraction and relaxation of muscles.  You could almost think of the dysfunction of cramping as being like a kitchen appliance you can’t switch off!  Imagine a beater or a blender stuck on “11”, and you can’t switch it off!
  • Fatigueneuromuscular control requires nerves to keep firing, but with fatigue they can start to fail, which may result in cramping
  • Spinal or nervous system pathology – damage to nerves, associated with trauma or degeneration or disease; some people who have had severe or prolonged sciatic pain may have difficulty with cramps on an ongoing basis
  • Vascular insufficiency – some people with diabetes or atherosclerosis (clogging up of the arteries) may experience a cramp-like sensation after walking for a while, which eases after a period of rest. This is called intermittent claudication.
  • Some medications – I’ll leave that to the doctors and chemists
  • Supplementsparticularly Creatine Monohydrate: this popular and generally safe supplement has proven to aid muscle recovery, muscle bulk and performance in terms of explosive or power-related sports. BUT if you take more than the prescribed dose you can absolutely expect to get cramps.  (Interestingly, these cramps often occur in hands and feet as well as the usual calves and hammies.)
  • Sustained shortening or over-extending of a muscle

Fatigue and dehydration are the main ones we need to think about in sporting contexts.

What to do when you get a cramp

athlete with a cramp

Stretch.  It.  Out.  This is pretty common knowledge, and almost intuitive, one would imagine.  For calves, pull the toes back toward the shins or do the classic calf stretch leaning into a wall.  For hamstrings, straighten the knee and tip forwards at the hips, or lift the straight leg up while lying on your back.

Moderate massage will probably help, as may heat if this is away from competition.

Try not to push through a cramp, or to load the muscle heavily immediately after, as you may cause soft tissue damage that could linger for some days.

What can we do to reduce incidence of cramps?  

Seeing as the context of this article is Sports and Fitness-related, let’s focus mainly on the active and environmental stuff, and leave the neuropathology and medication-related causes for another time.

  • Ensure you are remaining well hydrated, and maintain electrolyte balance
    • Drink plenty of water, especially if training or competing in heat and humidity
    • Consider an electrolyte supplement (‘sports drink’) if you are sweating a lot
    • Avoid alcohol, or if you’ve had a few drinks the day before, make sure you have had some extra water to drink
    • If you have been unwell – maybe had ‘the runs’ – make sure you get well nourished and hydrated to replace electrolytes lost as your body flushed itself out.
  • Mobilise your soft tissue and tap into reperfusion (“garbage out, groceries in”)
  • Eat a well-balanced diet – electrolytes don’t just come in sports drinks!
  • bananas are famous for potassium content
  • …but sweet potato has x6 more as well as calcium and magnesium
  • …and avocados have double the potassium of sweet potatoes!
  • Dark, leafy veges like kale, broccholi, spinach
  • Nuts and Seeds
  • …and, of course, Milk!
  • Consider supplements – magnesium is particularly popular and apparently effective in reducing cramps – but aim for real food first! (And go easy on the Creatine!)

(For more information on minerals and electrolytes in food, check out this link)


Darren Stuchbery is a Physio and Exercise Physiologist and Director of 6S PHYSIO in Mingara, Ettalong and Umina.  He is a cramper from way back (did he mention cramping is also age-related?) and has experienced ‘the claw’ from too much creatine monohydrate, as well as experiencing the joy of a hip flexor cramp while trying to deal with a hamstring cramp; but he says nothing compares to calf cramp while driving on the M1.  For advice on how NOT to experience any of the above, check in at 6S PHYSIO, the experts in cramps and other stuff.