Pale and dizzy during/after running

Hi all,

I was just wondering if anyone has experienced this?  On three occasions now I've either collapsed, or nearly collapsed when running. This all started in November last year.  Once was at the end of a half-marathon. in full flight heading towards the finish line - this was pretty much full collapse.  I was running as hard as I could at the time - luckily someone caught me before I hit the ground.  

Once it's happened at the end of a 10k race, just when I'd stopped - again, I'd been giving it my all and just when I crossed the finish line I couldn't stand up, was really dizzy and the steward told me I was really pale (I'm normally bright red when I run!).  I recovered within a few minutes.

 The other time was in the middle of a marathon - I'd been feeling sick and a bit dizzy from about half way and again became really pale and very dizzy about mile 15.  I had had plenty of water during the marathon and I run with a Camelbak with electrolyte solution so I don't think it was dehydration.  I had to stop for a while, then recovered enough to walk/jog on until the end.

I'm becoming a bit wary of really going for it in a race in case I do end up fainting and hurting myself.  I had blood tests done in December which showed I had low iron but this has been corrected and the latter two episodes have happened since then.  I know I'm not diabetic.

Do you think I'm just running beyond my ability?  I'm not a fast runner by any means - the half marathon I nearly killed myself doing was going to be just under 2h.  Is it possible just to push too hard?

I know I should probably see a doctor but if this is a fairly common thing I won't waste their time.

Thanks in advance image



    Only speculation but perhaps you are not far away from a cardiac arrest. Go and see a doctor asap, it could save your life.

  • No, this isn't common at all.


    You need to see a Doctor ASAP. That's not to say there's definitely something seriously wrong, but you need a good looking over.


    Stay well.

  • They're both fairly definitive answers! Will phone the doc today!

    Thanks image
  • Have you used a heart rate monitor while running?  Could be that your heart rate is alarmingly high. Even healthy and fit athletes can have heart problems which only kick in when you really push yourself (think Fabrice Mwamba).  Get yourself to the doctor's and don't get fobbed off - you need to get this checked out asap!

  • Joe VolcanoJoe Volcano ✭✭✭

    Even if you've already spoken to your GP, go back and insist on some proper cardiology testing. Irrespective of your age and fitness. Don't take no for an answer. I had several races with similar symptoms and thought it was just low blood pressure then I had a cardiac arrest. Good luck.

  • Joe Volcano, that's terrifying. I hope you're doing okay now. Will definitely insist on full testing after reading that.

    Thanks so much everyone. It's good to know I'm not just being a wimp.
  • I was interested to see this thread as it sounds very familiar, I ran my first race for 7 years on Sunday, the Hastings 5. I started running a short while ago with no problems at all other than aching joints etc. I ran the race in a very slightly higher pace than I have been running, right at the end my energy level plummeted to zero & as I crossed the line I was falling over with no control over my legs, luckily a guy grabbed my arm. I was extremely dizzy & sat down for a good 10 minutes, my legs were shaking as were my hands & it was half an hour before I could walk sufficiently to go for a drink. I felt light headed all day then had a banging headache in the evening. Next day I was fine, the day after I ran 6 miles with my club, completely ok. I am seeing the doc later today as it was not nice & I need peace of mind, I'll let you know what I hear.

  • Hi Andy, glad you're feeling okay now. I've seen the doctor and it turns out I have a heart murmur so off to the cardiologist next week for some tests.

    Ran a 10k last night, took it nice and easy and felt great image
  • I hope it all works out ok for you RR. I saw my doc who was 100% certain that it was a low sugar episode. I'd been laying off tha carbs after I started running again to shift some weight, she said that was the problem. Nice to hear nothing serious & I'll return to carbo loading! I was concerned at the time though as it was very unusual & I felt awful!

    I have a close family history of BD, Heart disease & also Diabetes so I am tested every six months, one test was last month & everything is completely fine so she's convinced all is ok & doesn't expect a reoccurrence, I was glad to hear it!

    All the best!

  • Best to see a specalist but I know someone who had this and it was low iron. When you run you lower your iron stores (each step kills red blood cells), if your iron is low already or you are mentruating then it is not unusual to have the symptoms of anaemia after a race. Try iron suplememts but see a doc or pharmasist before taking high fe (iron) supplements. But please see a specialist first to rule out cardio problems image

  • Just for anyone who may pick up this thread in the future, I thought I should let you know the outcome!

    I had a full investigation - echo, treadmill stress test, ECG and apparently there's nothing at all wrong with me.  I'm absolutely fine! 

    So, still no idea why I've keeled over on those occasions but at least I know my heart is in good shape.  I've been taking it easy with my running the past few weeks but I'll step it up again and see how I go.

    Fingers crossed it won't happen again!

  • Had something similar myself a few months ago.  Just felt dizzy towards the end of speed-work sessions, usually during rest intervals.  My dad was diabetic, so you can imagine that I was putting two and two together.  The doctor took my pulse rate and blood pressure.  Blood pressure was normal.  Was told I had an "athlete's pulse", (slow and steady) - result!  Just need an athlete's body now, or at least the lungs and legs!  Anyhow, had a blood test and no problem.  The doctor diagnosed it as labyrinthitis which is an inner-ear problem and said that it could be exacerbated by dehydration, so I always take a water bottle with me for interval sessions now.

    Hope you're ok now.

  • Glad to hear you got the ok too RR, my doc's certain it won't happen again so all I need now is for other injuries to clear off & I'll be ok!

Sign In or Register to comment.