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Dizzy and light headed

markwb79markwb79 Posts: 928
I have had a dizzy and light headed feeling a few times now.

I did my weekly long ride (5 hours) yesterday, it was hard at times, but never over stressed. I ate and drank regularly (large bowl of muesli for breakfast) I thought). two energy bars, and a gel (was trying them out) and about 1ltr of energy drink. After the ride we all stopped for a coffee, then on the roll back towards home, after 10mins I felt light headed and sort of dizzy.

I have had this a couple of times after some short circuit racing, finish the race, hang aorund for 10mins and have a chat etc. then ride home, after 10mins I get the light headed feeling.

On the ride yesterday I was never outside of my comfort zone. It wasnt warm, so didnt sweat much.

Any thoughts would be great.

Thanks
Mark
Scott Addict 2011
Giant TCR 2012

Posts

  • I take it this isn't normal for you, i.e. only happened the last few rides?

    From what you've said it doesn't sound like a training issue so it's worth speaking to a doctor.

    I know someone who is ridiculously skinny (so has censored all blood sugar) and would occasionally fall off of his bike sideways and momentarily faint at the top of a steep climb. That was simply training based though and lack of eating so it seems this does not apply to you from what you've told us.

    My best advice would to speak to your doctor.
  • markwb79markwb79 Posts: 928
    f**k, now you have worried me!

    Randomly, it only happens at the weekends! I ride every day, either commuting, or training (recently mostly in and around my threshold). Its just strange that its after I stop, have a chat, and then roll back home!

    I dont think I am super skinny, or skinny for that matter, but I have been loosing fat over the last couple of months.
    Scott Addict 2011
    Giant TCR 2012
  • mentalalexmentalalex Posts: 266
    this has happened to me before, when i've over trained, i was so dizzy, i could only lie down,

    was bed bound for two days,

    it can be a variety of things, but you said you only drank 1 liter over your 5 hour ride?

    it's more than likely dehydration, use 750ml bottles, fill up when you can on your rides,
    and when you get back, drink lots of fluid,

    try that

    hope thats of some use
    I do science, sometimes.
  • markwb79markwb79 Posts: 928
    yeah I was using two 750ml bottles, and had some left. So guessed at 1ltr, when I typed it I thought it wasnt that much!

    I am tapering this week for the Marmotte, so training will be less.
    Scott Addict 2011
    Giant TCR 2012
  • MountainMonsterMountainMonster Posts: 7,423
    Sounds like a definite water shortage to me. I drink on average about 750ml of water per hour, but I am constantly on the liquids even when not exercising. Remember, more hydration is better than less. The worst that will happen if you drink too much is the need to pee more often, much more acceptable side effect than passing out, if you ask me!
  • On re-reading your post, yes, the others could be right. The test that will tell you if it's dehydration or not is to go for a pee after riding and if the contents of the bowl isn't almost clear, you know you've not been drinking enough. It definitely shouldn't be the colour of something you would cough up if you were having a bad cold!

    It's worth experimenting on the next couple of rides and forcing yourself to drink more than you normally would. I know it feels weird but you need to train yourself to drink more on the bike. As a very rough rule of thumb, by the time you feel thirsty, it's already too late and you're dehydrated.

    The colour of the toilet bowl will reveal all!
  • doyler78doyler78 Posts: 1,951
    Sounds like a definite water shortage to me. I drink on average about 750ml of water per hour, but I am constantly on the liquids even when not exercising. Remember, more hydration is better than less. The worst that will happen if you drink too much is the need to pee more often, much more acceptable side effect than passing out, if you ask me!

    Actually overhydration can lead to death and the chances of that happening with endurance athletes is actually increased. Why? Because endurance athletes will sweat out essential electrolytes and overhydration only makes a bad situation worse as that further dilutes the concentration of electroyltes potentially pushing to dangerous levels.
  • mentalalexmentalalex Posts: 266
    doyler78 wrote:
    Sounds like a definite water shortage to me. I drink on average about 750ml of water per hour, but I am constantly on the liquids even when not exercising. Remember, more hydration is better than less. The worst that will happen if you drink too much is the need to pee more often, much more acceptable side effect than passing out, if you ask me!

    Actually overhydration can lead to death and the chances of that happening with endurance athletes is actually increased. Why? Because endurance athletes will sweat out essential electrolytes and overhydration only makes a bad situation worse as that further dilutes the concentration of electroyltes potentially pushing to dangerous levels.

    Then have a drink with those essential electrolytes to make a bad situation better...?

    if you ride for 5 hours and drink 1L that is not enough..... how many bottles do you reckon a pro peloton will for a 4-5 hour stage? 1L worth....erm no, they will get through a fair amount.
    I do science, sometimes.
  • doyler78doyler78 Posts: 1,951
    mentalalex wrote:
    doyler78 wrote:
    Sounds like a definite water shortage to me. I drink on average about 750ml of water per hour, but I am constantly on the liquids even when not exercising. Remember, more hydration is better than less. The worst that will happen if you drink too much is the need to pee more often, much more acceptable side effect than passing out, if you ask me!

    Actually overhydration can lead to death and the chances of that happening with endurance athletes is actually increased. Why? Because endurance athletes will sweat out essential electrolytes and overhydration only makes a bad situation worse as that further dilutes the concentration of electroyltes potentially pushing to dangerous levels.

    Then have a drink with those essential electrolytes to make a bad situation better...?

    if you ride for 5 hours and drink 1L that is not enough..... how many bottles do you reckon a pro peloton will for a 4-5 hour stage? 1L worth....erm no, they will get through a fair amount.

    I didn't say don't drink. I was challenging the poster above, whom I quoted, who said you can drink as much as you like and the worst that will happen will be that you will pee it out :wink:
  • mentalalexmentalalex Posts: 266
    :D
    I do science, sometimes.
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