Understanding what hormones regulate your metabolism is the first step in learning how to set your body up for optimal fat loss. Everyone has a unique resting metabolic rate determined by the amount of lean muscle they have, genetics (DNA makeup), and hormonal balances.
The secret to successfully increasing your metabolism and burning fat revolves around creating the optimal hormonal balances for maximizing your metabolic rate.
You probably already know that calorie restriction dieting can cause your metabolism to slow down and bring weight loss to a halt. The good news is metabolic slowdown doesnâ€™t have to happen. Once you understand why it happens, you can take a number of steps to avoid it.
Regulating thyroid hormone levels is the cornerstone to keeping your metabolism running on high. The thyroid gland is the main regulator of your overall metabolism. It sets your body temperature after the hypothalamus says make it so.
The role of thyroid hormonesâ€¦
The thyroid gland secretes two types of thyroid hormones, T4 and T3. Although most of the thyroid hormone in blood circulation is T4, itâ€™s T3 that really produces the most impact. At the cellular level, T3 is the one that hooks up to the receptors and makes everything work.
The main cause of metabolic slowdown is a decrease in active thyroid hormone. There are three main reasons why thyroid hormone levels will go down.
1.Â The loss of lean muscle
The loss of lean muscle comes from a lack of resistance training, protein deficiency, and low calorie diets that force the body to break down muscle tissue.Â There are also hormonal changes in estrogen and testosterone that naturally decline as you age that can create muscle loss. The good news is you have a significant degree of control over all these factors.
2.Â Increased production of cortisol
The second cause of thyroid hormone attenuation is the increase in cortisol levels. Cortisol is a hormone produced by the adrenal glands in response to psychological and physiological stress. When the cortisol receptors on the pituitary gland are activated, they reduce production of thyroid stimulating hormone (TSH), which is the messenger between the hypothalamus and the thyroid gland.
Cortisol also affects the conversion process of T4 (circulating thyroid hormone), to T3 (the thyroid hormone that hooks up to the receptors). Stress, overtraining, low calorie diets, and a lack of sleep all contribute to the increase in cortisol and a decrease in thyroid hormone production.
3.Â Increased production of insulin
The third cause of decreased thyroid hormone production is the constant presence of insulin. The pancreas secretes insulin in response to high blood sugar levels. If the body experiences high blood sugar levels on a regular basis (too much carbohydrate in the diet) the cells start to reduce the acceptance of insulin. This is commonly referred to as insulin resistance. The resulting over-secretion of insulin causes cortisol levels to rise which as you just learned can reduce thyroid hormone production.
Bottom line is the lack of lean muscle (from all the causes), too much stress (no matter what the trigger), and a poor diet can all contribute to a decreased thyroid hormone production and slowed metabolism.
Growth hormone, adrenaline and nor-adrenaline
Your metabolism is also regulated by the balances of powerful fat burning hormones which can be increased with the right type of exercise. The right type of exercise? Yes, while all exercise is beneficial, itâ€™s high intensity- short duration exercise that produces the best results.
This is commonly referred to as â€śburst training,â€ť and â€śinterval training.â€ť These high intensity- short duration types of exercise will cause an increase in growth hormone and the adrenal hormones; adrenaline and nor-adrenaline.
Traditional long-slow-distance cardio (aerobic training), and low-intensity resistance workouts simply wonâ€™t produce the same hormonal response.
Optimizing your metabolic rate
As youâ€™ve learned there are some obvious things you can do to optimize your metabolic rate:
- perform burst training (resistance workouts) and interval training (cardio workouts) to raise growth hormone, adrenaline, and nor-adrenaline levels.
- avoid low calorie diets that can reduce thyroid hormone production
- minimize stress to avoid excess cortisol production
- reduce insulin levels by eating a supportive nutrition diet with moderate levels of carbohydrates.
- increase protein intake to help with lean muscle development and prevent muscle catabolism
- get plenty of sleep (7-8 hours) to help with growth hormone secretion and reduce the production of cortisol.
While this is a solid set of guidelines to help you increase your metabolic rate, there are instances of decreased thyroid hormone production that will require prescription medication treatment from your physician.
If you suspect decreased thyroid hormone production there are three specific tests you should request from your physician.
Thyroid Stimulating Hormone (TSH) Test
Free T4 Test
Free T3 Test
Just looking at one test alone is a poor strategy. All three tests are needed to see whatâ€™s really going on. Youâ€™ll also want to find physician who will work with you to optimize your thyroid levels, not just look to see if youâ€™re in the â€śnormal ranges.â€ť
Here is a physician I work with regularly in the Charleston area that specializes in hormone replacement therapies:
Resting metabolic rate testing
A good starting point to assessing your metabolism is through a metabolic profile assessment. Shaping Concepts is a provider of this metabolism test through the use of the Korr Metacheck analyzer.
The test is easy to complete and takes less than 20 minutes to conduct. You simply sit back in a reclined chair and breathe through a tube to measure your oxygen consumption. The analyzer does the rest and once complete youâ€™ll know the number of calories your body burns at rest and what your ideal calorie window is for fat loss.
If your resting metabolic rate is slow itâ€™s a pretty good indicator that your thyroid production has decreased. Weâ€™ll make changes to your diet and exercise to begin reversing the slowed metabolism and make recommendations for further testing with one of our advisory board physicians when needed.
Fat loss is 100% controlled by the hormonal balances in your body. Hopefully this article has helped you better understand the hormonal connection to your metabolism.
Shane Doll is a certifed CharlestonÂ personal trainer, fat loss expert,Â speaker and founder of Shaping Concepts Personal Training Studios. Shane is available for thoughtful and candid interviews onÂ weight loss and fitness related subjects.