Thyroid UK
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T4 and regular exercise does it work?

I have been on Levothyroxine for five years approximately but my old symptoms seem to be coming back.Especially after regular gym exercise . Colds , sinus problems and feeling worn out. Its a stand in joke that it wont be long until i am ill again with my mates. My feeling is that it has something to do with my immune system breaking down, anyone else have this problem? Any ideas?

20 Replies


There are several things you could look into. Firstly I would recommend getting a thyroid test and getting your results and the reference ranges and post here. It might be that you need a higher dose of thyroxine even though your blood tests are "normal". Normal has a very wide range but each individual has a very narrow range at which they feel well. People on thyroxine need to aim for a TSH of less than one (in most cases) and a T4 at the top of the range in order to feel well.

Another thing to investigate is your iron levels. As well as making you feel tired anyway, low iron can cause problems with your cells using the thyroxine. You need to aim to have your serum iron well inside the range and your ferritin above 120 (I think that's right for men). It may be in the normal range but, again, normal isn't necessarily optimal and if your ferritin is lower you may benefit from an iron supplement taken with vitamin C and various B vitamins.

It would also be prudent to have your folate and vitamin B12 tested as deficiencies in those can cause similar symptoms and also have an effect on how our bodies produce and use thyroid hormones. Your folate should be well within range and your B12 above 400-500. This is well above the NHS bottom of the range but necessary. Countries like Japan have a minimum normal limit of around 400.

Another problem may be adrenal insufficiency, not like Addison's disease but a less permanent kind. It would be a good idea to look on the web about adrenal fatigue or insufficiency. Some names that are helpful when searching are Dr Rind and Dr Wilson. Have a look at the symptoms and see if any of them fit with what you are experiencing. You could pay for a saliva cortisol test that would tell you what is happening and you can find this on the main Thyroid UK website.

If you do have adrenal fatigue, where your cortisol levels are not right, this will affect conversion of thyroxine into the active hormone T3 and this will make you feel like you are not getting enough thyroid hormones and are hypothyroid again. This is very common in hypothyroid patients but is mainly treated with self-help measures which you can find on the web.

Vitamin D is another one worth looking into as deficiency is quite common in the UK. It could explain your symptoms as vitamin D is involved in over 300 metabolic processes.

I hope this helps to give you some ideas about what might be causing your return of symptoms.

Carolyn x


Wow! thankyou for a great answer, it is much appreciated.You obviously know a great deal about this, i must educate myself! This is my first time on a web site and it is great to see I am not the only one with these problems. You have given me a great heading to take, and I will try to get as many of these test done as possible. I will post when I have them. thanks again x


And another problem is that excercising uses up your hormones. So if you don't have enough to begin with, you are going to start feeling hypo again. You don't say how much levo you're taking and you don't say how much exercise 'regular' exercise is, but this could be the problem.


Hi thanks for coming back to me. I am taking 100mcg a day, and I was trying to train four times a week. Generally running for 30 mins at a steady pace, 30 mins of weights and maybe 10 mins of rowing each time.


That sounds like a lot of exercise on a rather low dose. Any chance of increasing your dose? Or reducing your exercise? After all, you wouldn't expect your car to do 100 miles if you only put in enough petrol for 50, would you.


I am going to get a Doctors appointment asap, to discuss maybe increasing the amount and having another test. Any idea what amount would be a "normal "increase?. There are several other tests that I am going to try as well. Cortisol saliva test, a full iron test and as many of the others that CarolynB suggested. Do you know if the local G.P. will do these or will I have to go private? I live in Brighton if any body knows a good local private specialist, or I will travel anywhere in the world to feel better! I stopped training for a couple of months now, because i have felt unwell. I am not a fitness fanatic by any means, but just try and keep the weight of which is increasingly difficult at 48yrs old. Thanx again for all your thoughts!!


Increases should be small, 25 mcg, and every six weeks until symptoms have gone. But try telling that to a GP!!! All they are interested in is the TSH, and if that falls anywhere within the so-called 'normal' range (which is anything but!), they are content with that and think they've done a very good job. Not! But we can always try.

As to whether a GP will do all those tests, that would appear to depend on the individual GP, and his mood that day, and what he had for breakfast, and if his ulcer is playing him up. Or something. There doesn't seem to be any hard and fast rules about that. Once again, we can always try.

