estosterone, the major male hormone, apart from regulating the sexual characteristics in men, plays a vital role in promoting and maintaining muscle and bone mass and strength and distribution of body fats. However, the testosterone level tends to decline with age that makes men vulnerable to sexual and other health problems. Despite the popularity of hormone replacement therapy in replenishing the depleted testosterone level, there are a number of natural strategies to boost the level of the major male hormone.
Testosterone is a natural steroid synthesized from cholesterol. In the liver, testosterone is converted into inactive metabolites. It becomes activated when it binds to the androgen receptors. The testicles are the primary sites of testosterone secretion. In females, a small amount of testosterone is secreted in the ovaries. As testosterone is primarily associated with the development of male characteristics, its level is 7 to 8 times higher in adult males than in adult females. Because of the higher level of testosterone metabolism in men, their testosterone production is 20 times higher than in females.
The effect of testosterone on human health is usually categorized into anabolic effects and androgenic effect. Its androgenic effects include maturation of primary and secondary male sex characteristics. Development of male sex organs, a growth of facial and body hair and deepening of voice during puberty are examples of the anabolic effects of androgen. The anabolic effects of testosterone include an increase in mineral density and strength of bones, maturation and linear growth of bones and development of muscles and increased muscle strength. 
Why Testosterone Level Falls
The testosterone level tends to decline after the age of 30. It is believed that the testosterone level decreases by 1% every year after the age of 30 or 40. However, the aging process is not exclusively responsible for the reduction in testosterone level. Low testosterone level could be associated with hypogonadism, a disease that impairs the body’s ability to produce testosterone. A disorder of the testicles or the pituitary gland that regulates the functions of the testicles causes hypogonadism. Low testosterone level could also result from hormonal disorders, type-2 diabetes, obesity, infection, chronic kidney or liver disease, testicular cancer, side effect of treatment for testicular cancer, injury to the testicles and HIV infection or AIDS.
Genetic conditions and side effects of certain medicines can lower the testosterone below the normal level. However, in a number of cases, the exact cause of testosterone deficiency is unclear. The testosterone level is touted to be lower than normal when it is below 300 nanograms per deciliter (ng/dL). Risk of health problems especially bone fragility and risk of fractures is known to increase significantly despite the absence of symptoms when the testosterone level is as low as 200 ng/dL or 100 ng/dL. 
Signs and Symptoms of Low Testosterone
Symptoms that are commonly associated with low testosterone level include:
- Lower Sex Drive: Fall in testosterone affects sexual function. It reduces sexual desire and decreases spontaneous erection. It is also believed to be a cause of male infertility.
- Poor Sleep: In men, the testosterone level is associated with the quality of sleep. It causes sleep disturbances and even insomnia.
- Physical Changes: Decline in testosterone level increases body fat and reduces the lean muscle mass, muscle strength and bone density. It lowers your energy level. Loss of body hair and swelling and tenderness of breasts or gynecomastia are other symptoms of low testosterone.
- Emotional Problems: Depression, poor concentration and lack of self-confidence could be a result of low testosterone level. 
How to Boost Testosterone Naturally
The testosterone level can be increased naturally in various ways.
Exercise stimulates testosterone secretion. The effect of exercise on testosterone production is more pronounced in men than in women. The impact of exercise in stimulating testosterone secretion depends upon the intensity and duration of the exercise. Regardless of the intensity of a workout, an exercise that lasts for less than one minute does not affect the serum testosterone concentration. An exercise of higher intensity that lasts longer causes significant improvement in the testosterone level. However, overtraining decreases the testosterone level. The testosterone level starts declining after exercising for one hour. The testosterone level may fall below the bottom limit after exercising for 3 hours. 
However, exercising occasionally cannot increase your testosterone level. To sustain the elevated testosterone level, exercise should be part of your daily routine. Weight lifting and other strength-training exercises are known to be most effective in boosting the testosterone level. You can expect the best result by working most of your body muscles. A full-body workout is therefore considered superior to exercises that work single muscle groups such as biceps curls. Instead of increasing reps with light weights, consider lifting heavier weights. Weight training with shorter intervals is known to be more effective in increasing testosterone secretion.
The testosterone level changes throughout the day. It is highest in the early morning and lowest in the afternoon. It is advisable to do weight training in the evening. 
2. Reduce Body Weight
Another benefit of exercising is it helps in burning fats and reducing body weight, and in obese and overweight people weight loss is accompanied by increased testosterone level. Overweight men usually have a low testosterone level. Researchers found in a clinical study that overweight middle-aged men with pre-diabetes and low testosterone level who modified their lifestyle on average lost 7.8 kilograms in one year. Reduction in body weight was associated with increased testosterone level. Researchers concluded that the prevalence of low testosterone can be reduced by almost 50 percent by weight loss. 
3. Improve Quality of Sleep
The testosterone production peaks during sleep. Poor sleep including short sleep duration, disruption in the circadian rhythm, abnormalities in sleep qualities, obstructive sleep apnea or sleep-disordered breathing reduces the testosterone level.  In a clinical study, researchers found that daytime testosterone level falls by 10% to 15% in healthy young men who did not sleep for more than 5 hours per night for a week. In contrast, the normal aging process reduces the testosterone levels by 1% to 2% per year.  By addressing the underlying cause of poor sleep, you can easily increase your testosterone level naturally.
