Natural Ways to Increase Testosterone Bioavailability in Athletes

Being a natural athlete I’ve always sought to find more ways to increase testosterone levels naturally. The question I’ve always asked myself was: what are the variables that determine how much testosterone is bioavailable?

Testosterone & Natural Bodybuilding

I’ve read articles about testosterone before. They gave limited advice on what causes test levels to go up or go down. But after an extensive search I couldn’t find the article I was looking for.  I wanted one that explained things in detail. Such as, how and what I should manipulate directly in my system to achieve the effects I desired. In addition, how to get higher levels of circulating testosterone. Also, how much of it will be available to the corresponding receptors in the cell walls. Moreover, I wanted to know all this in regards to natural bodybuilding.

So, I decided to do some good digging and reading. Then I wanted to lay that out in writing form. That way, others can benefit as well.

What Is Testosterone?

Before we look at how to increase testosterone, let’s look at what it is. Testosterone is a steroid hormone. It has anabolic and androgenic properties. Furthermore, it occurs naturally in the body. First, it is the main hormone responsible for increasing lean muscle tissue. Second, it increases libido, energy, bone formation, and immune function.

Testosterone is secreted in the testes in men and in the ovaries in women. In addition, small amounts are also secreted in the adrenal glands. Further, testosterone is derived from cholesterol. The levels of testosterone in men range between 350 and 1,000 nanograms per deciliter (ng/dl). After the age of 40 these levels drop by roughly 1% a year.

Testosterone Is Not Always Available

Testosterone circulates in the bloodstream and is bound to binding proteins. Sex Hormone Binding Globulin or SHBG is the one that concerns us the greatest. Why? Because this is the main reason why testosterone might not be available to reach the cell receptor. When testosterone gets attached to SHBG, it no longer performs its anabolic functions. It goes without saying, that’s not going to help us increase testosterone.

What Elevates SHBG:

Anorexia nervosa, Hyperthyroidism, Hypogonadism (males), and Androgen insensitivity/deficiency. Also Alcoholic hepatic cirrhosis (males), Primary biliary cirrhosis (females).

What Suppresses SHBG:

Obesity, Hypothyroidism, Hirsutism (females), and Acne vulgaris Also Polycystic ovarian disease, Acromegaly, Androgen-secreting ovarian tumors.

Less than 1% of the circulating testosterone is in a free form in males (less than 3% in females). Only when in a free form this hormone can exhibit its properties. It does this by connecting to the androgen receptors on the cell walls. Based on a study 14 to 50 % of the testosterone is bound to SHBG in males. It’s 37 to 75 % in females. It is worth mentioning that SHBG has a very high affinity for binding to testosterone. Therefore, changes in the SHBG levels noticeably influence the level of bioavailable testosterone.

Increase Testosterone Naturally – What About Bioavailability?

Let’s discuss testosterone bioavailability. Other than SHBG there are two more testosterone-binding proteins, also called carriers. One of them is albumin. It is a low-affinity binding protein. Testosterone bound to it is considered “bioavailable”. Albumin binds to testosterone in the range 45 to 85 % in men. It’s 25 – 65 % in women. The third carrier is the cortisol binding globulin. This binds with low-affinity to less than 1 % of the testosterone in circulation.

The free androgen index (FAI) indicates the amount of bioavailable testosterone. FAI is the sum of: free testosterone, albumin and cortisol binding globulin. Or, it’s the total serum testosterone minus the SHBG-bound testosterone.

Increase Testosterone – What About SHGB?

It is now clear why we should focus our attention on the properties of SHGB. The levels of this binding protein increase when there is excess estrogen present. Moreover, SHGB levels drop if the testosterone levels are elevated. SHGB exhibits higher affinity to testosterone than to estrogen. Now, pay close attention.

It’s a well-known fact that testosterone is an estrogen precursor. It will convert to estrogen under the influence of the enzyme aromatase. Nothing that we don’t know so far. Here is where it gets interesting. Suppose that we have normal testosterone levels. We don’t suffer from any of the health ailments, which influence SHGB levels. Finally, that means that SHGB levels are normal, too.

