Boost Testosterone Naturally
A Superior Formula for Enhancing Our Most Prized Anabolic Hormone (With Minimal Fuss and Minimal Equipment)
It is not for nothing that testosterone is considered to be the King of muscle-building hormones. With its well-earned status as the body’s preeminent size-enhancer, it comes as no surprise that most lifters – from beginner to advanced – are ever on the lookout for newer and faster ways to maximize its production. But boosting the coveted T can be complex and costly. Certain test-enhancing methods can even damage the very vessel it is designed to improve.
For most healthy lifters, testosterone is produced in sufficient enough quantities to ensure steady size and strength gains. Regardless, there are those who will do almost anything to flood their muscles with as much of it as possible, irrespective of their existing T status.
This can mean taking anabolic drugs (various synthetically-derived forms of testosterone) or training in specific ways (with a focus on heavy compound movements in particular). But not everyone can or is indeed willing to go either of these routes. Fortunately, however, there are several superior T-boosting alternatives that can give you the results you want without exacting any unwanted costs (and by superior we mean more cost effective, easier to incorporate, healthier for the body, and longer lasting).
We explores four such alternatives, to demonstrate how our most revered mass-building hormone can be maximally increased without traditional hardcore training precepts or potentially damaging substances. Followed consistently, the steps outlined below will naturally up regulate your testo, to give you the long-lasting gains you have always wanted, less weight gain and zinc deficient.
Why Boost Testosterone?
As touched on above, testosterone’s impact on the body is both far-reaching and beneficial on many levels. It is involved in much more than muscle growth, its daily production affecting in some way virtually every function of importance to the health and wellbeing of hard training athletes and regular trainees alike. And while men produce around 20 times more testosterone than females, it is nevertheless important for both sexes, making it a hormone all of us could probably do with more of.
Just as many functions are affected by testosterone there are also a great many ways to increase its production. Below are four fail-safe methods that virtually anyone can incorporate on a daily basis to naturally boost their supply.
As mentioned, most healthy lifters naturally produce enough testosterone to support their weight room endeavors. If this is the case, then why seek to further increase adrenal glands? Before diving into various ways we might naturally boost T, let’s take quick look at why serious lifters should do all they can (within reason) to increase this anabolic hormone par excellence to the highest possible degree.
Testosterone works its muscle-building magic firstly by stimulating androgen receptor molecules in muscle cells. Once switched on, these molecules activate specific protein-producing genes contained within these cells’ nucleus – a process otherwise known as the anabolic effect; an effect that has given rise to the concept of muscle anabolism (the desired constructive metabolism all bodybuilders seek).49
In addition, testosterone up-regulates protein metabolism to increase muscle protein synthesis while offsetting muscle protein degradation – a process otherwise known as the anti-catabolic effect. As such, testosterone’s main muscle-building benefits are both anabolic and anti-catabolic, both of which are necessary for the complete stimulation, restoration, and ultimate growth of muscle tissue.1, 7
Testosterone also enables the lifter to train with more intensity partly as a result of a corresponding increase in ATP (Adenosine Triphosphate: a coenzyme that carries energy within cells) and enhanced cognition (including a positive mindset and feelings of confidence and wellbeing).40, 53 In short, besides enjoying a pronounced physiological advantage, those with higher than normal testosterone are generally considered to be more aggressive and confident, traits that bode well for advanced training success.
Indeed, greater levels of testosterone lend a psychological advantage that has equipped humans with a propensity to survive hostile environments since the beginning of human evolution. It is no great stretch to say that without sufficient levels of circulating T, survival itself (much less the ability to thrive and conquer) would not have been possible.
In addition to enabling us to conquer the weights with maximum aggression and intensity, testosterone has also been shown to increase the glycoprotein cytokine EPO (erythropoietin), which stimulates the formation of red blood cells.6, 41With high levels red blood cells, boost your testosterone levels with more oxygen can be transported within the blood to ensure that our muscles can be made to work both harder and for longer.
Further adding to its endurance capabilities is testosterone’s ability to increase the number mitochondria (fat-burning and energy producing organelles) within muscle cells while also improving mitochondrial function.19 This makes T not only essential to strength and power output (and muscle-building, both directly and indirectly), but also of importance to optimizing performance, and health, generally.31, 36, 39, 59, 63, 65, 66
Speaking of health benefits, testosterone also works to obliterate bodyfat by blocking the uptake and storage of fat. It does this by increasing the number of fat-burning beta-adrenergic receptors.15, 16 As a result, beta-subunits of the adrenergic receptors (targets of ephedrine) work to stimulate fat loss by increasing the activity of an enzyme called adenyl cyclase increases testosterone levels.
