I’ve been doing a lot of blood work for physique competitors these past few months. In fact, I’ve worked with more competitors this year than ever before. Because of this, I see patterns universal across every division. One in particular is how the thyroid starts to respond as a contest gets closer. Free T3 (active thyroid hormone) levels can drop quite dramatically, putting a halt on any fat loss. If a competitor (or really any individual wanting to lose weight) isn’t consuming adequate amounts of calories (usually in a deficit >1,000), the body starts to produce reverse T3 – think of this as a mirrored form of T3. Most labs place their reference range between 10-24 ng/dL – anything over 15, and you’ll start to see fat loss slow down. These levels rise in an attempt to put the brakes on energy expenditure. Oh, an along with this, leptin resistance tends to follow. Stress is a big driver for the conversion of T4 to reverse T3 – so, elevation in this is likely. Exogenous growth hormone seems to mitigate this, pushing forth T4 to T3, minimizing it’s conversion to reverse T3. Supplemental T4/T3 (this depends largely on lab work, but an approximate 4:1 ratio is typical), iodide (somewhere between 6.25 and 12.5 mg), selenium (<400 mcg), and zinc (around 60 mg) can be used, but this wouldn’t necessarily be my default approach in correcting this (given that you have enough time left in your prep).
If reverse T3 levels are high, this is a pretty good indicator that your caloric intake is too low. So, initially I would have a client bring some food back into their diet (check my post on Diet Breaks). Fat loss does not directly correlate with calorie restriction – you can’t expect more fat to be lost with more dramatic reductions in calories. There will be, at some point, diminishing returns. Your body has plenty of mechanisms set in place to prevent changes it deems “dangerous” and not eating enough fits the bill. I get it, I really do – we all want to win. But competitiveness coupled with high cortisol clouds judgement. The next step would be to reduce inflammation – inflammation will, always, decrease the conversion of T4 to T3 and increase levels of reverse T3. I’ll have to dive into this (and leptin resistance) at another time as it’s a pretty big topic.
References
Childs, W. (n.d.). [Digital image]. Retrieved from https://i1.wp.com/www.restartmed.com/wp-content/uploads/2016/04/Euthyroid-sick-syndrome-lab-values.png?resize=411,325&ssl=1
Thoughts?