SHGB & Estrogen

If more of this testosterone is converted to estrogen due to abnormal aromatase levels, SHGB will increase as well. SHGB is more readily bound to testosterone. However, that will leave us with excess estrogen levels in the system. This in turn will stimulate increased production of the SHGB protein from the liver. This whole process amplifies estrogen levels. Estrogen readily binds to the androgen receptors in cells. This leaves less opportunity for free testosterone. Finally, estrogen is the messenger molecule that signals the brain to decrease testosterone production.

Also, over 40 % of SHGB protein circulates unbound in the bloodstream in men. It’s over 80 % in women. In addition, albumin circulates unbound almost all of the time. This increase in total testosterone levels does not produce any noticeable changes in the free testosterone levels. That is, unless there is a significant increase like the one seen after synthetic steroid hormone administration.

Here’s How A Natural Bodybuilder Can Increase Testosterone:

  • Prevent testosterone levels from getting low
  • Attempt to increase the total testosterone as a means of keeping the testosterone levels from plunging
  • Block the testosterone-binding effects of SHBG
  • Lower the levels of the enzyme aromatase – less testosterone conversion to estrogen

1. What Causes Testosterone Levels To Get Too Low?

  • Obesity. Based on the way the testosterone-estrogen mechanism works, increased levels of estrogen will ultimately decrease the circulating testosterone. Excess fat causes more estrogen production. This is due to the fact that fat cells manufacture estrogen. So, the more fat cells, the more estrogen in the blood, and the less testosterone. As you can see, losing fat makes a lot of sense.
  • Drug and alcohol abuse. Alcohol inhibits your ability to remove estrogen from the bloodstream. It does this by acting as a central nervous system depressant. It also decreases zinc levels.
  • Stress elevates corticosteroid levels in the bloodstream, which causes the testosterone levels to decrease.
  • Medications. Some medications, including estrogen and progesterone, lower the luteinizing hormone (LH) levels. LH is the hormone responsible for steroid hormone production.
  • Diabetes. Studies suggest that there is a link between type 2 diabetes and lower testosterone levels.
  • Hypertension and high cholesterol levels. These both cause the arteries to harden. This decreases blood flow to the sex hormone-producing organs. That of course leads to low sex hormone levels.
  • Aging. The fact is after the age of 40 test levels drop by roughly one % per year. We can’t do too much about that. The clock keeps ticking for all of us. However, we can try to manipulate testosterone levels in other possible ways.

  • Low-fat diet. Low-fat consumption causes an increase of the SHGB, which means one thing – less free testosterone. Monounsaturated fats play an important role in testosterone levels and bioavailability.
  • Overtraining can contribute to as much as a 40 percent drop in testosterone levels. That is why it’s important to notice early signs of overtraining. It’s important to give the body a week or two of well-deserved rest.
  • Not enough sleep. Do you get enough sleep? If not, the body is not recuperating well. This causes less testosterone and more corticosteroids to be released. Corticosteroids like cortisol are in fact catabolic hormones. This means they use up muscle tissue to provide the brain and the heart with energy.
  • Vitamin C. Are you taking enough C? You should be. Why? It suppresses the release of the stress hormone cortisol. Cortisol decreases testosterone levels. So, ultimately less cortisol means more testosterone.

2. How To Increase Testosterone Levels

  • Incorporate basic movements that involve several muscle groups in your training routine. Good choices include squats, deadlifts, and military presses. Basic (compound) exercises have been shown to play an important role in testosterone levels.
  • What causes the greatest workout-related testosterone production? The use of heavier weights and lower rep range. A study shows that the best is 85 percent of your one-rep max.
  • Try a natural test booster. One of the best is Just Test Me by Spazmatic Supplements.