It has further been shown that suboptimal testosterone levels can disrupt metabolism (thus stifling caloric-expenditure) and decrease insulin sensitivity to negate nutrient partitioning, both of which can negatively impact body composition.23, 35
Closely aligned with nutrition is supplementation, which, it could be said, is of equal importance (and in some cases of greater importance) to enhancing testosterone production.
Supplements of specific importance to increasing T levels include those that help to round out our macronutrient balance to ensure a more complete ratio of nutrients throughout the day (in a more easily assimilated and bioavailable manner). The following three supplements have been shown to enhance nutrient balance while optimizing performance and hormonal status:
ISOFLEX a high-grade whey isolate protein formulation with bioactive whey fractions to enhance immunity and general health.
CARBION+ a carb formulation that contains key electrolytes, is non- insulin-spiking, and is optimally absorbed and assimilated.
ALLMAX MCT OIL a rapidly assimilated fat that is utilized for fuel rather that stored as bodyfat.
Supplementation also provides an excellent way to achieve high-dose levels of key testosterone-boosting compounds in a convenient and cost-effective manner. Trying to get each of the valuable ingredients needed to optimize test production can be all but impossible.
Take Creatine, for example. A known test booster, Creatine from whole foods is hard to obtain in the sufficiently respectable amounts needed to increase testosterone.57 However, in supplement form, sufficient Creatine (the recommended 3-5 grams per serving) can be provided in one small scoop.
As another example, take the nutrient-dense oyster. While each good-sized oyster contains on average 5.5mg of Zinc, a hard-training bodybuilder, with a recommended daily Zinc intake of 30mg, would need roughly six oysters a day to achieve a optimal dietary intake (oysters by far being the most Zinc-dense of whole foods).
Putting aside the fact that oysters can be extremely expensive, sometimes difficult to purchase (due to availability), unpalatable for some, and questionable as to exactly how much of their active Zinc component can be assimilated into the body, supplementation can provide a similar Zinc content with minimal fuss and at far less cost. In addition, you’re likely to get more of the active nutrient, to ensure steadier gains.
For those wanting a consistently well-balanced ratio of each vital testosterone-boosting nutrient, a better option is likely to be an all-in-one supplement that provides not only the specific nutrients needed to enhance T but every other nutrient of importance to synergistically enhancing the uptake of these nutrients while working in their own unique way to maximize anabolic hormone production.
To achieve this end result, the best product remains the high-potency VITASTACK. Packed with every conceivable micronutrient and anabolic co-factor necessary for increasing testosterone (including an optimal ratio of essential fatty acids, specific amino acids, and metabolic enhancers to keep the body lean and primed for maximum T production), it works to plug any nutritional gaps while also keeping the body in a highly anabolic state.
Along with the aforementioned macronutrient-based products and the advanced VITASTACK formula, can be added a specific testosterone-booster. Though many testosterone-boosting products have fallen out of favor in recent years due to poor efficacy and having more hype than substance, there is one that has scientifically proven benefits to support its ability to deliver on its claims of increasing bioavailable testosterone from 5.9% to 28.1%, when used as instructed: TESTO-FX.11, 61, 67
Crammed with high-dose and highly-bioavailable versions of Sensoril (a highly-concentrated form of the cortisol-lowering medicinal herb Ashwaganda); TORODEX (a highly specialized form of Fenugreek extract); NOVALDIM (3, 3-di-indolylmethathane, which locks up and blocks estrogen receptors, thus deactivating bad estrogen metabolites); Alpha Lipoic Acid and Myo-Inositol (to increase androgen receptor affinity to ensure a greater amount of free testosterone is captured and transported across the cell membrane); and Saw Palmetto (to counter excessive DHT production resulting from a greater influx of natural testosterone), TESTO-FX, in summary, maximizes testosterone production in the following five ways:
- Blocks the catabolic hormone cortisol.
- Enhances the production of free testosterone (testosterone’s most biologically active form).
- Inhibits estrogen production (the main female sex hormone).
- Potentiates receptor sites which specifically encourage testosterone uptake into muscle cells.
- Has powerful anti-aromatase actions (thus preventing the conversion of testosterone to estrogen) and mitigates excessive DHT production (to provide an optimal balance of testosterone to DHT which in turn promotes anabolic benefits without any harmful side effects).