4. Intermittent Fasting
Intermittent fasting is believed to be effective in increasing the testosterone level. Consuming more than 300 calories in a single go is known to increase testosterone metabolism. The decrease in testosterone level is equivalent to the amount of testosterone the body produced in three or more hours. However, this does not mean that fasting would boost your testosterone level. It implies that low testosterone can be averted by avoiding food for a certain period of time.  According to a clinical study, short-term fasting helps in increasing testosterone response by almost 180% in non-obese men. 
Another advantage of intermittent fasting is that it helps in burning fats and losing weight quickly that helps in stimulating testosterone production. However, an incorrect fasting strategy would wreak havoc on your health and would end up lowering your testosterone level further. Instead of starving for a prolonged period of time, consume only smoothies on one day in a week and in other days in addition to one or two smoothies, eat whole-food meals along with healthy snacks and desserts. 
5. Detox Diet
The huge chemical load that the human body carries nowadays is believed to be a possible cause of low testosterone. A detox diet helps in eliminating the toxic chemicals and excess hormones from the body that could help in restoring the normal plasma testosterone concentration. A detox diet is believed to reduce stress on the body that decreases the cortisol level. The stress hormone cortisol is known to suppress testosterone production. 
6. Eat Zinc Rich Foods
Zinc plays an important role in testosterone synthesis. Therefore, zinc deficiency reduces testosterone production. In men, severe to moderate zinc deficiency causes hypogonadism. Zinc supports the normal functions of the pituitary gland. The pituitary gland releases hormones that stimulate the testicles to produce testosterone. Furthermore, zinc obstructs aromatase, an enzyme responsible for converting testosterone into estrogen. In addition to a zinc-deficient diet, alcohol or drug abuse leads to zinc deficiency. Clinical studies suggest zinc supplementation can help in offsetting the adverse effect of marginally zinc-deficient diet.  Oysters are the best source of zinc. By consuming 3 ounces of oysters, you will get a whopping 493 of the Daily Value (DV) of zinc. Other good food sources of zinc are a crab, lobster, pork, beans, chicken, yogurt and cashews. 
7. Have More Vitamin D
A number of cross-sectional studies have found a positive correlation between serum vitamin D and testosterone levels in men more than 50 years old. Seasonal fluctuations in both testosterone and vitamin D levels have been observed in studies. A study had shown that regular intake of 83 microgram vitamin D for one year helped in increasing the total testosterone level by 25%. However, research suggests that supplementation with vitamin D could increase the testosterone level only when serum vitamin D level is below 75 to 85 nmol/L. The positive association reaches a plateau when the serum vitamin D concentration rises above 85nmol/L.  There are few food sources of vitamin D such as fatty fish, fish liver oil, egg yolk, and cheese. Exposure to sunlight helps in stimulating vitamin D synthesis in your body naturally. 
8. Add More Vitamin K Rich Foods to Diet
Vitamin K deficiency is a possible cause of low testosterone. Studies using animal models have shown that vitamin K deficient diet reduces testicular testosterone secretion. Increasing consumption of foods rich in vitamin K can, therefore, help in maintaining the steady testosterone level.  You can easily enhance your vitamin K intake by eating more leafy green vegetables such as collards, turnip green, spinach, kale and broccoli. 
9. Eat Healthy Fats
A fat-restricted diet is known to lower the testosterone level. In a clinical study, the customary diet of a group of healthy men was replaced by a low-fat diet. In the customary diet, 40% of energy came from fats primarily from animal sources. In the low-fat diet, not more than 25% of energy was provided by fats. After the 6-week study period, researchers found that the low-fat diet reduced the serum testosterone concentration. The study also indicated that less consumption of saturated fatty acids and increased intake of unsaturated fat can have an adverse effect on testosterone production. 
10. Take BCAA Supplement
Leucine, isoleucine, and valine are the three branched-chain amino acids (BCAAs). BCAA supplements contain these amino acids in the ratio of 2:1:1. By consuming 5 grams of BCAA supplement you will get 2.5 grams of leucine and 1.25 grams each of isoleucine and valine. BCAA supplement taken before and after workout sessions is known to boost the testosterone level. According to a study, BCAA supplementation for four weeks during high-intensity resistance training significantly increased the serum testosterone level.  Ingesting whole milk protein from which the BCAAs had been removed was found to reduce the free testosterone level. BCAA intake is therefore believed to reduce metabolic testosterone clearance during high-intensity exercise. Pre-exercise BCAA supplementation helped in maintaining the pre-exercise testosterone level after the workout session and increased the testosterone level during the rest period. 
11. Try Herbs
Certain herbs are believed to help in stimulating testosterone production. It may take several weeks to elevate the testosterone level with herbs. In most cases, the testosterone level boosted by herbs can be maintained at a high level for several months. However, herbalists warn against overuse of herbs. It is advisable to stop using the herbs after a few months. Some of the herbs that are commonly used for increasing the testosterone level include wild oats or Avena, Siberian ginseng, stinging nettle, Muira puama, and Tribulus Terrestris. 
12. Manage Stress
The hormone cortisol produced during stress is known to suppress testosterone production. Both testosterone and the stress hormone are classified as steroids. Hence, increased production of one steroid hormone is associated with decreased production of the other steroid hormone. Studies have shown that the testosterone level is restored to the normal level when stress is reduced.  Practicing stress management techniques could help you to cope with stress and maintain a healthy testosterone level.