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What causes cramp?

FiFi Posts: 31
I forgot to say - the cramp was in my foot in the pool and in my side whilst running up a hill so it's not an injury thing.



  • FiFi Posts: 31

    I was just wondering if anyone could tell me what causes cramp and how do you get rid of it or prevent it? I've had it whilst swimming (pushing off the wall) and when putting in an effort on a hill. In both instances I was very well warmed up so I know it's not that. I'd like to find out how to prevent it to stop it happening during my race.



  • MGMG Posts: 470
    Hi Fi,

    Its not known exactly why cramps develop. Insufficient stretching, not warming up enough and muscle fatigue all play their part. Imbalances in electrolytes (chloride, sodium, calcium etc) in the blood can also lead to cramping. Make sure your properly hydrated, and maybe try some form of electrolyte replacement drink S.I.S do one. Good luck!!
  • BritspinBritspin Posts: 1,655
    I heard a theory the other day that fits your calf cramp & possibly the side cramp too. Studies show no correlation between hydration &/or electrolyte balance as previously thought, currently the 'blame' is thought to lie with the stretch receptors in the muscles/tendons & ligaments.

    When you push off from the pool side, you lengthen the muscle at both ends, as the soleus muscle (deep calf) crosses both ankle & knee joints, causing the stretch receptors to do their job perhaps a little over enthusiastically to prevent the perceived threat of injury occurring, muscle then spasms & cramps. Similarly, when running the hips flex & extend, causing a stretch/relax action above the illiac crest & below the rib cage, upper body movements do the same, thus resulting in a two way stretch.

    Sounds reasonable, but no one can tell my why it only happens sometimes. No one has managed to replicate a cramp effectively in the lab, well not consistently. To study the mechanism properly one needs to be able to say when I do...this...then cramp always (or almost always) results, then the actual mechanism can be properly explored. Until then....we are all theorising & guessing. I seldom cramp, but Lady Britspin cramps much more easily, but she takes multiple asthma medications which have this as a listed side effect. Outside of that I know folk who seem to cramp very easily.
  • treefrogtreefrog Posts: 1,242
    Cramp is caused by electrolytic imbalance in the muscles. You probably don't wnt to know the full biochemistry, but basically your muscles move due to reactions between ions (charged particles). These ions are found in salts (not just table salt but also potassium salts, magnesium salts etc). If the correct type and amounts of ions (salts) are not in the muscle when the nerve fires it then cramp ensues. Cramp can be avoided by eating/drinking correct foods - Isotonic drinks pride themselves in this but the correct proportions of most foods can be just as good. Look at the ingredients of any sports drink and watch for PTE (periodic table of elements)
  • BopomofoBopomofo Posts: 980
    Two almost completely opposing views there from Britspin and the frog... I'm on the fence here, but anecdotally I can say that if I'm going to get cramp it's usually when I'm swimming, and if I do it is pushing off (calf, thigh) or putting my fins on (instep) that does it. I can also fairly well predict if I'm going to get a running cramp too.

    Brit and Frog: can you point us to the research docs etc that you have got this info from? I'm not questioning your integrity or anything... just happily prepared to plough through the full medical details to see if I can glean any info.

    When I get cramp the precursor is, usually, still feeling tired from an eariler hard session. Not a distance session, usually, but a harder speed, hill, sprint session etc. The cause seems to be hard and explosive muscle use: pushing off, kicking hard with fins on, sprinting up a hill.

    As to prevention.... I try to eat the right stuff, make sure I am properly fed well before my late tough sessions (i.e. swimming is 9-10pm, so eat a decent low G.I. meal by 7:30pm) and be aware that if I've already done 40 miles on the bike then pushing off the wall really hard is going to pee my legs off. If I'm still aching from the last session, then I am a candidate for cramp.

    If you are getting cramp don't try to run/swim/bike it off. Stretch it out and save it for another day.

    Another thing I've discovered: Once you are heading towards cramp, no amount of energy gel or other supplements will save you.

  • BritspinBritspin Posts: 1,655
    Hi Bop. There is a huge amount of info/argument (in the reasoned exchange of opinion sense), on scienceofsport.blog, beware of spending your whole day chasing threads & links. The stretch theory was a course I was on, I will try to get the presenters original reference & post it on here.

    I think it was on scienceofsport where there was an argument that the electrolyte balance thing does not work, otherwise it would be easy to create a cramp condition in the lab & let it happen, plus the drinks manuf would say that wouldn't they? They have gallons of sugar water to sell.
  • FiFi Posts: 31
    Gosh it's one of those subjects where there is no real answer. I asked a swimmer friend yesterday and they said to eat a banana 30 minutes before getting into the pool. I'm guessing potasium in the banana would help. I think 220 should do a something BIG on nutrition it's such a vital part of the sport. I'm a pretty healthy eater but I'm not sure if I'm fueling this new sport correctly. Perhaps I'm not eating enough potassium? i'm not sure about the stretching part as I'm always well warmed up. Perhaps someone needs to invent some new stretches!!!
  • FiFi Posts: 31
    Wow Britspin, you're a real boff! It's interesting reading your Sport Science theory. Thanks.