It is no secret that to enhance testosterone production, some form of exercise is needed.2, 58 However, while heavy compound movements remain a proven way to maximize test levels, not everyone is suited to or able to engage in this from of training. In light of recent social distancing requirements coupled with many of us having less access to hardcore training machinery (not to mention, in certain cases and for whatever reason, an inability to lift hard and heavy), it is perhaps time to explore alternative ways to enhance our most-prized anabolic hormone.
Firstly, it is important to note that any form of exercise increases testosterone to some degree, specifically methods that emphasize weights and encourage fat loss.34 Indeed, shedding unnecessary adipose is important here as excess bodyfat restricts testosterone production via an accompanying increase in the enzyme aromatase, which in turn converts testosterone to the estrogenic steroid hormone estradiol.12 Thus, the more fat we have, the less test we may ultimately produce.
Without having access to a full gym environment or unable to engage with ultra-heavy iron, the best way to boost T is to incorporate various forms of High Intensity Interval Training (HIIT) – both cardiovascular and resistance methods.24, 27, 29, 50, 51, 56 The key here is to ensure that each HIIT-based session is relatively short, highly-focused, and ultra-intense.
Indeed, studies have shown that compared to long-duration exercise protocols, short and intensive training both stimulates test production and enhances muscle retention. Whereas longer duration sessions (typically 45 minutes or more) may utilize more muscle proteins for fuel and lead to metabolic adaptation (both counterproductive to test boosting), short and intensive training leads to more T and greater subsequent muscle gains.
HIIT is also ideal for people with limited training resources. Here, a solid set of dumbbells and an ability to complete a series of bodyweight movements is all that is needed to get in a good HIIT session. Two examples of an effective HIIT circuit are as follows:
- Tabata Bodyweight circuit: Push-Ups: 8 sets: 20 seconds of Push-Ups followed by 10 seconds rest per set (total duration: four minutes).
- Dumbbell Press-Curl Supersetted with Lateral Raise: 5 sets of 20 reps with 30 seconds rest between sets (completed as one giant circuit).
Of course, HIIT also doubles as an efficient means to removing bodyfat. Here, a typical session will have the trainee complete (via stepper, cycle, or treadmill) 20-seconds of fast-burst activity followed by 40-seconds of active recovery for a total duration of 25-30 minutes.
It is widely accepted that exercise and stress reduction go hand in hand. As such, through regular training we can both directly and indirectly increase the ‘muscle-building’ hormone by driving down unwanted stress. So, what exactly is it about stress that strips us of one of our most valuable muscle-building assets? One word: cortisol.
Regardless of the various motivating factors that underpin stress (a missed deadline, heavy traffic, an argument, or a threat to survival…), all stress responses affect the body in much the same way: by stimulating the release of the catabolic stress hormone cortisol. Therefore, whether the event that precedes a stress response is important or not has no bearing on the negative consequences of cortisol release.
Here’s how it works. As soon as the body perceives stress, the adrenals are signalled to produce cortisol. Once released into the bloodstream, cortisol gets to work elevating blood pressure and heart rate and increasing blood glucose levels, among other functions necessary for engaging the famed fight or flight response.
Unfortunately, another of cortisol’s effects is to drive down testosterone, an adaptively important step that effectively shuts down various testosterone-guided processes that may compromise survival – processes that include mating, competition, and aggression. Thus, under conditions of stress, cortisol and testosterone are increased and decreased in seesaw-like fashion; as one (cortisol) goes up, the other (testosterone) goes down.14, 18, 26, 37, 38, 48, 54
Though critical for helping us to deal with stressful situations, cortisol can nevertheless be extremely harmful to the body if not kept in check. Indeed, the chronically stressed are likely to experience compromised immune function, poor digestion, cardiovascular conditions, a supressed reproductive system and, yes, poor growth due in large part to a sustained decrease in testosterone.
Each of these negative consequences – experienced separately or when combined – are likely to promote excess bodyfat storage, poor mental health, decreased muscle mass, a reduction in strength and performance, and an increased susceptibility to illness and disease.17
When people talk about increasing testosterone, the discussion usually centers around training methods, anabolic drug intake, or that latest wonder supplement. However, by simply limiting stress and in turn offsetting the devastating consequences of chronic cortisol release, we can more safely and effectively boost our T levels and keep them consistently high.
