One of the unwanted side effects of chronic stress, including constant athletic over-training and competition, is impotence, loss of sex drive and fewer sperm, most of which are not good swimmers. I'm not an expert on the matter but I will do my best to explain the basics of what is going on and what to do about it. It will also become clear that messing with one's cholesterol with drugs and low fat diets diets may render you sexually impotent and generally tired and unwell.
Please click on the link above to visit Dr Linda's wonderful website to learn more about hormones and health and to check out her professional services.
The chart above is a simplified depiction of the Steroid Hormone Cascade which is the process by which LDL cholesterol, including many other essential nutrients, including the fat soluble vitamins, is converted into the steroidal hormones, including oestrogen, progesterone and testosterone. These hormones must be plentiful and in balance for a person to feel in good health, fit, strong, sexually potent, fertile and emotionally balanced.
This applies as much to women as it does for men (In women the adrenal glands produce 100% of their testosterone requirements). The adrenal glands regulate the stress responses, so are easily damaged by the modern lifestyle, including excessive exercise, such as running marathons.
During times of health, relaxation, good food and moderate exercise (which should always be life's norm), cholesterol and other nutrients will enter the hormone production factories of the body where they cascade downwards a little like the balls in a pinball game. Depending on the needs of the moment, the tumbling molecules are diverted left, or right, producing the many hormones that are required to maintain normal, healthy function at that moment in time.
Stress can mess up your hormones
If there is excessive or ongoing stress, cortisol production becomes the priority. Cortisol and cortisone are the stress hormones which regulate the "fight or flight" response to stress. If you are in the middle of attack there is not going to be any sex and getting pregnant then is not good timing, so the temporary diversion of most of the hormone precursors to the pathway that produces cortisone is not a problem - in fact, this diversion is critical for survival. However, if this happens continuously, especially if the diet is low in cholesterol, or if taking drugs that interfere with cholesterol (which means fewer nutrient balls to play the Hormone Cascade to start with!), the consequences of depressed sex hormones gradually begin to show and health deteriorates. Low testosterone in men relative to estrogen = MAN BOOBS and the droops! It's not at all good for women either. Women must have testosterone along with all the other hormones - and in a precise balance.
This is why stress is bad for your sex life and fertility (male and female). This also helps explain why women who live stressful lives and eat poorly tend to go through menopause with severe symptoms; whereas women who lead relatively relaxed lives with a nutrient dense diet tend to cruise through the Change.