Does being active affect T3 conversion?

[JPM90]

Hi everyone

I was just wondering if anyone could tell me if your activity levels affects your body converting T4 into T3?

Does doing any exercise (walking, running, weight lifting etc) make the body convert more t4 into t3?

[greygoose]

More likely to make it convert less because you're using up the calories needed for conversion.

[golfmargaret in reply to greygoose]

Yes!

[Lalatoot]

In a healthy person with no thyroid problems, yes.In a person on replacement thyroid hormones exercise and fuelling that exercise becomes trickier and more of a balancing act.

A normal thyroid adjusts hormone levels throughout the day but we are reliant on how much we dose with and when we dose. So we first have to have our TSH, ft4 and ft3 levels optimal.

Even with optimal levels we may not have the adaptability in our system to exercise as we once did. We might need to change the type of exercise we do as well as the frequency and recovery time.

We also need adequate calories. Calories are needed to fuel the exercise but we also need calories to convert t4 to t3.

By exercising too much we can impair conversion.

[tattybogle]

healthunlocked.com/thyroidu... the-effect-of-acute-exercise-session-on-thyroid-hormone-economy-in-rats

You might find this post ,and the study it refers to , interesting.

[jimh111]

I looked into this a while ago, along with other factors such as time of day, time of month, cold exposure etc. Going from memory exercise had a small effect on conversion, as did cold exposure. It was very small.

I find exercising helps overcome my hypothyroidism, mitigates effects such as fatigue and brain fog. I guess this applies to everyone not just hypothyroids.

Thyroid hormone binding to receptors produces proteins that do all sorts of things, including providing energy and tissue repair. If we overdo it we use up these resources and of course if we are still a little hypo we produce these resources at a slower rate. (My view but I don't believe we 'use up' the T3, I think we use up the substances that T3 helps produce because when hypo our metabolism runs slower.)

I did read papers addressing exercise and deiodinase but don't have them to hand or time to search again. I found them using a PubMed search 'exercise deiodinase'.