The best ways to minimize the impact of stress include: staying calm and not overrating to trivial events (such as another person’s point of view or a particular news item); getting at least eight hours of uninterrupted sleep each night; limiting caffeine intake to no more than 3-4 cups of coffee per day; incorporating a complete vitamin-mineral supplement such as the market-leading VITASTACK to balance out our mental and hormonal state; and, of course, incorporating daily exercise.13, 20, 21, 22, 33
A sound nutrient intake remains another vitally important way to improve testosterone production. The various ways nutrition boosts T (both direct and indirect) are many and varied, each of which cannot be covered in any great detail in an article of this size. So, I’ll briefly focus on the most important of these.
Firstly, a well-balanced diet, comprising neither too many nor too few calories, encourages a healthy bodyweight and low levels of stored bodyfat (both of which encourage T production).32, 45, 52
Second, a well-balanced diet (with an optimal ratio of carbohydrates, proteins, and fats) provides the energy needed to train with full intensity and the raw materials needed for full recovery from training, each of which can also ramp up our T levels.29, 42, 46, 47, 56
Thirdly, certain foods (namely those which include Vitamin D, Zinc, Magnesium, cholesterol, and saturated fats and, to a lesser degree, Vitamins A, C, B-Complex and E) have been shown to be particularly effective for boosting testosterone.3, 4, 5, 8, 9, 10, 26, 30, 43, 44, 55, 60, 62, 64, 68 A well-balanced diet should provide each of these foods to one degree or another.
In other words, while Zinc, Magnesium, and Vitamins D, A, C, B-Complex and E-fortified foods can be consumed more liberally, cholesterol and saturated fats, though just as important for T production, are to be consumed in smaller amounts. Because it is difficult to give general advice on such matters, it is recommended that you check with your physician and have a good nutrition coach guide your efforts. But the T-boosting bottom line remains: always achieve a good balance of nutrients and do not practice either caloric restriction or overconsumption.
- Almehmadi, Y. et al. (2016). Testosterone replacement therapy improves the health-related quality of life of men diagnosed with late-onset hypogonadism. Arab J Urol. 14(1):31‐36.
- Ari Z. et al. (2004). Serum testosterone, growth hormone, and insulin-like growth factor-1 levels, mental reaction time, and maximal aerobic exercise in sedentary and long-term physically trained elderly males. Int J Neurosci. 114(5):623‐637.
- Akmal, M. et al. (2006). Improvement in human semen quality after oral supplementation of vitamin C. J Med Food. 9(3):440‐442.
- Bishop, D.T. et al. (1988). The effect of nutritional factors on sex hormone levels in male twins. Genet Epidemiol. 1988;5(1):43‐59.
- Bélanger, A. et al. (1989). Influence of diet on plasma steroids and sex hormone-binding globulin levels in adult men. J Steroid Biochem. 32(6):829‐833.
- Bachman, E. et al. (2014). Testosterone induces erythrocytosis via increased erythropoietin and suppressed hepcidin: evidence for a new erythropoietin/hemoglobin set point. J Gerontol A Biol Sci Med Sci. 69(6):725‐735.
- Bhasin, S. et al. (1997). Testosterone replacement increases fat-free mass and muscle size in hypogonadal men. J Clin Endocrinol Metab. 82(2):407‐413.
- Bischoff-Ferrari, H.A. et al. (2008). Additive benefit of higher testosterone levels and vitamin D plus calcium supplementation in regard to fall risk reduction among older men and women. Osteoporos Int.19(9):1307‐1314.
- Braun, A. et al. (2011). Association of low serum 25-hydroxyvitamin D levels and mortality in the critically ill. Crit Care Med. 39(4):671‐677.
- Bishop, D.T. et al. (1988). The effect of nutritional factors on sex hormone levels in male twins. Genet Epidemiol. 5(1):43‐59.
- Capasso, I. et al. Combination of inositol and alpha lipoic acid in metabolic syndrome-affected women: a randomized placebo-controlled trial. Trials. 2013; 14: 273.
- P.G. (2001). Aromatase, adiposity, aging and disease. The hypogonadal-metabolic-atherogenic-disease and aging connection. Med Hypotheses. 56(6):702‐708.
- Cook, C. et al. (2012). Acute caffeine ingestion’s increase of voluntarily chosen resistance-training load after limited sleep. Int J Sport Nutr Exerc Metab. 22(3):157‐164.
- Cumming, D.C. et al. (1983). Acute suppression of circulating testosterone levels by cortisol in men. J Clin Endocrinol Metab. 57(3):671‐673.
- Douris, N. et al. (2017). Beta-adrenergic receptors are critical for weight loss but not for other metabolic adaptations to the consumption of a ketogenic diet in male mice. Molecular metabolism, 6(8), 854–862.
