The Other T-hormone
An in Depth Look at Thyroid Hormones
by Arik Orosz

Have you been training and dieting like Rocky Balboa and can't seem to lose another bloody pound? Tried everything short of utilizing Dr. Bruce "King Lipo" Nadler's services to shed unwanted bodyfat? Perhaps its time to begin the metabolic troubleshooting process and get to the bottom of it all. Now I think we can all agree that testosterone is pretty important stuff and it's definitely our favorite hormone here at Shapeshifter, but it's not the only coveted T-hormone in town. The thyroid hormones are in a league all their own when it comes to dumping bodyfat. The thyroid is a small butterfly-shaped gland that is connected to the trachea just below the larynx. It secretes a tyrosine-based hormone called T4 (thyroxine). T3 (triiodothyronine) is then formed at the target tissues by the enzymatic removal of an iodine atom. T3 is about 10 times as metabolically active as T4. The amount of T4 secreted is primarily based on how much TSH (thyroid stimulating hormone) is secreted by the anterior pituitary. The ratio of T4 to T3 in the blood is usually around 4 to 1. The body will create more T3 as needed by ridding a T4 hormone of a single iodine atom. What does all this jargon amount to? The thyroid is one of the most important hormones in the body. It controls our fat-burning furnaces, aids in protein synthesis, and plays some role in nearly every body system. The problem is, the thyroid is often times the first gland to get caught in the ugly hormonal crossfire during a calorie-restricted diet. There are several circumstances that occur in the body during a diet that may aggravate these feedback loops. Let's look at some of the common culprits in this scenario, so that hopefully we may avoid some of these hormonal pitfalls before they occur.

Culprit number one - Muscle catabolism

One of the most common mistakes trainees make when dieting for fat loss is not adjusting the lifting protocol accordingly. If you are continually training with maximal poundage and lower rep brackets there is no way around the increased demand for glycogen replenishment. We must consider that heavy, low rep training primarily targets the fast twitch fibers. Fast twitch fibers are naturally larger than slow twitch fibers. In accordance with this, they have the capability to store greater amounts of glycogen and creatine. Therefore when the fast twitch fibers are depleted, we lose a greater amount of overall glycogen from the body. A lower carb regimen will most likely not satisfy these demands for reloading glycogen in these muscle fibers. This is why for years, many successful bodybuilders have switched over to a training protocol that places more emphasis on the slow twitch fibers during a fat loss regimen, i.e. high reps and shorter rest intervals. Does this mean to negate heavy lifting altogether during a diet? Not necessarily. The basic rule of thumb is this: Don't use up what you can't put back in the muscle. For most dieters, starting the workout with one heavy, compound movement will be adequate to maintain stimulus of the fast twitch fibers without overdoing it. Overtraining will result in the increased conversion of skeletal muscle proteins to glucose. This is one of the first events that signals the thyroid to pull back in order to preserve muscle tissue. Unfortunately, the end result is increased preservation of bodyfat.

Culprit number two - Low liver glycogen stores

When liver glycogen stores run empty, the immediate response is for the body to pull back on the lyzosomal enzyme supply that converts T4 to T3. Research has shown that prolonged reduced calorie/carbohydrate levels tends not to affect overall T4 levels but rather the conversion of T4 to T3 as well as a reduction in TSH levels. So why is it that most prescriptions for thyroid meds tend to always be Synthroid (a T4 med)? If conversion is the problem then adding more T4 is not going to help matters any. It's like trying to build a fire with plenty of wood and no flame. Adding more wood to the pile isn't going to increase your odds any. One natural method of avoiding this situation is simply to put some carbs back in the body after your workouts. It's not the be-all-end-all solution, but it's something that many people are not doing the way they should be, even on a low carb diet. If dietary carbohydrates are low for five out of six meals, this provides plenty of time for the body to operate in a low insulin/high glugagon environment and stimulate lipolysis. Raising insulin four or so times a week (after lifting) is not going to slow down fat loss, and in fact should help substantially by inhibiting excessive cortisol, and keeping T3 levels up.

Culprit number three - Thermogenics/Beta-Adrenergic agonists

While thermogenics may be a very useful dieting tool at times, they must be respected and treated accordingly. Most thermos on the market are some combination of ma huang, sida cordifolia,green tea extract, guarana, kola nut, synephrine, or norephedrine. These products are all beta-agonists of some kind and help to increase caloric expenditure via adrenal stimulation. These can really be useful to the dieter in overcoming plateaus where the body just doesn't want to let go of anymore fat. So what does this have to do with the thyroid? The body constantly craves a stable internal environment. One intricate variable in this environment is body temperature. If the body temperature (hence the metabolism) is increased through adrenal stimulation, its only choice for defense of homeostatic conditions is to pull back on thyroid hormones in an attempt to stabilize body temperature. Unfortunately this also throws a major monkey wrench in our fat loss program as well. Gugglesterone, an Ayurvedic herb, has been shown to keep T4 to T3 conversion levels up under these circumstances, as well as reduce LDL (bad cholesterol) levels. Nobody knows for sure how long it keeps working, as most good things eventually come to an end, but it should definitely help avoid that initial fat loss plateau. Phosphate blends, such as those added to Prolab's Thyrolean product also seem to help the thyroid in a low liver glycogen environment. This probably demonstrates the importance of maintaining adequate phosphate stores during the course of the diet. Many dieters have had moderate success using a kelp supplement to supply the body with extra iodine (a critical component of thyroid hormones). Brock Strasser's hypothesis about TML-2 (thyroid modulating ligand) sounds like a dieters dream come true, but until it becomes available we'll just have to hang tight with good old guggle.

Know your Enemy!

There you have it, the number one enemy (thyroid shutdown) that keeps even the most disciplined dieters away from ever hitting those coveted single-digit bodyfat percentages. This is not the be-all-end-all of dietary troubleshooting, but it should be a really good start. As great as it feels to set a goal and achieve it, we must learn to enjoy the process as well. Have fun learning your body and what makes it tick. The more obstacles we encounter, the more knowledge we must acquire to overcome them. When you do overcome them, you'll know you've earned it.