Is Low T really that bad?
Low Testosterone is associated with lower muscle mass(2), low libido(3), depression(4), low bone density(5), and even death.(6)
There are two main causes of low T. Primary hypogonadism is caused by a problem with the testes. Secondary hypogonadism is caused by imbalances in the bodies hormonal system. As with most health issues diet, lifestyle and exercise play a huge role in Secondary hypogonadism.
War on Cholesterol strikes again!
It isn't surprising that low vitamin D levels are associated with low testosterone (7) since both vitamin D and Testosterone are made from cholesterol. Without cholesterol we cannot make any of our steroid hormones, including testosterone. We have been told to "Go Lower" and try and get our cholesterol as low as possible without realizing that cholesterol is one of the most important molecules in our bodies. (8) There are 65 year old men with low testosterone trying to lower their cholesterol even though studies have shown that in elderly people, those with the highest cholesterol live the longest!!(9) , (10) , (11)
Saturated fat has also been vilified so many men have switched to a low fat diet. Research has shown that low fat diets can reduce Testosterone in middle aged men (12). Saturated and monounsaturated fat intake has been positively associated with testosterone levels (13)
Your Stressing me out!
Lifestyle factors are also associated with low T. Stress can raise cortisol which can lower testosterone. Cortisol levels can also be altered by disruption of circadian rhythms. Too much light late at night from TV and computer screens and not enough bright light in the day can disrupt sleep patterns which can affect Testosterone (14).
Lift Heavy Things!
Most men either don't exercise or don't do enough of the type of exercise that supports Testosterone. Long, steady state, chronic cardio can have the same effect on Cortisol that stress has. Excessive endurance training can cause testosterone and reproductive dysfunction in men (15).
Lifting weights has been shown to increase post workout testosterone levels (16). Sprinting has also been shown to increase testosterone (17). Instead of spending an hour on the treadmill at the gym a better option might be to do a 4 minute tabata sprint training session (18).