- El-Zayat, S. R. et al. (2019). Physiological process of fat loss Bulletin of the National Research Centre volume43, Article number: 208
- Epel, E.E. et al. (1999). Stress-induced cortisol, mood, and fat distribution in men. Obes Res. 7(1):9‐15.
- Epel, E.S. et al. (2006). Cell aging in relation to stress arousal and cardiovascular disease risk factors. Psychoneuroendocrinology. 31(3):277‐287.
- Guo, W. et al. (2012). Testosterone plus low-intensity physical training in late life improves functional performance, skeletal muscle mitochondrial biogenesis, and mitochondrial quality control in male mice. PLoS One, 7(12), e51180.
- Granata, A.R. et al. (1997). Relationship between sleep-related erections and testosterone levels in men. J Androl. 18(5):522‐527.
- Goh, V.H. et al. (2010). Sleep, sex steroid hormones, sexual activities, and aging in Asian men. J Androl. 31(2):131‐137.
- Goldman, S.E. et al. (2007). Poor sleep is associated with poorer physical performance and greater functional limitations in older women. Sleep. 30(10):1317‐1324.
- Hackett, G. et al. (2017). UK policy statements on testosterone deficiency. International Journal of Clinical Practice, 71(3-4).
- Hackney, A.C. et al. (2012). Testosterone responses to intensive interval versus steady-state endurance exercise. J Endocrinol Invest. 35(11):947‐950.
- Hämäläinen, E. et al. (1984). Diet and serum sex hormones in healthy men. J Steroid Biochem. 20(1):459‐464.
- Hoogeveen, A.R. Et al. (1996). Relationships between testosterone, cortisol and performance in professional cyclists. Int J Sports Med. 17(6):423‐428.
- Herbert, P. et al. (2017). HIIT produces increases in muscle power and free testosterone in male masters athletes. Endocrine connections, 6(7), 430–436.
- Johnston, C.S. et al. (2004). High-protein, low-fat diets are effective for weight loss and favorably alter biomarkers in healthy adults. J Nutr. 134(3):586‐591.
- Kraemer, W. J. et al. (1998). The effects of short-term resistance training on endocrine function in men and women. Eur J Appl Physiol Occup Physiol. 78(1):69‐76.
- Kilic, M. et al. (2006). The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zinc. Neuro Endocrinol Lett. 27(1-2):247‐252.
- Laaksonen, D. E. et al. (2004). Testosterone and Sex Hormone-Binding Globulin Predict the Metabolic Syndrome and Diabetes in Middle-Aged Men. Diabetes Care. May;27(5):1036-41.
- Lado-Abeal, J. et al. (1999). Differences between men and women as regards the effects of protein-energy malnutrition on the hypothalamic-pituitary-gonadal axis. Nutrition. 15(5):351‐358.
- Leproult, R. et al. (2011). Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 305(21):2173‐2174.
- Marín, D. et al. (2007). Variations in urine excretion of steroid hormones after an acute session and after a 4-week programme of strength training. Eur J Appl Physiol. 2007;99(1):65‐71.
- Morford, J. et al. (2016). Sex differences in the effects of androgens acting in the central nervous system on metabolism. Dialogues in Clinical Neuroscience, 18(4), 415.
- Mederos, M. A. et al. (2015). Can Serum Testosterone Be Used as a Marker of Overall Health? Rev Urol. 17(4):226-30.
- Melamed, S. et al. (1999). Chronic burnout, somatic arousal and elevated salivary cortisol levels. J Psychosom Res. 1999;46(6):591‐598.
- McEwen, B.S. (1998). Stress, adaptation, and disease. Allostasis and allostatic load. Ann N Y Acad Sci. 840:33‐44.
- Moncada I. (2006). Testosterone and men’s quality of life. Aging Male. 9(4):189‐193.
- Midzak, A. S. et al. (2011). ATP synthesis, mitochondrial function, and steroid biosynthesis in rodent primary and tumor Leydig cells. Biology of reproduction, 84(5), 976–985.
- Ohlander, S. J. et al. (2018). Erythrocytosis Following Testosterone Therapy. Sexual medicine reviews, 6(1), 77–85.
- Pasquali, R. et al. (1991). Effect of obesity and body fat distribution on sex hormones and insulin in men. Metabolism. 40(1):101‐104.
- Pilz, S. et al. (2011). Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 43(3):223‐225.