    In the mean time I've found a home made energy bar I'm going to try and make this weekend. I think it may help top me up in the nutirents department:

  • BritspinBritspin Posts: 1,655
    Nope, just a saddo who finds this stuff interesting, well that & its kinda my job too.
  • TommiTriTommiTri Posts: 879
    what do u do britspin? if you don't mind me asking!
  • treefrogtreefrog Posts: 1,242
    I don't have the exact references or journals to hand, (they are in attic) - I had a hand ina paper some time ago in which cramp featured and all the evidence pointed to electrolytic imbalance. I have been out of the cut and thrust of biochemistry for some time and have eneded up in teaching and quite readily admit that new cramp theories may have comr to the fore ..... but given the stuff I worked on 10 years & more ago I doubt it.
  • First timerFirst timer Posts: 139
    Ok reasons for cramp basically are due to The overflexing (Hyperflexion) of the muscles i.e overstreched, poor/lack oxygenation of blood through the muscles and low salt and or calcium in the blood.The body has a dellicate sodium/pottasium balance and go outside of that is when you experiance problems.

    So the importance of streching before you start is high so as to loosen the muscles and to increase your water and salt intake which is where your isotonics etc come in.

    I used to get cramp on the bike leg all the time but after increasing my fluids and a better stretch they are no more.

    Sorry hope it wasn't to technical tried to keep it simple my job tends to help alot with these things.

  • BritspinBritspin Posts: 1,655
    Gym manager/personal trainer/coach & interested bystander hoping to get an edge to make be better/faster.
  • BritspinBritspin Posts: 1,655
    A ha, here it is, the reference I was looking for...http://scienceofsport.blogspot.com/2007/11/muscle-cramps-part-1-theories-and.html
  • FiFi Posts: 31
    mmm. Out of all the responses mentioned I imagine it could be low salt intake. I'm not keen on salt - actually I detest the stuff and only eat fresh produce. I don't cook with salt either and drink lots of water to rehydrate. Perhaps I'm excluding it too much? I think the answer may be to have one of those sports drinks after a work out.

  • MGMG Posts: 470
  • BritspinBritspin Posts: 1,655
    Or not. Most people acquire enough sodium through their diet & have little need to supplement, until a few years ago sodium (or table salt) was only added for taste & flavour, now it has become an ergogenic aid. Most foods that have some processing contain salt..it holds water, plums up meats & give bland over produced pap a 'taste'. So altho over drinking can deplete sodium & your diet may be free from 'manufactured foods' as such you probably do get enough salt/sodium.
  • toadtoad Posts: 104
    sodium intake becomes really important in ultra distance , due to loss via sweat and excessive water intake.... hyponaturaemia ( I think i spelt that right ) in which the water sodium balance is altered leading to cerebral oedema ( swelling of the brain ) is an important factor to consider when doing ultra distance.

    I agree with Brit spins comment that sodium is probably less of an issue for normal triathlon due to its abundance in the diet. However if you are doing two long training sessions a day, still probably worth considering depending on your diet.

    My opinion cramps reflects alot of the previous posts, its likely there are a variety of causes hence no single cure. trial and error is probably the best management

  • FiFi Posts: 31
    Thanks BritSpin but I am wondering if it is salt because looking at my current average diet I can't see where it appears thinking about it. I've started having porridge for breakfast, lunch is usually cous cous with tomatoes, peppers and peas and my dinner which is usually potatoes, carrots, peas, beetroot leaves or spinach followed by rasberries and black currents are all home grown - I don't grow using any chemicals and I don't cook with salt. I buy my meat fresh from the local butcher and I don't think he adds salt to the products I buy off him - it's just as it ,comes fresh. Perhaps people didn't used to have this problem as they stored produce in salt? I think I'm going to try energy drinks.
  • BritspinBritspin Posts: 1,655
    In possession of sharp objects? Careful of that tongue Mr conehead.

    as for adding sodium..I am still not convinced, many foods have a natural sodium level within them, especially as you grow your own rather than intensively farm stuff, I am sure there are charts on tinternet giving approximate levels as a guide.
  • MGMG Posts: 470
    Some people sweat more salt than others, if this is the case you need to replenish those lost stores, sometimes you dont get all you need from food alone, you need to supplement it. If you take 100 different people not all of them will need the same nutrition, you tailor it your own specific needs, if you find that adding extra salt or elecrtolyte has the desired effect then you should introduce it to your diet.
  • FiFi Posts: 31
    Gordon Bennet! Why is cramp so complicated!!! I'm going to drink plenty of water, eat healthlily, train using a sports drink and strect well. I think that's all I can do really!
  • BritspinBritspin Posts: 1,655
    Research suggests that altho sweat rates vary, sodium lost thru sweat varies negligibly, & will be dictated by hydration levels & circulating sodium levels, so whilst there is no one size fits all solution, one can over drink, which is potentially more serious than de hydration, sports drinks seem to do little to mitigate & sodium supplementation is something of an old wives tale..check out the link to science of sport, theories yes, but worth takng on board & thinking about.
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