You can check it out here: Spazmatic Supplements Just Test Me! All-In-One-Testosterone Booster – I’ll Pump You Up (

3. Block The Testosterone-Binding Effects Of SHBG

  • Nettle root as a highly concentrated extract has shown to be effective at binding to SHBG. Therefore, it permits more free testosterone to circulate the system. It also acts as a 5-alpha reductase inhibitor. This is the enzyme responsible for the conversion of testosterone to dihydrotestosterone (DHT). That’s a more potent form of the male sex hormone, which causes prostate enlargement and ultimately cancer. Methanolic extract of nettle can also cut down the SHBG levels. This is another way of elevating the free testosterone in the bloodstream.
  • Pygeum (prunus africana) is another herb. It’s known to block the testosterone-binding effects of SHBG. Nettle root and pygeum extracts also benefit the prostate gland. They act as a preventive treatment for benign prostatic hyperplasia (BPH). They both do this by blocking the 5-alpha reductase action.
  • Avena Sativa is an extract from the straw of oats. It has somewhat different properties. It works by freeing bound testosterone, which increases the free testosterone in circulation.

4. Lowering Aromatize Levels

  • Zinc. The mineral zinc inhibits the aromatase enzyme that converts testosterone into excess estrogen. The recommended dose for inhibiting aromatase is 80mg daily. However, be sure the combined zinc quantity of all the daily supplements you are taking does not go over this benchmark.
  • Chrysin is a bioflavonoid that has shown potential as a natural aromatase inhibitor. Chrysin is poorly absorbed in the system. It is found that when taken along with piperine, chrysin exhibits a lot better absorption. Supplementation with chrysin and piperine together might bring good results in reducing aromatase levels.

Testosterone & Natural Bodybuilding

Let’s assume you are a natural bodybuilder wondering how to increase testosterone. You do not want to use steroids. You do want to make the most of your own natural testosterone production.

Here Is What You Do:

  1. If you are even slightly overweight, start a fat loss diet and training routine. Make sure you train for mass even though you’re cutting calories.
  2. Drop the alcohol. Or at least cut back. Of course
  3. Begin mastering some types of self-control or even meditation. These will take care of the excess stress levels.
  4. Take medications only if they are absolutely essential for your health. Take them only if they are prescribed by your doctor. Talk to your personal physician to find out if there are any natural remedies to replace your current medications. Ask if he recommends such an approach for your health issue.
  5. Start relying more heavily on basic exercise movements. Train in the low rep range most of the time. 5 – 8 reps will ensure that you’re using weights that stimulate elevated testosterone levels.

  6. Keep your blood pressure and serum cholesterol in check.
  7. Eat enough good fats in your diet. Good means monounsaturated and omega-3 and 6 polyunsaturated fats.
  8. Don’t ever overtrain. Sleep enough to promote good recovery. Signs of overtraining are loss of appetite, tiredness and irritability. Also, a lack of motivation, impaired mental focus, prolonged recovery periods.
  9. Take that test booster! Add in a good estrogen blocker also: 5% Nutrition Post Gear – I’ll Pump You Up (
  10. Don’t even consider training without supplementing your diet with enough vitamin C (at least 1g a day) and zinc (15mg min.). Take vitamin C with your multivitamin formula after breakfast, and post-workout with your protein shake. Zinc should be present in your multivitamin blend but this is not enough. Take zinc with magnesium in the form of ZMA right before you go to bed on an empty stomach.


Ron Geraci, Men’s Health, December 25, 2000; 13 Ways to Naturally Boost Your Testosterone Levels

LE Magazine January 2000; Replenish Testosterone Naturally

Plant extracts favorably alter hormone metabolism and improve sexual desire in men

Jennifer A. Kelly, Ph.D. and Leo Vankrieken, Eur. Eng. Diagnostic Products Corporation; Sex Hormone Binding Globulin and the Assessment of Androgen Status; Avena Sativa – are oats an aphrodisiac?

Gabe Mirkin, M.D.; High Cholesterol Causes Low Testosterone


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