- Prasad, A.S. et al. (1996). Zinc status and serum testosterone levels of healthy adults. Nutrition.12(5):344‐348.
- Rossow, L.M. et al. (2013). Natural bodybuilding competition preparation and recovery: a 12-month case study. Int J Sports Physiol Perform. 8(5):582‐592.
- Roland, A.V. et al. (2011). (Regulation of gonadotropin-releasing hormone neurons by glucose. Trends Endocrinol Metab. 22(11):443‐449.
- Reed, M.J. et al. (1987). Dietary lipids: an additional regulator of plasma levels of sex hormone binding globulin. J Clin Endocrinol Metab. 64(5):1083‐1085.
- Rosmond, R. et al. (1998). Stress-related cortisol secretion in men: relationships with abdominal obesity and endocrine, metabolic and hemodynamic abnormalities. J Clin Endocrinol Metab. 83(6):1853‐1859.
- Srinivas-Shankar, U. et al. (2010). Effects of testosterone on muscle strength, physical function, body composition, and quality of life in intermediate-frail and frail elderly men: a randomized, double-blind, placebo-controlled study. J Clin Endocrinol Metab. 95(2):639‐650.
- Sato, K. et al. (2016). Responses of sex steroid hormones to different intensities of exercise in endurance athletes. Exp Physiol. 2016;101(1):168‐175.
- Timón, A. R. et al. (2007). Variations in urine excretion of steroid hormones after an acute session and after a 4-week programme of strength training. Eur J Appl Physiol. 99(1):65‐71.
- Trexler, E.T. et al. (2014). Metabolic adaptation to weight loss: implications for the athlete. J Int Soc Sports Nutr. 11(1):7.
- Toro-Urrego, N. et al. (2016). Testosterone Protects Mitochondrial Function and Regulates Neuroglobin Expression in Astrocytic Cells Exposed to Glucose Deprivation. Frontiers in aging neuroscience, 8, 152.
- Torres, S.J. Et al. (2007). Relationship between stress, eating behavior, and obesity. Nutrition. 23(11-12):887‐894.
- Umeda, F. et al. (1982). Effect of vitamin E on function of pituitary-gonadal axis in male rats and human subjects. Endocrinol Jpn. 29(3):287‐292.
- Volek, J.S. et al. (1997). Testosterone and cortisol in relationship to dietary nutrients and resistance exercise. J Appl Physiol (1985). 82(1):49‐54.
- van der Merwe, J. et al. (2009). Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players. Clin J Sport Med. 19(5):399‐404.
- Vaamonde, D. et al. (2012). Physically active men show better semen parameters and hormone values than sedentary men. Eur J Appl Physiol. 112(9):3267‐3273.
- Vermeulen, A. et al. (1999). Testosterone, body composition and aging. J Endocrinol Invest. 22(5 Suppl):110‐116.
- Vani, K. et al. (2012). Clinical relevance of vitamin C among lead-exposed infertile men. Genet Test Mol Biomarkers. 16(9):1001‐1006.
- Wankhede, S. et al. Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial. J Int Soc Sports Nutr. 2015 Nov 25;12:43.
- Wang, T. J. et al. (2008). Vitamin D deficiency and risk of cardiovascular disease. Circulation, 117(4), 503–511.
- Wang, C. et al. (2011). Low Testosterone Associated With Obesity and the Metabolic Syndrome Contributes to Sexual Dysfunction and Cardiovascular Disease Risk in Men With Type 2 Diabetes. Diabetes Care. Jul;34(7):1669-75.
- Wong, W.Y. et al. (2002). Effects of folic acid and zinc sulfate on male factor subfertility: a double-blind, randomized, placebo-controlled trial. Fertil Steril. 77(3):491‐498.
- Zmuda, J. M. et al. (1997). Longitudinal Relation Between Endogenous Testosterone and Cardiovascular Disease Risk Factors in Middle-Aged Men. A 13-year Follow-Up of Former Multiple Risk Factor Intervention Trial Participants. Am J Epidemiol. Oct 15;146(8):609-17.
- Zarrouf, F.A. Et al. (2009). Testosterone and depression: systematic review and meta-analysis. J Psychiatr Pract. 15(4):289‐305.
- Zeligs, M., A. (1998). Diet and estrogen status: the cruciferous connection. Journal of Medicinal Food, 1(2), 67-82.
- Zittermann, A. et al. (2009). Vitamin D supplementation enhances the beneficial effects of weight loss on cardiovascular disease risk markers. Am J Clin Nutr. 89(5):1321‐1327.
