The Effect of Exercise of B12 levels? - Pernicious Anaemi...

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The Effect of Exercise of B12 levels?


Just a bit of advice really as I am coming to terms with a recent diagnosis of PA after a rough couple of months when the symptoms and my system said "enough".

I have had my course of 6 injections and I have to say, I feel much better now, with virtually all my symptoms going or gone.

However, I would like to start cycling again - nothing too mad, but I used to ride 2 or 3 times a week (for about 60-90mins max each time). I am wondering what this might do to my boosted B12 levels bearing in mind my next injection is scheduled for the middle of January 2019 - should I take it easy until the next blood test, and see where we go from there?

Anyone taken up a really active lifestyle following diagnosis and does that require more frequent injections?

4 Replies
clivealiveForum Support

Hi wiganer123 Personally I find P.A. is self limiting - if I overdo things one day it takes two or three to get back to "normal" (mine that is). However we are all different people.

I am not a medically trained person but I've had Pernicious Anaemia (a form of B12 deficiency) for more than 46 years.

I wish you well.

I’m a keen cyclist and I’m pleased to say that I’m as cycling fit as I’ve ever been, 3+ years post PA diagnosis.

My GP didn’t offer me loading doses but put me straight onto an injection every 2 months. At that point I was generally exhausted and had rides where I turned back for home and went back to bed at worst and was massively under par at best.

I had noticed that I was better for a short while after each injection and my GP agreed to let me have a monthly injection. This gave me a glimpse of my former self but my cycling was still up and down.

Over a year ago I decided to try weekly self injections and this has made all the difference. I live life on a fairly even keel, no more ups and downs.

I pay careful attention to my diet, making sure I eat well generally, with plenty of folate and potassium containing foods for example.

I’m on target for completing 5,000 miles on my bike this year, the most I’ve ever done in a year so I’m happy!

Your first target should be health, only once that feels in balance think about fitness. My advice would be to first and foremost listen to your body and don’t push through tiredness or any unwillingness. Build up gradually. Allow yourself to rest adequately between rides.

Also, find the right injection frequency for you, firstly for health, and once that’s established fine tune it as you add in more activity.

Good luck!

Exercise won’t make you use up B12 any faster than normal. But you’ve got to bear in mind that you are recovering from a serious illness. That means your energy levels aren’t going to be up where they were before.

The key is to listen to your body and to accept that if you overdo things then it may take you longer than it used to for you to recover.

I had a fairly active week for me, culminating in a walk with a few hundred thousand chums round London. I’m feeling good now, but I needed a full day of doing not much on Monday. Tomorrow I’ll be back on the normal exercise routine, but backed off a little. I know from experience that I’d have had the same if I’d been injecting more frequently.

I don't know if exercise uses up B12, or as fbirder says, it is simply that your body is run down but i must feels like it does. And given that B12 is required for cell formation, there is always micro-damage to muscles which have to be repaired so some of your B12 reserves have to be used but I don't know how much.

I'm a competitive badminton player and keen runner. When I was first diagnosed and received my loading doses, I felt wonderful and found myself able to train harder and run faster than I had done for ages and was able to knock about 30 seconds off my 5k PB. That carried on for about a year after which, I realise with hindsight, my stamina started dropping off and my legs would start filling with lactic acid. I noticed that my times would drop off as the next injection became due. I would get my three monthly injection and my times would pick up again as I was able to train more.

Unfortunately I left if for a couple of years, trying to work out if my deteriorating health was down to a virus or something else as my doctor assured me it couldn't possibly be B12. My legs would constantly feel as if I had had a really hard training session the day before and then I would think about it and realise that I hadn't done anything at all taxing for two or three days and my legs should feel fine. I did eventually try supplementing with a B12 spray and this helped. I could run faster (or less slow) and was able to train more but as soon as started to feel better, I would think I'd turned a corner and would enthusiastically throw myself into training only for my symptoms to come back with a vengeance and knock me back for a couple of weeks.

Now I'm self injecting weekly. I'm still running and competing but unfortunately I'm quite a bit slower (my times are 20% slower than they were four years ago). I'm improving but find I have to do it very gradually.

Sorry for this monster reply but it was a question that I was asking all the time. I was always a fit person who loved sports and would run players 10 years younger than myself around the court until they tired. If injured, as soon as I was able I would throw myself into training and within a couple of weeks would often be back close to pre-injury fitness. Now I find that if I'm out for a while I have to build up really gradually and it seems to take an age to get back to where I was before the injury.

I would say, do keep cycling and try to keep your fitness up but also keep listening to your body and if you find your symptoms deteriorate after exercise, it may be that you are either overdoing it or your need more regular injections.

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