Impact of overt and subclinical hypothyroidism on exercise tolerance: a systematic review

[helvella]

Having recently read here lots of posts mentioning, in various forms, degrees of exercise intolerance, I happened upon this paper. Quite astonishingly it uses terms like "quality of life" and "forgotten area", and it absolutely recognises different systems working in concert to produce the effects suffered by so many.

(All too often everything to do with sports and medicine seems to concentrate on elite athletes. Really good to see something for the rest of us.)

Res Q Exerc Sport. 2014 Sep;85(3):365-89. doi: 10.1080/02701367.2014.930405.

Impact of overt and subclinical hypothyroidism on exercise tolerance: a systematic review.

Lankhaar JA1, de Vries WR, Jansen JA, Zelissen PM, Backx FJ.

Author information

1a University Medical Center Utrecht .

Abstract

PURPOSE:

This systematic review describes the state of the art of the impact of hypothyroidism on exercise tolerance and physical performance capacity in untreated and treated patients with hypothyroidism.

METHOD:

A systematic computer-aided search was conducted using biomedical databases. Relevant studies in English, German, and Dutch, published from the earliest date of each database up to December 2012,

were identified.

RESULTS:

Out of 116 studies, a total of 38 studies with 1,379 patients fulfilled the inclusion criteria. These studies emphasize the multifactorial causes of exercise intolerance in untreated patients by the impact of limitations in different functional systems, with cardiovascular, cardiopulmonary, musculoskeletal, neuromuscular, and cellular metabolic systems acting in concert. Moreover, the studies affirm that exercise intolerance in patients is not always reversible during adequate hormone replacement therapy. As a consequence, despite a defined euthyroid status, there remains a significant group of treated patients with persistent complaints related to exercise intolerance who are suffering from limitations in daily and sport activities, as well as an impaired quality of life. An explanation for this phenomenon is lacking. Only 2 studies investigated the effects of a physical training program, and they showed inconsistent effects on the performance capacity in untreated patients with subclinical hypothyroidism.

CONCLUSIONS:

A limited body of knowledge exists concerning exercise tolerance in treated patients with hypothyroidism, and there is an insufficient amount of quantitative studies on the effects of a physical training program. To enhance exercise and sports participation for this specific group, more research in this forgotten area is warranted.

KEYWORDS:

physical activity; physical performance capacity; quality of life; thyroid dysfunction

PMID: 25141089 [PubMed - indexed for MEDLINE]

ncbi.nlm.nih.gov/pubmed/251...

Full paper, as so often, behind a very high paywall.

[Clutter]

Good find, Helvella. So, the knowledge is there, but has not been taken into account when patients complain of inability to function normally.

[lb003]

Thanks for posting. Yes this is really good to see. I know that I definitely struggle with this and wonder if it may be connected to being under medicated for many years.

[adflores]

Thank you so much Helvella! This definitely explains a lot about my symptoms, and obviously, most people do not understand my exercise intolerance. Really appreciate the post!!

[Lizzy1606]

I think last year or the year before that someone put a site up that someone was trying to get funding for research into hypothyroidism and exercise intolerance (Bristol somewhere)there was also a questionaire.

[Spanglysplash]

Brilliant article! I really hope I'm not one of those that the exercise intolerance isn't reversible with hormone replacement. I want to get back to having adventures

[dolphin5]

It's a shame that the paper isn't readily available. I've been on thyroxine after my second partial thyroidectomy about 15 years ago. The dose I take allows me to do low levels of exercise, but to do long cycle rides (30-75 miles) I need to take an extra 25mcg in the morning. This allows me to do the ride, but unless we're having a heatwave, I still struggle towards the end. (It appears that when I don't need masses of thyroxine to keep warm, there is more available for my muscles.) I have been unable to do long walks since the thyroidectomy (no rests like the freewheeling when cycling). It's amazing that doctors don't understand the fact that your body uses more thyroxine when you increase your activity level. It is surely no surprise that people who are under-treated can't exercise at all. I'm lucky enough to have been prescribed an adequate dose at the outset, and to have been told to try the extra 25mcg for demanding exercise. I now just have to do battle regularly to stop doctors dropping my dose! Interestingly, I am currently doing lots of exercises prescribed by my physio since knee surgery, and I am once again exhausted, and clearly need extra thryroxine to cope with extra daily activity. I just have to wait until I've had my next blood test, or the fight with the endocrinologist will be harder to deal with!

[greygoose in reply to dolphin5]

Actually, the body uses more T3 when exercising, so not only do you have to be on a decent dose of T4, but you also have to be a good converter. And, despite what doctors think, that's not the case for everyone!

[dolphin5 in reply to greygoose]

That's what I keep telling the GPs and endo, but the GPs don't understand, and the endo isn't interested in T3!!!! Anyway, I've just started taking vit D to see if I can become a better converter. It's worth a try! (Thanks to those on this website who alerted me to the role of vit D in relation to the convertion.)

[shaws Administrator]

Great link and great find.

[MariLiz]

This is really interesting, as I'm struggling with this a lot at the moment. It is the start of the bowls season, and I played 12 ends last night in a practice session. Today I'm completely wiped out and in pain. If it continues like this I'll be forced to give up playing completely. I also do Yoga, and after my last class I came home feeling as though I'd run a marathon. I fell asleep in the afternoon. I don't want to stop either of these activities, but my body is telling me I just can't do it! MariLiz

[Ruby1]

It seems logical to me that our everyday dose of thyroxine won't enable us to cope when we ask more of our bodies. I've always enjoyed sport and I really noticed how I would feel wiped out after exercise.

I do think as you get fitter, you cope better.. or at least that is how it seems to me... you just need to accept that until you get fitter, you will be wiped out after exercise. I also think this is true for everyone, it's just that we hypothyroid sufferers get it ten fold!

[greygoose]

"As a consequence, despite a defined euthyroid status, there remains a significant group of treated patients with persistent complaints related to exercise intolerance"

That sounds like me! At last! Someone has recognised that I do have a legitimat problem, and I'm not just lazy!!!

Good article, thank you, Rod.