If you are having trouble keeping the weight off I would put that down to your thyroid status rather than your age. After all, what is age? Apart from years, I mean. It is the slowing down or your hormone production. And, unfortunately, yours are slowling down faster than they should. So, definately try for the dose increase, I would say.

Hugs, Grey


Thanks again, I will hope he is in a good mood! lol!

The advice is really appreciated and since I have found this web site my mood has definitely improved! I thought I was going mad until yesterday. I will post any results I get asap. Its great to read all these questions and answers It is certainly helping me. All the best


That is a really good point! As I have felt better, I have increased how much I can do and then felt hypo again because I was doing more and needed to increase my dose. I have recently increased my dose again and feeling much better. I had forgotten about that. Thanks for pointing it out. A very important point!


Thankyou again Carolyn b.Please see reply to Grey Goose x


Paul - are you getting your TSH tested regularly?

In the UK it tends to be each year, but I've read every few months is actually better. My thyroid function continues to deteriorate (I wasn't expecting this a year ago when I was diagnosed hypo) so I need to have my dose of T4 raised every so often irrespective of training needs.

Ben Greenfield is my favourite fitness guru - recommends minimal training for maximum results! I like this thinking!

Hope you feel better soon.



Hi Liza, I get tested maybe once a year. I was tested approx. 6 months ago and was told everything was "normal". Bens training system sounds perfect for me ! I will check it out.

Thanks for replying.


As Greygoose mentioned, I think Dr. Mercola had an article that many athletes become hypothyroid. It may be a temporary problem when hormones are depleted. It may also be the reason many athletes take T3 which is the "active" hypothyroid hormone.


Hi, is this T3 synthesized or is this the natural desiccated thyroid I have started reading about. Sorry about my ignorance but I am just trying to learn about it all.

Thanks for reply.


Hi Paul, all T3 is synthetic except for the 20% found in Natural Desiccated Thyroid (NDT) which is T4/T3. You could peruse some of these links which explains a lot about hypothyroidism from this excellent website.

I don't think it's an immune problem but I have no credentials except for a lot of reading and research over the years. I think you use up your reserves when exercising. My muscles have shut down and I have collapsed on a golf course. I was undermedicated with my Armour and may also have low adrenal function which I am trying to sort out. But between too much heat and extra physical stress, my muscles just gave out. After a rest I was fine again, is that how it is with you?


Hi Heloise, thank you for the web site it looks very interesting.

I haven't been that bad as yet. I stopped going to the gym because it took me to long to recover muscle wise .It also seemed that when I undoubtedly got some cold would take weeks to shift it if not months. I have taken up golf again as well as I used to play a great deal about 15 years ago. It is strange you have mentioned this as when I played last week I found my legs were aching badly after a few holes and I was short of breath, just walking up some inclines. I was puffing like an old steam train! my partners noticed and asked if I was alright? I was very tired when I got in. It wasn't hot here , but being hot I can not stand any more. On holiday I stay under the shade now, where as I used to live in Florida for a while and loved the sunshine! I am going to look into Adrenal fatigue also, because some of the symptoms seem relevant to me. (NDT) sounds interesting as well , more reading needed!

thanks for replying , its appreciated.



You are welcome, paul. All the above sounds very familiar. Be sure to check other aspects including B-12, ferritin, folate, and vitamin D, also very important.


Thanks again.


Take Vitamin D3.. lots of it... that will help with the stamina... I find that if I take 5000 IU of vitamin D I can exercise a bit.. Your Transferrin saturation level may be too low.. your vitamin D may be too low (you need 80 to be fit fit) so you could try Iron and D3 (should get your tests first.. you don't want to be overdosing) . but generally... you've got a thyroid issue.. you're going to have to take it a bit easy, chap.. they're right.. get the tests done again.. and make sure they do the Vitamin D and Transferrin saturation.. if your D is lower than 80 and or your transferrin is less than 20, then getting those up will CERTAINLY help.. you probably do need more Thyroxine or even a mixture of T3 and T4.. but you will need to fight quite hard to get all of this.. Priority A is having a GP that will listen.. good luck with that


Thank you for the advice. I am speaking to the doctor today and I will try and arrange some tests which I will post asap. It does seem that from what I have read and the kind reply's I have received that as you say I may have a fight on my hands! But I have to start somewhere, thanks again Redditch.


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